In the Linux kernel, the following vulnerability has been resolved: ext4: fix race condition between ext4_write and ext4_convert_inline_data Hulk Robot reported a BUG_ON: ================================================================== EXT4-fs error (device loop3): ext4_mb_generate_buddy:805: group 0, block bitmap and bg descriptor inconsistent: 25 vs 31513 free clusters kernel BUG at fs/ext4/ext4_jbd2.c:53! invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 0 PID: 25371 Comm: syz-executor.3 Not tainted 5.10.0+ #1 RIP: 0010:ext4_put_nojournal fs/ext4/ext4_jbd2.c:53 [inline] RIP: 0010:__ext4_journal_stop+0x10e/0x110 fs/ext4/ext4_jbd2.c:116 [...] Call Trace: ext4_write_inline_data_end+0x59a/0x730 fs/ext4/inline.c:795 generic_perform_write+0x279/0x3c0 mm/filemap.c:3344 ext4_buffered_write_iter+0x2e3/0x3d0 fs/ext4/file.c:270 ext4_file_write_iter+0x30a/0x11c0 fs/ext4/file.c:520 do_iter_readv_writev+0x339/0x3c0 fs/read_write.c:732 do_iter_write+0x107/0x430 fs/read_write.c:861 vfs_writev fs/read_write.c:934 [inline] do_pwritev+0x1e5/0x380 fs/read_write.c:1031 [...] ================================================================== Above issue may happen as follows: cpu1 cpu2 __________________________|__________________________ do_pwritev vfs_writev do_iter_write ext4_file_write_iter ext4_buffered_write_iter generic_perform_write ext4_da_write_begin vfs_fallocate ext4_fallocate ext4_convert_inline_data ext4_convert_inline_data_nolock ext4_destroy_inline_data_nolock clear EXT4_STATE_MAY_INLINE_DATA ext4_map_blocks ext4_ext_map_blocks ext4_mb_new_blocks ext4_mb_regular_allocator ext4_mb_good_group_nolock ext4_mb_init_group ext4_mb_init_cache ext4_mb_generate_buddy --> error ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) ext4_restore_inline_data set EXT4_STATE_MAY_INLINE_DATA ext4_block_write_begin ext4_da_write_end ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) ext4_write_inline_data_end handle=NULL ext4_journal_stop(handle) __ext4_journal_stop ext4_put_nojournal(handle) ref_cnt = (unsigned long)handle BUG_ON(ref_cnt == 0) ---> BUG_ON The lock held by ext4_convert_inline_data is xattr_sem, but the lock held by generic_perform_write is i_rwsem. Therefore, the two locks can be concurrent. To solve above issue, we add inode_lock() for ext4_convert_inline_data(). At the same time, move ext4_convert_inline_data() in front of ext4_punch_hole(), remove similar handling from ext4_punch_hole().

In the Linux kernel, the following vulnerability has been resolved: sock_map: avoid race between sock_map_close and sk_psock_put sk_psock_get will return NULL if the refcount of psock has gone to 0, which will happen when the last call of sk_psock_put is done. However, sk_psock_drop may not have finished yet, so the close callback will still point to sock_map_close despite psock being NULL. This can be reproduced with a thread deleting an element from the sock map, while the second one creates a socket, adds it to the map and closes it. That will trigger the WARN_ON_ONCE: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 7220 at net/core/sock_map.c:1701 sock_map_close+0x2a2/0x2d0 net/core/sock_map.c:1701 Modules linked in: CPU: 1 PID: 7220 Comm: syz-executor380 Not tainted 6.9.0-syzkaller-07726-g3c999d1ae3c7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:sock_map_close+0x2a2/0x2d0 net/core/sock_map.c:1701 Code: df e8 92 29 88 f8 48 8b 1b 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 79 29 88 f8 4c 8b 23 eb 89 e8 4f 15 23 f8 90 <0f> 0b 90 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 13 26 3d 02 RSP: 0018:ffffc9000441fda8 EFLAGS: 00010293 RAX: ffffffff89731ae1 RBX: ffffffff94b87540 RCX: ffff888029470000 RDX: 0000000000000000 RSI: ffffffff8bcab5c0 RDI: ffffffff8c1faba0 RBP: 0000000000000000 R08: ffffffff92f9b61f R09: 1ffffffff25f36c3 R10: dffffc0000000000 R11: fffffbfff25f36c4 R12: ffffffff89731840 R13: ffff88804b587000 R14: ffff88804b587000 R15: ffffffff89731870 FS: 000055555e080380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000207d4000 CR4: 0000000000350ef0 Call Trace: <TASK> unix_release+0x87/0xc0 net/unix/af_unix.c:1048 __sock_release net/socket.c:659 [inline] sock_close+0xbe/0x240 net/socket.c:1421 __fput+0x42b/0x8a0 fs/file_table.c:422 __do_sys_close fs/open.c:1556 [inline] __se_sys_close fs/open.c:1541 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb37d618070 Code: 00 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d4 e8 10 2c 00 00 80 3d 31 f0 07 00 00 74 17 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c RSP: 002b:00007ffcd4a525d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fb37d618070 RDX: 0000000000000010 RSI: 00000000200001c0 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000100000000 R09: 0000000100000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Use sk_psock, which will only check that the pointer is not been set to NULL yet, which should only happen after the callbacks are restored. If, then, a reference can still be gotten, we may call sk_psock_stop and cancel psock->work. As suggested by Paolo Abeni, reorder the condition so the control flow is less convoluted. After that change, the reproducer does not trigger the WARN_ON_ONCE anymore.

In the Linux kernel, the following vulnerability has been resolved: accel/ivpu: Prevent recovery invocation during probe and resume Refactor IPC send and receive functions to allow correct handling of operations that should not trigger a recovery process. Expose ivpu_send_receive_internal(), which is now utilized by the D0i3 entry, DCT initialization, and HWS initialization functions. These functions have been modified to return error codes gracefully, rather than initiating recovery. The updated functions are invoked within ivpu_probe() and ivpu_resume(), ensuring that any errors encountered during these stages result in a proper teardown or shutdown sequence. The previous approach of triggering recovery within these functions could lead to a race condition, potentially causing undefined behavior and kernel crashes due to null pointer dereferences.

In the Linux kernel, the following vulnerability has been resolved: iommu/arm-smmu: Defer probe of clients after smmu device bound Null pointer dereference occurs due to a race between smmu driver probe and client driver probe, when of_dma_configure() for client is called after the iommu_device_register() for smmu driver probe has executed but before the driver_bound() for smmu driver has been called. Following is how the race occurs: T1:Smmu device probe T2: Client device probe really_probe() arm_smmu_device_probe() iommu_device_register() really_probe() platform_dma_configure() of_dma_configure() of_dma_configure_id() of_iommu_configure() iommu_probe_device() iommu_init_device() arm_smmu_probe_device() arm_smmu_get_by_fwnode() driver_find_device_by_fwnode() driver_find_device() next_device() klist_next() /* null ptr assigned to smmu */ /* null ptr dereference while smmu->streamid_mask */ driver_bound() klist_add_tail() When this null smmu pointer is dereferenced later in arm_smmu_probe_device, the device crashes. Fix this by deferring the probe of the client device until the smmu device has bound to the arm smmu driver. [will: Add comment]

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to check atomic_file in f2fs ioctl interfaces Some f2fs ioctl interfaces like f2fs_ioc_set_pin_file(), f2fs_move_file_range(), and f2fs_defragment_range() missed to check atomic_write status, which may cause potential race issue, fix it.

In the Linux kernel, the following vulnerability has been resolved: net: xilinx: axienet: Enqueue Tx packets in dql before dmaengine starts Enqueue packets in dql after dma engine starts causes race condition. Tx transfer starts once dma engine is started and may execute dql dequeue in completion before it gets queued. It results in following kernel crash while running iperf stress test: kernel BUG at lib/dynamic_queue_limits.c:99! <snip> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP pc : dql_completed+0x238/0x248 lr : dql_completed+0x3c/0x248 Call trace: dql_completed+0x238/0x248 axienet_dma_tx_cb+0xa0/0x170 xilinx_dma_do_tasklet+0xdc/0x290 tasklet_action_common+0xf8/0x11c tasklet_action+0x30/0x3c handle_softirqs+0xf8/0x230 <snip> Start dmaengine after enqueue in dql fixes the crash.

In the Linux kernel, the following vulnerability has been resolved: nvme-pci: fix race condition between reset and nvme_dev_disable() nvme_dev_disable() modifies the dev->online_queues field, therefore nvme_pci_update_nr_queues() should avoid racing against it, otherwise we could end up passing invalid values to blk_mq_update_nr_hw_queues(). WARNING: CPU: 39 PID: 61303 at drivers/pci/msi/api.c:347 pci_irq_get_affinity+0x187/0x210 Workqueue: nvme-reset-wq nvme_reset_work [nvme] RIP: 0010:pci_irq_get_affinity+0x187/0x210 Call Trace: <TASK> ? blk_mq_pci_map_queues+0x87/0x3c0 ? pci_irq_get_affinity+0x187/0x210 blk_mq_pci_map_queues+0x87/0x3c0 nvme_pci_map_queues+0x189/0x460 [nvme] blk_mq_update_nr_hw_queues+0x2a/0x40 nvme_reset_work+0x1be/0x2a0 [nvme] Fix the bug by locking the shutdown_lock mutex before using dev->online_queues. Give up if nvme_dev_disable() is running or if it has been executed already.

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix a race between socket set up and I/O thread creation In rxrpc_open_socket(), it sets up the socket and then sets up the I/O thread that will handle it. This is a problem, however, as there's a gap between the two phases in which a packet may come into rxrpc_encap_rcv() from the UDP packet but we oops when trying to wake the not-yet created I/O thread. As a quick fix, just make rxrpc_encap_rcv() discard the packet if there's no I/O thread yet. A better, but more intrusive fix would perhaps be to rearrange things such that the socket creation is done by the I/O thread.

In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Ensure DA_ID handling completion before deleting an NPIV instance Deleting an NPIV instance requires all fabric ndlps to be released before an NPIV's resources can be torn down. Failure to release fabric ndlps beforehand opens kref imbalance race conditions. Fix by forcing the DA_ID to complete synchronously with usage of wait_queue.

In the Linux kernel, the following vulnerability has been resolved: drm/panthor: Fix race when converting group handle to group object XArray provides it's own internal lock which protects the internal array when entries are being simultaneously added and removed. However there is still a race between retrieving the pointer from the XArray and incrementing the reference count. To avoid this race simply hold the internal XArray lock when incrementing the reference count, this ensures there cannot be a racing call to xa_erase().

In the Linux kernel, the following vulnerability has been resolved: lib/generic-radix-tree.c: Fix rare race in __genradix_ptr_alloc() If we need to increase the tree depth, allocate a new node, and then race with another thread that increased the tree depth before us, we'll still have a preallocated node that might be used later. If we then use that node for a new non-root node, it'll still have a pointer to the old root instead of being zeroed - fix this by zeroing it in the cmpxchg failure path.

Race condition in the ext4_file_write_iter function in fs/ext4/file.c in the Linux kernel through 3.17 allows local users to cause a denial of service (file unavailability) via a combination of a write action and an F_SETFL fcntl operation for the O_DIRECT flag.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Always drain health in shutdown callback There is no point in recovery during device shutdown. if health work started need to wait for it to avoid races and NULL pointer access. Hence, drain health WQ on shutdown callback.

In the Linux kernel, the following vulnerability has been resolved: af_unix: Fix garbage collector racing against connect() Garbage collector does not take into account the risk of embryo getting enqueued during the garbage collection. If such embryo has a peer that carries SCM_RIGHTS, two consecutive passes of scan_children() may see a different set of children. Leading to an incorrectly elevated inflight count, and then a dangling pointer within the gc_inflight_list. sockets are AF_UNIX/SOCK_STREAM S is an unconnected socket L is a listening in-flight socket bound to addr, not in fdtable V's fd will be passed via sendmsg(), gets inflight count bumped connect(S, addr) sendmsg(S, [V]); close(V) __unix_gc() ---------------- ------------------------- ----------- NS = unix_create1() skb1 = sock_wmalloc(NS) L = unix_find_other(addr) unix_state_lock(L) unix_peer(S) = NS // V count=1 inflight=0 NS = unix_peer(S) skb2 = sock_alloc() skb_queue_tail(NS, skb2[V]) // V became in-flight // V count=2 inflight=1 close(V) // V count=1 inflight=1 // GC candidate condition met for u in gc_inflight_list: if (total_refs == inflight_refs) add u to gc_candidates // gc_candidates={L, V} for u in gc_candidates: scan_children(u, dec_inflight) // embryo (skb1) was not // reachable from L yet, so V's // inflight remains unchanged __skb_queue_tail(L, skb1) unix_state_unlock(L) for u in gc_candidates: if (u.inflight) scan_children(u, inc_inflight_move_tail) // V count=1 inflight=2 (!) If there is a GC-candidate listening socket, lock/unlock its state. This makes GC wait until the end of any ongoing connect() to that socket. After flipping the lock, a possibly SCM-laden embryo is already enqueued. And if there is another embryo coming, it can not possibly carry SCM_RIGHTS. At this point, unix_inflight() can not happen because unix_gc_lock is already taken. Inflight graph remains unaffected.

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix race between direct IO write and fsync when using same fd If we have 2 threads that are using the same file descriptor and one of them is doing direct IO writes while the other is doing fsync, we have a race where we can end up either: 1) Attempt a fsync without holding the inode's lock, triggering an assertion failures when assertions are enabled; 2) Do an invalid memory access from the fsync task because the file private points to memory allocated on stack by the direct IO task and it may be used by the fsync task after the stack was destroyed. The race happens like this: 1) A user space program opens a file descriptor with O_DIRECT; 2) The program spawns 2 threads using libpthread for example; 3) One of the threads uses the file descriptor to do direct IO writes, while the other calls fsync using the same file descriptor. 4) Call task A the thread doing direct IO writes and task B the thread doing fsyncs; 5) Task A does a direct IO write, and at btrfs_direct_write() sets the file's private to an on stack allocated private with the member 'fsync_skip_inode_lock' set to true; 6) Task B enters btrfs_sync_file() and sees that there's a private structure associated to the file which has 'fsync_skip_inode_lock' set to true, so it skips locking the inode's VFS lock; 7) Task A completes the direct IO write, and resets the file's private to NULL since it had no prior private and our private was stack allocated. Then it unlocks the inode's VFS lock; 8) Task B enters btrfs_get_ordered_extents_for_logging(), then the assertion that checks the inode's VFS lock is held fails, since task B never locked it and task A has already unlocked it. The stack trace produced is the following: assertion failed: inode_is_locked(&inode->vfs_inode), in fs/btrfs/ordered-data.c:983 ------------[ cut here ]------------ kernel BUG at fs/btrfs/ordered-data.c:983! Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 9 PID: 5072 Comm: worker Tainted: G U OE 6.10.5-1-default #1 openSUSE Tumbleweed 69f48d427608e1c09e60ea24c6c55e2ca1b049e8 Hardware name: Acer Predator PH315-52/Covini_CFS, BIOS V1.12 07/28/2020 RIP: 0010:btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs] Code: 50 d6 86 c0 e8 (...) RSP: 0018:ffff9e4a03dcfc78 EFLAGS: 00010246 RAX: 0000000000000054 RBX: ffff9078a9868e98 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff907dce4a7800 RDI: ffff907dce4a7800 RBP: ffff907805518800 R08: 0000000000000000 R09: ffff9e4a03dcfb38 R10: ffff9e4a03dcfb30 R11: 0000000000000003 R12: ffff907684ae7800 R13: 0000000000000001 R14: ffff90774646b600 R15: 0000000000000000 FS: 00007f04b96006c0(0000) GS:ffff907dce480000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f32acbfc000 CR3: 00000001fd4fa005 CR4: 00000000003726f0 Call Trace: <TASK> ? __die_body.cold+0x14/0x24 ? die+0x2e/0x50 ? do_trap+0xca/0x110 ? do_error_trap+0x6a/0x90 ? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] ? exc_invalid_op+0x50/0x70 ? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] ? asm_exc_invalid_op+0x1a/0x20 ? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] ? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] btrfs_sync_file+0x21a/0x4d0 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] ? __seccomp_filter+0x31d/0x4f0 __x64_sys_fdatasync+0x4f/0x90 do_syscall_64+0x82/0x160 ? do_futex+0xcb/0x190 ? __x64_sys_futex+0x10e/0x1d0 ? switch_fpu_return+0x4f/0xd0 ? syscall_exit_to_user_mode+0x72/0x220 ? do_syscall_64+0x8e/0x160 ? syscall_exit_to_user_mod ---truncated---

In the Linux kernel, the following vulnerability has been resolved: KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() Use {READ,WRITE}_ONCE() to access kvm->last_boosted_vcpu to ensure the loads and stores are atomic. In the extremely unlikely scenario the compiler tears the stores, it's theoretically possible for KVM to attempt to get a vCPU using an out-of-bounds index, e.g. if the write is split into multiple 8-bit stores, and is paired with a 32-bit load on a VM with 257 vCPUs: CPU0 CPU1 last_boosted_vcpu = 0xff; (last_boosted_vcpu = 0x100) last_boosted_vcpu[15:8] = 0x01; i = (last_boosted_vcpu = 0x1ff) last_boosted_vcpu[7:0] = 0x00; vcpu = kvm->vcpu_array[0x1ff]; As detected by KCSAN: BUG: KCSAN: data-race in kvm_vcpu_on_spin [kvm] / kvm_vcpu_on_spin [kvm] write to 0xffffc90025a92344 of 4 bytes by task 4340 on cpu 16: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4112) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) read to 0xffffc90025a92344 of 4 bytes by task 4342 on cpu 4: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4069) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) value changed: 0x00000012 -> 0x00000000

In the Linux kernel, the following vulnerability has been resolved: netfilter: bridge: confirm multicast packets before passing them up the stack conntrack nf_confirm logic cannot handle cloned skbs referencing the same nf_conn entry, which will happen for multicast (broadcast) frames on bridges. Example: macvlan0 | br0 / \ ethX ethY ethX (or Y) receives a L2 multicast or broadcast packet containing an IP packet, flow is not yet in conntrack table. 1. skb passes through bridge and fake-ip (br_netfilter)Prerouting. -> skb->_nfct now references a unconfirmed entry 2. skb is broad/mcast packet. bridge now passes clones out on each bridge interface. 3. skb gets passed up the stack. 4. In macvlan case, macvlan driver retains clone(s) of the mcast skb and schedules a work queue to send them out on the lower devices. The clone skb->_nfct is not a copy, it is the same entry as the original skb. The macvlan rx handler then returns RX_HANDLER_PASS. 5. Normal conntrack hooks (in NF_INET_LOCAL_IN) confirm the orig skb. The Macvlan broadcast worker and normal confirm path will race. This race will not happen if step 2 already confirmed a clone. In that case later steps perform skb_clone() with skb->_nfct already confirmed (in hash table). This works fine. But such confirmation won't happen when eb/ip/nftables rules dropped the packets before they reached the nf_confirm step in postrouting. Pablo points out that nf_conntrack_bridge doesn't allow use of stateful nat, so we can safely discard the nf_conn entry and let inet call conntrack again. This doesn't work for bridge netfilter: skb could have a nat transformation. Also bridge nf prevents re-invocation of inet prerouting via 'sabotage_in' hook. Work around this problem by explicit confirmation of the entry at LOCAL_IN time, before upper layer has a chance to clone the unconfirmed entry. The downside is that this disables NAT and conntrack helpers. Alternative fix would be to add locking to all code parts that deal with unconfirmed packets, but even if that could be done in a sane way this opens up other problems, for example: -m physdev --physdev-out eth0 -j SNAT --snat-to 1.2.3.4 -m physdev --physdev-out eth1 -j SNAT --snat-to 1.2.3.5 For multicast case, only one of such conflicting mappings will be created, conntrack only handles 1:1 NAT mappings. Users should set create a setup that explicitly marks such traffic NOTRACK (conntrack bypass) to avoid this, but we cannot auto-bypass them, ruleset might have accept rules for untracked traffic already, so user-visible behaviour would change.

In the Linux kernel, the following vulnerability has been resolved: dmaengine: dw-edma: eDMA: Add sync read before starting the DMA transfer in remote setup The Linked list element and pointer are not stored in the same memory as the eDMA controller register. If the doorbell register is toggled before the full write of the linked list a race condition error will occur. In remote setup we can only use a readl to the memory to assure the full write has occurred.

In the Linux kernel, the following vulnerability has been resolved: netrom: Fix data-races around sysctl_net_busy_read We need to protect the reader reading the sysctl value because the value can be changed concurrently.

In the Linux kernel, the following vulnerability has been resolved: netpoll: Fix race condition in netpoll_owner_active KCSAN detected a race condition in netpoll: BUG: KCSAN: data-race in net_rx_action / netpoll_send_skb write (marked) to 0xffff8881164168b0 of 4 bytes by interrupt on cpu 10: net_rx_action (./include/linux/netpoll.h:90 net/core/dev.c:6712 net/core/dev.c:6822) <snip> read to 0xffff8881164168b0 of 4 bytes by task 1 on cpu 2: netpoll_send_skb (net/core/netpoll.c:319 net/core/netpoll.c:345 net/core/netpoll.c:393) netpoll_send_udp (net/core/netpoll.c:?) <snip> value changed: 0x0000000a -> 0xffffffff This happens because netpoll_owner_active() needs to check if the current CPU is the owner of the lock, touching napi->poll_owner non atomically. The ->poll_owner field contains the current CPU holding the lock. Use an atomic read to check if the poll owner is the current CPU.

In the Linux kernel, the following vulnerability has been resolved: wifi: ath9k: delay all of ath9k_wmi_event_tasklet() until init is complete The ath9k_wmi_event_tasklet() used in ath9k_htc assumes that all the data structures have been fully initialised by the time it runs. However, because of the order in which things are initialised, this is not guaranteed to be the case, because the device is exposed to the USB subsystem before the ath9k driver initialisation is completed. We already committed a partial fix for this in commit: 8b3046abc99e ("ath9k_htc: fix NULL pointer dereference at ath9k_htc_tx_get_packet()") However, that commit only aborted the WMI_TXSTATUS_EVENTID command in the event tasklet, pairing it with an "initialisation complete" bit in the TX struct. It seems syzbot managed to trigger the race for one of the other commands as well, so let's just move the existing synchronisation bit to cover the whole tasklet (setting it at the end of ath9k_htc_probe_device() instead of inside ath9k_tx_init()).

In the Linux kernel, the following vulnerability has been resolved: net: bridge: switchdev: Skip MDB replays of deferred events on offload Before this change, generation of the list of MDB events to replay would race against the creation of new group memberships, either from the IGMP/MLD snooping logic or from user configuration. While new memberships are immediately visible to walkers of br->mdb_list, the notification of their existence to switchdev event subscribers is deferred until a later point in time. So if a replay list was generated during a time that overlapped with such a window, it would also contain a replay of the not-yet-delivered event. The driver would thus receive two copies of what the bridge internally considered to be one single event. On destruction of the bridge, only a single membership deletion event was therefore sent. As a consequence of this, drivers which reference count memberships (at least DSA), would be left with orphan groups in their hardware database when the bridge was destroyed. This is only an issue when replaying additions. While deletion events may still be pending on the deferred queue, they will already have been removed from br->mdb_list, so no duplicates can be generated in that scenario. To a user this meant that old group memberships, from a bridge in which a port was previously attached, could be reanimated (in hardware) when the port joined a new bridge, without the new bridge's knowledge. For example, on an mv88e6xxx system, create a snooping bridge and immediately add a port to it: root@infix-06-0b-00:~$ ip link add dev br0 up type bridge mcast_snooping 1 && \ > ip link set dev x3 up master br0 And then destroy the bridge: root@infix-06-0b-00:~$ ip link del dev br0 root@infix-06-0b-00:~$ mvls atu ADDRESS FID STATE Q F 0 1 2 3 4 5 6 7 8 9 a DEV:0 Marvell 88E6393X 33:33:00:00:00:6a 1 static - - 0 . . . . . . . . . . 33:33:ff:87:e4:3f 1 static - - 0 . . . . . . . . . . ff:ff:ff:ff:ff:ff 1 static - - 0 1 2 3 4 5 6 7 8 9 a root@infix-06-0b-00:~$ The two IPv6 groups remain in the hardware database because the port (x3) is notified of the host's membership twice: once via the original event and once via a replay. Since only a single delete notification is sent, the count remains at 1 when the bridge is destroyed. Then add the same port (or another port belonging to the same hardware domain) to a new bridge, this time with snooping disabled: root@infix-06-0b-00:~$ ip link add dev br1 up type bridge mcast_snooping 0 && \ > ip link set dev x3 up master br1 All multicast, including the two IPv6 groups from br0, should now be flooded, according to the policy of br1. But instead the old memberships are still active in the hardware database, causing the switch to only forward traffic to those groups towards the CPU (port 0). Eliminate the race in two steps: 1. Grab the write-side lock of the MDB while generating the replay list. This prevents new memberships from showing up while we are generating the replay list. But it leaves the scenario in which a deferred event was already generated, but not delivered, before we grabbed the lock. Therefore: 2. Make sure that no deferred version of a replay event is already enqueued to the switchdev deferred queue, before adding it to the replay list, when replaying additions.

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix disconnect vs accept race Despite commit 0ad529d9fd2b ("mptcp: fix possible divide by zero in recvmsg()"), the mptcp protocol is still prone to a race between disconnect() (or shutdown) and accept. The root cause is that the mentioned commit checks the msk-level flag, but mptcp_stream_accept() does acquire the msk-level lock, as it can rely directly on the first subflow lock. As reported by Christoph than can lead to a race where an msk socket is accepted after that mptcp_subflow_queue_clean() releases the listener socket lock and just before it takes destructive actions leading to the following splat: BUG: kernel NULL pointer dereference, address: 0000000000000012 PGD 5a4ca067 P4D 5a4ca067 PUD 37d4c067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 2 PID: 10955 Comm: syz-executor.5 Not tainted 6.5.0-rc1-gdc7b257ee5dd #37 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 RIP: 0010:mptcp_stream_accept+0x1ee/0x2f0 include/net/inet_sock.h:330 Code: 0a 09 00 48 8b 1b 4c 39 e3 74 07 e8 bc 7c 7f fe eb a1 e8 b5 7c 7f fe 4c 8b 6c 24 08 eb 05 e8 a9 7c 7f fe 49 8b 85 d8 09 00 00 <0f> b6 40 12 88 44 24 07 0f b6 6c 24 07 bf 07 00 00 00 89 ee e8 89 RSP: 0018:ffffc90000d07dc0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff888037e8d020 RCX: ffff88803b093300 RDX: 0000000000000000 RSI: ffffffff833822c5 RDI: ffffffff8333896a RBP: 0000607f82031520 R08: ffff88803b093300 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000003e83 R12: ffff888037e8d020 R13: ffff888037e8c680 R14: ffff888009af7900 R15: ffff888009af6880 FS: 00007fc26d708640(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000012 CR3: 0000000066bc5001 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> do_accept+0x1ae/0x260 net/socket.c:1872 __sys_accept4+0x9b/0x110 net/socket.c:1913 __do_sys_accept4 net/socket.c:1954 [inline] __se_sys_accept4 net/socket.c:1951 [inline] __x64_sys_accept4+0x20/0x30 net/socket.c:1951 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Address the issue by temporary removing the pending request socket from the accept queue, so that racing accept() can't touch them. After depleting the msk - the ssk still exists, as plain TCP sockets, re-insert them into the accept queue, so that later inet_csk_listen_stop() will complete the tcp socket disposal.

In the Linux kernel, the following vulnerability has been resolved: wifi: rtw89: fix potential race condition between napi_init and napi_enable A race condition can happen if netdev is registered, but NAPI isn't initialized yet, and meanwhile user space starts the netdev that will enable NAPI. Then, it hits BUG_ON(): kernel BUG at net/core/dev.c:6423! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 417 Comm: iwd Not tainted 6.2.7-slab-dirty #3 eb0f5a8a9d91 Hardware name: LENOVO 21DL/LNVNB161216, BIOS JPCN20WW(V1.06) 09/20/2022 RIP: 0010:napi_enable+0x3f/0x50 Code: 48 89 c2 48 83 e2 f6 f6 81 89 08 00 00 02 74 0d 48 83 ... RSP: 0018:ffffada1414f3548 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffa01425802080 RCX: 0000000000000000 RDX: 00000000000002ff RSI: ffffada14e50c614 RDI: ffffa01425808dc0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000100 R12: ffffa01425808f58 R13: 0000000000000000 R14: ffffa01423498940 R15: 0000000000000001 FS: 00007f5577c0a740(0000) GS:ffffa0169fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5577a19972 CR3: 0000000125a7a000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> rtw89_pci_ops_start+0x1c/0x70 [rtw89_pci 6cbc75429515c181cbc386478d5cfb32ffc5a0f8] rtw89_core_start+0xbe/0x160 [rtw89_core fe07ecb874820b6d778370d4acb6ef8a37847f22] rtw89_ops_start+0x26/0x40 [rtw89_core fe07ecb874820b6d778370d4acb6ef8a37847f22] drv_start+0x42/0x100 [mac80211 c07fa22af8c3cf3f7d7ab3884ca990784d72e2d2] ieee80211_do_open+0x311/0x7d0 [mac80211 c07fa22af8c3cf3f7d7ab3884ca990784d72e2d2] ieee80211_open+0x6a/0x90 [mac80211 c07fa22af8c3cf3f7d7ab3884ca990784d72e2d2] __dev_open+0xe0/0x180 __dev_change_flags+0x1da/0x250 dev_change_flags+0x26/0x70 do_setlink+0x37c/0x12c0 ? ep_poll_callback+0x246/0x290 ? __nla_validate_parse+0x61/0xd00 ? __wake_up_common_lock+0x8f/0xd0 To fix this, follow Jonas' suggestion to switch the order of these functions and move register netdev to be the last step of PCI probe. Also, correct the error handling of rtw89_core_register_hw().

In the Linux kernel, the following vulnerability has been resolved: f2fs: don't reset unchangable mount option in f2fs_remount() syzbot reports a bug as below: general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:__lock_acquire+0x69/0x2000 kernel/locking/lockdep.c:4942 Call Trace: lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691 __raw_write_lock include/linux/rwlock_api_smp.h:209 [inline] _raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300 __drop_extent_tree+0x3ac/0x660 fs/f2fs/extent_cache.c:1100 f2fs_drop_extent_tree+0x17/0x30 fs/f2fs/extent_cache.c:1116 f2fs_insert_range+0x2d5/0x3c0 fs/f2fs/file.c:1664 f2fs_fallocate+0x4e4/0x6d0 fs/f2fs/file.c:1838 vfs_fallocate+0x54b/0x6b0 fs/open.c:324 ksys_fallocate fs/open.c:347 [inline] __do_sys_fallocate fs/open.c:355 [inline] __se_sys_fallocate fs/open.c:353 [inline] __x64_sys_fallocate+0xbd/0x100 fs/open.c:353 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The root cause is race condition as below: - since it tries to remount rw filesystem, so that do_remount won't call sb_prepare_remount_readonly to block fallocate, there may be race condition in between remount and fallocate. - in f2fs_remount(), default_options() will reset mount option to default one, and then update it based on result of parse_options(), so there is a hole which race condition can happen. Thread A Thread B - f2fs_fill_super - parse_options - clear_opt(READ_EXTENT_CACHE) - f2fs_remount - default_options - set_opt(READ_EXTENT_CACHE) - f2fs_fallocate - f2fs_insert_range - f2fs_drop_extent_tree - __drop_extent_tree - __may_extent_tree - test_opt(READ_EXTENT_CACHE) return true - write_lock(&et->lock) access NULL pointer - parse_options - clear_opt(READ_EXTENT_CACHE)

In the Linux kernel, the following vulnerability has been resolved: mm/ksm: fix race with VMA iteration and mm_struct teardown exit_mmap() will tear down the VMAs and maple tree with the mmap_lock held in write mode. Ensure that the maple tree is still valid by checking ksm_test_exit() after taking the mmap_lock in read mode, but before the for_each_vma() iterator dereferences a destroyed maple tree. Since the maple tree is destroyed, the flags telling lockdep to check an external lock has been cleared. Skip the for_each_vma() iterator to avoid dereferencing a maple tree without the external lock flag, which would create a lockdep warning.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix hci_suspend_sync crash If hci_unregister_dev() frees the hci_dev object but hci_suspend_notifier may still be accessing it, it can cause the program to crash. Here's the call trace: <4>[102152.653246] Call Trace: <4>[102152.653254] hci_suspend_sync+0x109/0x301 [bluetooth] <4>[102152.653259] hci_suspend_dev+0x78/0xcd [bluetooth] <4>[102152.653263] hci_suspend_notifier+0x42/0x7a [bluetooth] <4>[102152.653268] notifier_call_chain+0x43/0x6b <4>[102152.653271] __blocking_notifier_call_chain+0x48/0x69 <4>[102152.653273] __pm_notifier_call_chain+0x22/0x39 <4>[102152.653276] pm_suspend+0x287/0x57c <4>[102152.653278] state_store+0xae/0xe5 <4>[102152.653281] kernfs_fop_write+0x109/0x173 <4>[102152.653284] __vfs_write+0x16f/0x1a2 <4>[102152.653287] ? selinux_file_permission+0xca/0x16f <4>[102152.653289] ? security_file_permission+0x36/0x109 <4>[102152.653291] vfs_write+0x114/0x21d <4>[102152.653293] __x64_sys_write+0x7b/0xdb <4>[102152.653296] do_syscall_64+0x59/0x194 <4>[102152.653299] entry_SYSCALL_64_after_hwframe+0x5c/0xc1 This patch holds the reference count of the hci_dev object while processing it in hci_suspend_notifier to avoid potential crash caused by the race condition.

In the Linux kernel, the following vulnerability has been resolved: tracing/synthetic: Fix races on freeing last_cmd Currently, the "last_cmd" variable can be accessed by multiple processes asynchronously when multiple users manipulate synthetic_events node at the same time, it could lead to use-after-free or double-free. This patch add "lastcmd_mutex" to prevent "last_cmd" from being accessed asynchronously. ================================================================ It's easy to reproduce in the KASAN environment by running the two scripts below in different shells. script 1: while : do echo -n -e '\x88' > /sys/kernel/tracing/synthetic_events done script 2: while : do echo -n -e '\xb0' > /sys/kernel/tracing/synthetic_events done ================================================================ double-free scenario: process A process B ------------------- --------------- 1.kstrdup last_cmd 2.free last_cmd 3.free last_cmd(double-free) ================================================================ use-after-free scenario: process A process B ------------------- --------------- 1.kstrdup last_cmd 2.free last_cmd 3.tracing_log_err(use-after-free) ================================================================ Appendix 1. KASAN report double-free: BUG: KASAN: double-free in kfree+0xdc/0x1d4 Free of addr ***** by task sh/4879 Call trace: ... kfree+0xdc/0x1d4 create_or_delete_synth_event+0x60/0x1e8 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... Allocated by task 4879: ... kstrdup+0x5c/0x98 create_or_delete_synth_event+0x6c/0x1e8 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... Freed by task 5464: ... kfree+0xdc/0x1d4 create_or_delete_synth_event+0x60/0x1e8 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... ================================================================ Appendix 2. KASAN report use-after-free: BUG: KASAN: use-after-free in strlen+0x5c/0x7c Read of size 1 at addr ***** by task sh/5483 sh: CPU: 7 PID: 5483 Comm: sh ... __asan_report_load1_noabort+0x34/0x44 strlen+0x5c/0x7c tracing_log_err+0x60/0x444 create_or_delete_synth_event+0xc4/0x204 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... Allocated by task 5483: ... kstrdup+0x5c/0x98 create_or_delete_synth_event+0x80/0x204 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ... Freed by task 5480: ... kfree+0xdc/0x1d4 create_or_delete_synth_event+0x74/0x204 trace_parse_run_command+0x2bc/0x4b8 synth_events_write+0x20/0x30 vfs_write+0x200/0x830 ...

In the Linux kernel, the following vulnerability has been resolved: bonding: fix oops during rmmod "rmmod bonding" causes an oops ever since commit cc317ea3d927 ("bonding: remove redundant NULL check in debugfs function"). Here are the relevant functions being called: bonding_exit() bond_destroy_debugfs() debugfs_remove_recursive(bonding_debug_root); bonding_debug_root = NULL; <--------- SET TO NULL HERE bond_netlink_fini() rtnl_link_unregister() __rtnl_link_unregister() unregister_netdevice_many_notify() bond_uninit() bond_debug_unregister() (commit removed check for bonding_debug_root == NULL) debugfs_remove() simple_recursive_removal() down_write() -> OOPS However, reverting the bad commit does not solve the problem completely because the original code contains a race that could cause the same oops, although it was much less likely to be triggered unintentionally: CPU1 rmmod bonding bonding_exit() bond_destroy_debugfs() debugfs_remove_recursive(bonding_debug_root); CPU2 echo -bond0 > /sys/class/net/bonding_masters bond_uninit() bond_debug_unregister() if (!bonding_debug_root) CPU1 bonding_debug_root = NULL; So do NOT revert the bad commit (since the removed checks were racy anyway), and instead change the order of actions taken during module removal. The same oops can also happen if there is an error during module init, so apply the same fix there.

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix deletion race condition System crash when using debug kernel due to link list corruption. The cause of the link list corruption is due to session deletion was allowed to queue up twice. Here's the internal trace that show the same port was allowed to double queue for deletion on different cpu. 20808683956 015 qla2xxx [0000:13:00.1]-e801:4: Scheduling sess ffff93ebf9306800 for deletion 50:06:0e:80:12:48:ff:50 fc4_type 1 20808683957 027 qla2xxx [0000:13:00.1]-e801:4: Scheduling sess ffff93ebf9306800 for deletion 50:06:0e:80:12:48:ff:50 fc4_type 1 Move the clearing/setting of deleted flag lock.

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix race issue between cpu buffer write and swap Warning happened in rb_end_commit() at code: if (RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing))) WARNING: CPU: 0 PID: 139 at kernel/trace/ring_buffer.c:3142 rb_commit+0x402/0x4a0 Call Trace: ring_buffer_unlock_commit+0x42/0x250 trace_buffer_unlock_commit_regs+0x3b/0x250 trace_event_buffer_commit+0xe5/0x440 trace_event_buffer_reserve+0x11c/0x150 trace_event_raw_event_sched_switch+0x23c/0x2c0 __traceiter_sched_switch+0x59/0x80 __schedule+0x72b/0x1580 schedule+0x92/0x120 worker_thread+0xa0/0x6f0 It is because the race between writing event into cpu buffer and swapping cpu buffer through file per_cpu/cpu0/snapshot: Write on CPU 0 Swap buffer by per_cpu/cpu0/snapshot on CPU 1 -------- -------- tracing_snapshot_write() [...] ring_buffer_lock_reserve() cpu_buffer = buffer->buffers[cpu]; // 1. Suppose find 'cpu_buffer_a'; [...] rb_reserve_next_event() [...] ring_buffer_swap_cpu() if (local_read(&cpu_buffer_a->committing)) goto out_dec; if (local_read(&cpu_buffer_b->committing)) goto out_dec; buffer_a->buffers[cpu] = cpu_buffer_b; buffer_b->buffers[cpu] = cpu_buffer_a; // 2. cpu_buffer has swapped here. rb_start_commit(cpu_buffer); if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) { // 3. This check passed due to 'cpu_buffer->buffer' [...] // has not changed here. return NULL; } cpu_buffer_b->buffer = buffer_a; cpu_buffer_a->buffer = buffer_b; [...] // 4. Reserve event from 'cpu_buffer_a'. ring_buffer_unlock_commit() [...] cpu_buffer = buffer->buffers[cpu]; // 5. Now find 'cpu_buffer_b' !!! rb_commit(cpu_buffer) rb_end_commit() // 6. WARN for the wrong 'committing' state !!! Based on above analysis, we can easily reproduce by following testcase: ``` bash #!/bin/bash dmesg -n 7 sysctl -w kernel.panic_on_warn=1 TR=/sys/kernel/tracing echo 7 > ${TR}/buffer_size_kb echo "sched:sched_switch" > ${TR}/set_event while [ true ]; do echo 1 > ${TR}/per_cpu/cpu0/snapshot done & while [ true ]; do echo 1 > ${TR}/per_cpu/cpu0/snapshot done & while [ true ]; do echo 1 > ${TR}/per_cpu/cpu0/snapshot done & ``` To fix it, IIUC, we can use smp_call_function_single() to do the swap on the target cpu where the buffer is located, so that above race would be avoided.

In the Linux kernel, the following vulnerability has been resolved: cxl/port: Fix delete_endpoint() vs parent unregistration race The CXL subsystem, at cxl_mem ->probe() time, establishes a lineage of ports (struct cxl_port objects) between an endpoint and the root of a CXL topology. Each port including the endpoint port is attached to the cxl_port driver. Given that setup, it follows that when either any port in that lineage goes through a cxl_port ->remove() event, or the memdev goes through a cxl_mem ->remove() event. The hierarchy below the removed port, or the entire hierarchy if the memdev is removed needs to come down. The delete_endpoint() callback is careful to check whether it is being called to tear down the hierarchy, or if it is only being called to teardown the memdev because an ancestor port is going through ->remove(). That care needs to take the device_lock() of the endpoint's parent. Which requires 2 bugs to be fixed: 1/ A reference on the parent is needed to prevent use-after-free scenarios like this signature: BUG: spinlock bad magic on CPU#0, kworker/u56:0/11 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230524-3.fc38 05/24/2023 Workqueue: cxl_port detach_memdev [cxl_core] RIP: 0010:spin_bug+0x65/0xa0 Call Trace: do_raw_spin_lock+0x69/0xa0 __mutex_lock+0x695/0xb80 delete_endpoint+0xad/0x150 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 detach_memdev+0x15/0x20 [cxl_core] process_one_work+0x1e3/0x4c0 worker_thread+0x1dd/0x3d0 2/ In the case of RCH topologies, the parent device that needs to be locked is not always @port->dev as returned by cxl_mem_find_port(), use endpoint->dev.parent instead.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix race condition in hci_cmd_sync_clear There is a potential race condition in hci_cmd_sync_work and hci_cmd_sync_clear, and could lead to use-after-free. For instance, hci_cmd_sync_work is added to the 'req_workqueue' after cancel_work_sync The entry of 'cmd_sync_work_list' may be freed in hci_cmd_sync_clear, and causing kernel panic when it is used in 'hci_cmd_sync_work'. Here's the call trace: dump_stack_lvl+0x49/0x63 print_report.cold+0x5e/0x5d3 ? hci_cmd_sync_work+0x282/0x320 kasan_report+0xaa/0x120 ? hci_cmd_sync_work+0x282/0x320 __asan_report_load8_noabort+0x14/0x20 hci_cmd_sync_work+0x282/0x320 process_one_work+0x77b/0x11c0 ? _raw_spin_lock_irq+0x8e/0xf0 worker_thread+0x544/0x1180 ? poll_idle+0x1e0/0x1e0 kthread+0x285/0x320 ? process_one_work+0x11c0/0x11c0 ? kthread_complete_and_exit+0x30/0x30 ret_from_fork+0x22/0x30 </TASK> Allocated by task 266: kasan_save_stack+0x26/0x50 __kasan_kmalloc+0xae/0xe0 kmem_cache_alloc_trace+0x191/0x350 hci_cmd_sync_queue+0x97/0x2b0 hci_update_passive_scan+0x176/0x1d0 le_conn_complete_evt+0x1b5/0x1a00 hci_le_conn_complete_evt+0x234/0x340 hci_le_meta_evt+0x231/0x4e0 hci_event_packet+0x4c5/0xf00 hci_rx_work+0x37d/0x880 process_one_work+0x77b/0x11c0 worker_thread+0x544/0x1180 kthread+0x285/0x320 ret_from_fork+0x22/0x30 Freed by task 269: kasan_save_stack+0x26/0x50 kasan_set_track+0x25/0x40 kasan_set_free_info+0x24/0x40 ____kasan_slab_free+0x176/0x1c0 __kasan_slab_free+0x12/0x20 slab_free_freelist_hook+0x95/0x1a0 kfree+0xba/0x2f0 hci_cmd_sync_clear+0x14c/0x210 hci_unregister_dev+0xff/0x440 vhci_release+0x7b/0xf0 __fput+0x1f3/0x970 ____fput+0xe/0x20 task_work_run+0xd4/0x160 do_exit+0x8b0/0x22a0 do_group_exit+0xba/0x2a0 get_signal+0x1e4a/0x25b0 arch_do_signal_or_restart+0x93/0x1f80 exit_to_user_mode_prepare+0xf5/0x1a0 syscall_exit_to_user_mode+0x26/0x50 ret_from_fork+0x15/0x30

In the Linux kernel, the following vulnerability has been resolved: net: fix data-races around sk->sk_forward_alloc Syzkaller reported this warning: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 16 at net/ipv4/af_inet.c:156 inet_sock_destruct+0x1c5/0x1e0 Modules linked in: CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc5 #26 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:inet_sock_destruct+0x1c5/0x1e0 Code: 24 12 4c 89 e2 5b 48 c7 c7 98 ec bb 82 41 5c e9 d1 18 17 ff 4c 89 e6 5b 48 c7 c7 d0 ec bb 82 41 5c e9 bf 18 17 ff 0f 0b eb 83 <0f> 0b eb 97 0f 0b eb 87 0f 0b e9 68 ff ff ff 66 66 2e 0f 1f 84 00 RSP: 0018:ffffc9000008bd90 EFLAGS: 00010206 RAX: 0000000000000300 RBX: ffff88810b172a90 RCX: 0000000000000007 RDX: 0000000000000002 RSI: 0000000000000300 RDI: ffff88810b172a00 RBP: ffff88810b172a00 R08: ffff888104273c00 R09: 0000000000100007 R10: 0000000000020000 R11: 0000000000000006 R12: ffff88810b172a00 R13: 0000000000000004 R14: 0000000000000000 R15: ffff888237c31f78 FS: 0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc63fecac8 CR3: 000000000342e000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __warn+0x88/0x130 ? inet_sock_destruct+0x1c5/0x1e0 ? report_bug+0x18e/0x1a0 ? handle_bug+0x53/0x90 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? inet_sock_destruct+0x1c5/0x1e0 __sk_destruct+0x2a/0x200 rcu_do_batch+0x1aa/0x530 ? rcu_do_batch+0x13b/0x530 rcu_core+0x159/0x2f0 handle_softirqs+0xd3/0x2b0 ? __pfx_smpboot_thread_fn+0x10/0x10 run_ksoftirqd+0x25/0x30 smpboot_thread_fn+0xdd/0x1d0 kthread+0xd3/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> ---[ end trace 0000000000000000 ]--- Its possible that two threads call tcp_v6_do_rcv()/sk_forward_alloc_add() concurrently when sk->sk_state == TCP_LISTEN with sk->sk_lock unlocked, which triggers a data-race around sk->sk_forward_alloc: tcp_v6_rcv tcp_v6_do_rcv skb_clone_and_charge_r sk_rmem_schedule __sk_mem_schedule sk_forward_alloc_add() skb_set_owner_r sk_mem_charge sk_forward_alloc_add() __kfree_skb skb_release_all skb_release_head_state sock_rfree sk_mem_uncharge sk_forward_alloc_add() sk_mem_reclaim // set local var reclaimable __sk_mem_reclaim sk_forward_alloc_add() In this syzkaller testcase, two threads call tcp_v6_do_rcv() with skb->truesize=768, the sk_forward_alloc changes like this: (cpu 1) | (cpu 2) | sk_forward_alloc ... | ... | 0 __sk_mem_schedule() | | +4096 = 4096 | __sk_mem_schedule() | +4096 = 8192 sk_mem_charge() | | -768 = 7424 | sk_mem_charge() | -768 = 6656 ... | ... | sk_mem_uncharge() | | +768 = 7424 reclaimable=7424 | | | sk_mem_uncharge() | +768 = 8192 | reclaimable=8192 | __sk_mem_reclaim() | | -4096 = 4096 | __sk_mem_reclaim() | -8192 = -4096 != 0 The skb_clone_and_charge_r() should not be called in tcp_v6_do_rcv() when sk->sk_state is TCP_LISTEN, it happens later in tcp_v6_syn_recv_sock(). Fix the same issue in dccp_v6_do_rcv().

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Fix racing issue between ufshcd_mcq_abort() and ISR If command timeout happens and cq complete IRQ is raised at the same time, ufshcd_mcq_abort clears lprb->cmd and a NULL pointer deref happens in the ISR. Error log: ufshcd_abort: Device abort task at tag 18 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000108 pc : [0xffffffe27ef867ac] scsi_dma_unmap+0xc/0x44 lr : [0xffffffe27f1b898c] ufshcd_release_scsi_cmd+0x24/0x114

In the Linux kernel, the following vulnerability has been resolved: workqueue: fix data race with the pwq->stats[] increment KCSAN has discovered a data race in kernel/workqueue.c:2598: [ 1863.554079] ================================================================== [ 1863.554118] BUG: KCSAN: data-race in process_one_work / process_one_work [ 1863.554142] write to 0xffff963d99d79998 of 8 bytes by task 5394 on cpu 27: [ 1863.554154] process_one_work (kernel/workqueue.c:2598) [ 1863.554166] worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2752) [ 1863.554177] kthread (kernel/kthread.c:389) [ 1863.554186] ret_from_fork (arch/x86/kernel/process.c:145) [ 1863.554197] ret_from_fork_asm (arch/x86/entry/entry_64.S:312) [ 1863.554213] read to 0xffff963d99d79998 of 8 bytes by task 5450 on cpu 12: [ 1863.554224] process_one_work (kernel/workqueue.c:2598) [ 1863.554235] worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2752) [ 1863.554247] kthread (kernel/kthread.c:389) [ 1863.554255] ret_from_fork (arch/x86/kernel/process.c:145) [ 1863.554266] ret_from_fork_asm (arch/x86/entry/entry_64.S:312) [ 1863.554280] value changed: 0x0000000000001766 -> 0x000000000000176a [ 1863.554295] Reported by Kernel Concurrency Sanitizer on: [ 1863.554303] CPU: 12 PID: 5450 Comm: kworker/u64:1 Tainted: G L 6.5.0-rc6+ #44 [ 1863.554314] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023 [ 1863.554322] Workqueue: btrfs-endio btrfs_end_bio_work [btrfs] [ 1863.554941] ================================================================== lockdep_invariant_state(true); → pwq->stats[PWQ_STAT_STARTED]++; trace_workqueue_execute_start(work); worker->current_func(work); Moving pwq->stats[PWQ_STAT_STARTED]++; before the line raw_spin_unlock_irq(&pool->lock); resolves the data race without performance penalty. KCSAN detected at least one additional data race: [ 157.834751] ================================================================== [ 157.834770] BUG: KCSAN: data-race in process_one_work / process_one_work [ 157.834793] write to 0xffff9934453f77a0 of 8 bytes by task 468 on cpu 29: [ 157.834804] process_one_work (/home/marvin/linux/kernel/linux_torvalds/kernel/workqueue.c:2606) [ 157.834815] worker_thread (/home/marvin/linux/kernel/linux_torvalds/./include/linux/list.h:292 /home/marvin/linux/kernel/linux_torvalds/kernel/workqueue.c:2752) [ 157.834826] kthread (/home/marvin/linux/kernel/linux_torvalds/kernel/kthread.c:389) [ 157.834834] ret_from_fork (/home/marvin/linux/kernel/linux_torvalds/arch/x86/kernel/process.c:145) [ 157.834845] ret_from_fork_asm (/home/marvin/linux/kernel/linux_torvalds/arch/x86/entry/entry_64.S:312) [ 157.834859] read to 0xffff9934453f77a0 of 8 bytes by task 214 on cpu 7: [ 157.834868] process_one_work (/home/marvin/linux/kernel/linux_torvalds/kernel/workqueue.c:2606) [ 157.834879] worker_thread (/home/marvin/linux/kernel/linux_torvalds/./include/linux/list.h:292 /home/marvin/linux/kernel/linux_torvalds/kernel/workqueue.c:2752) [ 157.834890] kthread (/home/marvin/linux/kernel/linux_torvalds/kernel/kthread.c:389) [ 157.834897] ret_from_fork (/home/marvin/linux/kernel/linux_torvalds/arch/x86/kernel/process.c:145) [ 157.834907] ret_from_fork_asm (/home/marvin/linux/kernel/linux_torvalds/arch/x86/entry/entry_64.S:312) [ 157.834920] value changed: 0x000000000000052a -> 0x0000000000000532 [ 157.834933] Reported by Kernel Concurrency Sanitizer on: [ 157.834941] CPU: 7 PID: 214 Comm: kworker/u64:2 Tainted: G L 6.5.0-rc7-kcsan-00169-g81eaf55a60fc #4 [ 157.834951] Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023 [ 157.834958] Workqueue: btrfs-endio btrfs_end_bio_work [btrfs] [ 157.835567] ================================================================== in code: trace_workqueue_execute_end(work, worker->current_func); → pwq->stats[PWQ_STAT_COM ---truncated---

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: fix race on port output assume the following setup on a single machine: 1. An openvswitch instance with one bridge and default flows 2. two network namespaces "server" and "client" 3. two ovs interfaces "server" and "client" on the bridge 4. for each ovs interface a veth pair with a matching name and 32 rx and tx queues 5. move the ends of the veth pairs to the respective network namespaces 6. assign ip addresses to each of the veth ends in the namespaces (needs to be the same subnet) 7. start some http server on the server network namespace 8. test if a client in the client namespace can reach the http server when following the actions below the host has a chance of getting a cpu stuck in a infinite loop: 1. send a large amount of parallel requests to the http server (around 3000 curls should work) 2. in parallel delete the network namespace (do not delete interfaces or stop the server, just kill the namespace) there is a low chance that this will cause the below kernel cpu stuck message. If this does not happen just retry. Below there is also the output of bpftrace for the functions mentioned in the output. The series of events happening here is: 1. the network namespace is deleted calling `unregister_netdevice_many_notify` somewhere in the process 2. this sets first `NETREG_UNREGISTERING` on both ends of the veth and then runs `synchronize_net` 3. it then calls `call_netdevice_notifiers` with `NETDEV_UNREGISTER` 4. this is then handled by `dp_device_event` which calls `ovs_netdev_detach_dev` (if a vport is found, which is the case for the veth interface attached to ovs) 5. this removes the rx_handlers of the device but does not prevent packages to be sent to the device 6. `dp_device_event` then queues the vport deletion to work in background as a ovs_lock is needed that we do not hold in the unregistration path 7. `unregister_netdevice_many_notify` continues to call `netdev_unregister_kobject` which sets `real_num_tx_queues` to 0 8. port deletion continues (but details are not relevant for this issue) 9. at some future point the background task deletes the vport If after 7. but before 9. a packet is send to the ovs vport (which is not deleted at this point in time) which forwards it to the `dev_queue_xmit` flow even though the device is unregistering. In `skb_tx_hash` (which is called in the `dev_queue_xmit`) path there is a while loop (if the packet has a rx_queue recorded) that is infinite if `dev->real_num_tx_queues` is zero. To prevent this from happening we update `do_output` to handle devices without carrier the same as if the device is not found (which would be the code path after 9. is done). Additionally we now produce a warning in `skb_tx_hash` if we will hit the infinite loop. bpftrace (first word is function name): __dev_queue_xmit server: real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1 netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1 dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 2, reg_state: 1 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 6, reg_state: 2 ovs_netdev_detach_dev server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, reg_state: 2 netdev_rx_handler_unregister server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 netdev_rx_handler_unregister ret server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2 dp_ ---truncated---

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix potential data race in rxrpc_wait_to_be_connected() Inside the loop in rxrpc_wait_to_be_connected() it checks call->error to see if it should exit the loop without first checking the call state. This is probably safe as if call->error is set, the call is dead anyway, but we should probably wait for the call state to have been set to completion first, lest it cause surprise on the way out. Fix this by only accessing call->error if the call is complete. We don't actually need to access the error inside the loop as we'll do that after. This caused the following report: BUG: KCSAN: data-race in rxrpc_send_data / rxrpc_set_call_completion write to 0xffff888159cf3c50 of 4 bytes by task 25673 on cpu 1: rxrpc_set_call_completion+0x71/0x1c0 net/rxrpc/call_state.c:22 rxrpc_send_data_packet+0xba9/0x1650 net/rxrpc/output.c:479 rxrpc_transmit_one+0x1e/0x130 net/rxrpc/output.c:714 rxrpc_decant_prepared_tx net/rxrpc/call_event.c:326 [inline] rxrpc_transmit_some_data+0x496/0x600 net/rxrpc/call_event.c:350 rxrpc_input_call_event+0x564/0x1220 net/rxrpc/call_event.c:464 rxrpc_io_thread+0x307/0x1d80 net/rxrpc/io_thread.c:461 kthread+0x1ac/0x1e0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 read to 0xffff888159cf3c50 of 4 bytes by task 25672 on cpu 0: rxrpc_send_data+0x29e/0x1950 net/rxrpc/sendmsg.c:296 rxrpc_do_sendmsg+0xb7a/0xc20 net/rxrpc/sendmsg.c:726 rxrpc_sendmsg+0x413/0x520 net/rxrpc/af_rxrpc.c:565 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0x375/0x4c0 net/socket.c:2501 ___sys_sendmsg net/socket.c:2555 [inline] __sys_sendmmsg+0x263/0x500 net/socket.c:2641 __do_sys_sendmmsg net/socket.c:2670 [inline] __se_sys_sendmmsg net/socket.c:2667 [inline] __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2667 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000000 -> 0xffffffea

In the Linux kernel, the following vulnerability has been resolved: tee: amdtee: fix race condition in amdtee_open_session There is a potential race condition in amdtee_open_session that may lead to use-after-free. For instance, in amdtee_open_session() after sess->sess_mask is set, and before setting: sess->session_info[i] = session_info; if amdtee_close_session() closes this same session, then 'sess' data structure will be released, causing kernel panic when 'sess' is accessed within amdtee_open_session(). The solution is to set the bit sess->sess_mask as the last step in amdtee_open_session().

In the Linux kernel, the following vulnerability has been resolved: Revert "xsk: Support redirect to any socket bound to the same umem" This reverts commit 2863d665ea41282379f108e4da6c8a2366ba66db. This patch introduced a potential kernel crash when multiple napi instances redirect to the same AF_XDP socket. By removing the queue_index check, it is possible for multiple napi instances to access the Rx ring at the same time, which will result in a corrupted ring state which can lead to a crash when flushing the rings in __xsk_flush(). This can happen when the linked list of sockets to flush gets corrupted by concurrent accesses. A quick and small fix is not possible, so let us revert this for now.

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: vsie: fix race during shadow creation Right now it is possible to see gmap->private being zero in kvm_s390_vsie_gmap_notifier resulting in a crash. This is due to the fact that we add gmap->private == kvm after creation: static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { [...] gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); if (IS_ERR(gmap)) return PTR_ERR(gmap); gmap->private = vcpu->kvm; Let children inherit the private field of the parent.

In the Linux kernel, the following vulnerability has been resolved: nvme: tcp: avoid race between queue_lock lock and destroy Commit 76d54bf20cdc ("nvme-tcp: don't access released socket during error recovery") added a mutex_lock() call for the queue->queue_lock in nvme_tcp_get_address(). However, the mutex_lock() races with mutex_destroy() in nvme_tcp_free_queue(), and causes the WARN below. DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: CPU: 3 PID: 34077 at kernel/locking/mutex.c:587 __mutex_lock+0xcf0/0x1220 Modules linked in: nvmet_tcp nvmet nvme_tcp nvme_fabrics iw_cm ib_cm ib_core pktcdvd nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables qrtr sunrpc ppdev 9pnet_virtio 9pnet pcspkr netfs parport_pc parport e1000 i2c_piix4 i2c_smbus loop fuse nfnetlink zram bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper xfs drm sym53c8xx floppy nvme scsi_transport_spi nvme_core nvme_auth serio_raw ata_generic pata_acpi dm_multipath qemu_fw_cfg [last unloaded: ib_uverbs] CPU: 3 UID: 0 PID: 34077 Comm: udisksd Not tainted 6.11.0-rc7 #319 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:__mutex_lock+0xcf0/0x1220 Code: 08 84 d2 0f 85 c8 04 00 00 8b 15 ef b6 c8 01 85 d2 0f 85 78 f4 ff ff 48 c7 c6 20 93 ee af 48 c7 c7 60 91 ee af e8 f0 a7 6d fd <0f> 0b e9 5e f4 ff ff 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 RSP: 0018:ffff88811305f760 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88812c652058 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffff88811305f8b0 R08: 0000000000000001 R09: ffffed1075c36341 R10: ffff8883ae1b1a0b R11: 0000000000010498 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff88812c652058 FS: 00007f9713ae4980(0000) GS:ffff8883ae180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcd78483c7c CR3: 0000000122c38000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __warn.cold+0x5b/0x1af ? __mutex_lock+0xcf0/0x1220 ? report_bug+0x1ec/0x390 ? handle_bug+0x3c/0x80 ? exc_invalid_op+0x13/0x40 ? asm_exc_invalid_op+0x16/0x20 ? __mutex_lock+0xcf0/0x1220 ? nvme_tcp_get_address+0xc2/0x1e0 [nvme_tcp] ? __pfx___mutex_lock+0x10/0x10 ? __lock_acquire+0xd6a/0x59e0 ? nvme_tcp_get_address+0xc2/0x1e0 [nvme_tcp] nvme_tcp_get_address+0xc2/0x1e0 [nvme_tcp] ? __pfx_nvme_tcp_get_address+0x10/0x10 [nvme_tcp] nvme_sysfs_show_address+0x81/0xc0 [nvme_core] dev_attr_show+0x42/0x80 ? __asan_memset+0x1f/0x40 sysfs_kf_seq_show+0x1f0/0x370 seq_read_iter+0x2cb/0x1130 ? rw_verify_area+0x3b1/0x590 ? __mutex_lock+0x433/0x1220 vfs_read+0x6a6/0xa20 ? lockdep_hardirqs_on+0x78/0x100 ? __pfx_vfs_read+0x10/0x10 ksys_read+0xf7/0x1d0 ? __pfx_ksys_read+0x10/0x10 ? __x64_sys_openat+0x105/0x1d0 do_syscall_64+0x93/0x180 ? lockdep_hardirqs_on_prepare+0x16d/0x400 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on+0x78/0x100 ? do_syscall_64+0x9f/0x180 ? __pfx_ksys_read+0x10/0x10 ? lockdep_hardirqs_on_prepare+0x16d/0x400 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on+0x78/0x100 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on_prepare+0x16d/0x400 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on+0x78/0x100 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on_prepare+0x16d/0x400 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on+0x78/0x100 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on_prepare+0x16d/0x400 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on+0x78/0x100 ? do_syscall_64+0x9f/0x180 ? do_syscall_64+0x9f/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f9713f55cfa Code: 55 48 89 e5 48 83 ec 20 48 89 55 e8 48 89 75 f0 89 7d f8 e8 e8 74 f8 ff 48 8b 55 e8 48 8b 75 f0 4 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: pmdomain: mediatek: fix race conditions with genpd If the power domains are registered first with genpd and *after that* the driver attempts to power them on in the probe sequence, then it is possible that a race condition occurs if genpd tries to power them on in the same time. The same is valid for powering them off before unregistering them from genpd. Attempt to fix race conditions by first removing the domains from genpd and *after that* powering down domains. Also first power up the domains and *after that* register them to genpd.

In the Linux kernel, the following vulnerability has been resolved: mm: fix zswap writeback race condition The zswap writeback mechanism can cause a race condition resulting in memory corruption, where a swapped out page gets swapped in with data that was written to a different page. The race unfolds like this: 1. a page with data A and swap offset X is stored in zswap 2. page A is removed off the LRU by zpool driver for writeback in zswap-shrink work, data for A is mapped by zpool driver 3. user space program faults and invalidates page entry A, offset X is considered free 4. kswapd stores page B at offset X in zswap (zswap could also be full, if so, page B would then be IOed to X, then skip step 5.) 5. entry A is replaced by B in tree->rbroot, this doesn't affect the local reference held by zswap-shrink work 6. zswap-shrink work writes back A at X, and frees zswap entry A 7. swapin of slot X brings A in memory instead of B The fix: Once the swap page cache has been allocated (case ZSWAP_SWAPCACHE_NEW), zswap-shrink work just checks that the local zswap_entry reference is still the same as the one in the tree. If it's not the same it means that it's either been invalidated or replaced, in both cases the writeback is aborted because the local entry contains stale data. Reproducer: I originally found this by running `stress` overnight to validate my work on the zswap writeback mechanism, it manifested after hours on my test machine. The key to make it happen is having zswap writebacks, so whatever setup pumps /sys/kernel/debug/zswap/written_back_pages should do the trick. In order to reproduce this faster on a vm, I setup a system with ~100M of available memory and a 500M swap file, then running `stress --vm 1 --vm-bytes 300000000 --vm-stride 4000` makes it happen in matter of tens of minutes. One can speed things up even more by swinging /sys/module/zswap/parameters/max_pool_percent up and down between, say, 20 and 1; this makes it reproduce in tens of seconds. It's crucial to set `--vm-stride` to something other than 4096 otherwise `stress` won't realize that memory has been corrupted because all pages would have the same data.

In the Linux kernel, the following vulnerability has been resolved: l2tp: close all race conditions in l2tp_tunnel_register() The code in l2tp_tunnel_register() is racy in several ways: 1. It modifies the tunnel socket _after_ publishing it. 2. It calls setup_udp_tunnel_sock() on an existing socket without locking. 3. It changes sock lock class on fly, which triggers many syzbot reports. This patch amends all of them by moving socket initialization code before publishing and under sock lock. As suggested by Jakub, the l2tp lockdep class is not necessary as we can just switch to bh_lock_sock_nested().

In the Linux kernel, the following vulnerability has been resolved: firmware: arm_scmi: Check mailbox/SMT channel for consistency On reception of a completion interrupt the shared memory area is accessed to retrieve the message header at first and then, if the message sequence number identifies a transaction which is still pending, the related payload is fetched too. When an SCMI command times out the channel ownership remains with the platform until eventually a late reply is received and, as a consequence, any further transmission attempt remains pending, waiting for the channel to be relinquished by the platform. Once that late reply is received the channel ownership is given back to the agent and any pending request is then allowed to proceed and overwrite the SMT area of the just delivered late reply; then the wait for the reply to the new request starts. It has been observed that the spurious IRQ related to the late reply can be wrongly associated with the freshly enqueued request: when that happens the SCMI stack in-flight lookup procedure is fooled by the fact that the message header now present in the SMT area is related to the new pending transaction, even though the real reply has still to arrive. This race-condition on the A2P channel can be detected by looking at the channel status bits: a genuine reply from the platform will have set the channel free bit before triggering the completion IRQ. Add a consistency check to validate such condition in the A2P ISR.

In the Linux kernel, the following vulnerability has been resolved: rcu/kvfree: Fix data-race in __mod_timer / kvfree_call_rcu KCSAN reports a data race when access the krcp->monitor_work.timer.expires variable in the schedule_delayed_monitor_work() function: <snip> BUG: KCSAN: data-race in __mod_timer / kvfree_call_rcu read to 0xffff888237d1cce8 of 8 bytes by task 10149 on cpu 1: schedule_delayed_monitor_work kernel/rcu/tree.c:3520 [inline] kvfree_call_rcu+0x3b8/0x510 kernel/rcu/tree.c:3839 trie_update_elem+0x47c/0x620 kernel/bpf/lpm_trie.c:441 bpf_map_update_value+0x324/0x350 kernel/bpf/syscall.c:203 generic_map_update_batch+0x401/0x520 kernel/bpf/syscall.c:1849 bpf_map_do_batch+0x28c/0x3f0 kernel/bpf/syscall.c:5143 __sys_bpf+0x2e5/0x7a0 __do_sys_bpf kernel/bpf/syscall.c:5741 [inline] __se_sys_bpf kernel/bpf/syscall.c:5739 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5739 x64_sys_call+0x2625/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f write to 0xffff888237d1cce8 of 8 bytes by task 56 on cpu 0: __mod_timer+0x578/0x7f0 kernel/time/timer.c:1173 add_timer_global+0x51/0x70 kernel/time/timer.c:1330 __queue_delayed_work+0x127/0x1a0 kernel/workqueue.c:2523 queue_delayed_work_on+0xdf/0x190 kernel/workqueue.c:2552 queue_delayed_work include/linux/workqueue.h:677 [inline] schedule_delayed_monitor_work kernel/rcu/tree.c:3525 [inline] kfree_rcu_monitor+0x5e8/0x660 kernel/rcu/tree.c:3643 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391 kthread+0x1d1/0x210 kernel/kthread.c:389 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 56 Comm: kworker/u8:4 Not tainted 6.12.0-rc2-syzkaller-00050-g5b7c893ed5ed #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound kfree_rcu_monitor <snip> kfree_rcu_monitor() rearms the work if a "krcp" has to be still offloaded and this is done without holding krcp->lock, whereas the kvfree_call_rcu() holds it. Fix it by acquiring the "krcp->lock" for kfree_rcu_monitor() so both functions do not race anymore.

In the Linux kernel, the following vulnerability has been resolved: spi: Fix null dereference on suspend A race condition exists where a synchronous (noqueue) transfer can be active during a system suspend. This can cause a null pointer dereference exception to occur when the system resumes. Example order of events leading to the exception: 1. spi_sync() calls __spi_transfer_message_noqueue() which sets ctlr->cur_msg 2. Spi transfer begins via spi_transfer_one_message() 3. System is suspended interrupting the transfer context 4. System is resumed 6. spi_controller_resume() calls spi_start_queue() which resets cur_msg to NULL 7. Spi transfer context resumes and spi_finalize_current_message() is called which dereferences cur_msg (which is now NULL) Wait for synchronous transfers to complete before suspending by acquiring the bus mutex and setting/checking a suspend flag.

In the Linux kernel, the following vulnerability has been resolved: power: supply: bq25890: Fix external_power_changed race bq25890_charger_external_power_changed() dereferences bq->charger, which gets sets in bq25890_power_supply_init() like this: bq->charger = devm_power_supply_register(bq->dev, &bq->desc, &psy_cfg); As soon as devm_power_supply_register() has called device_add() the external_power_changed callback can get called. So there is a window where bq25890_charger_external_power_changed() may get called while bq->charger has not been set yet leading to a NULL pointer dereference. This race hits during boot sometimes on a Lenovo Yoga Book 1 yb1-x90f when the cht_wcove_pwrsrc (extcon) power_supply is done with detecting the connected charger-type which happens to exactly hit the small window: BUG: kernel NULL pointer dereference, address: 0000000000000018 <snip> RIP: 0010:__power_supply_is_supplied_by+0xb/0xb0 <snip> Call Trace: <TASK> __power_supply_get_supplier_property+0x19/0x50 class_for_each_device+0xb1/0xe0 power_supply_get_property_from_supplier+0x2e/0x50 bq25890_charger_external_power_changed+0x38/0x1b0 [bq25890_charger] __power_supply_changed_work+0x30/0x40 class_for_each_device+0xb1/0xe0 power_supply_changed_work+0x5f/0xe0 <snip> Fixing this is easy. The external_power_changed callback gets passed the power_supply which will eventually get stored in bq->charger, so bq25890_charger_external_power_changed() can simply directly use the passed in psy argument which is always valid.

In the Linux kernel, the following vulnerability has been resolved: powerpc/64s/interrupt: Fix interrupt exit race with security mitigation switch The RFI and STF security mitigation options can flip the interrupt_exit_not_reentrant static branch condition concurrently with the interrupt exit code which tests that branch. Interrupt exit tests this condition to set MSR[EE|RI] for exit, then again in the case a soft-masked interrupt is found pending, to recover the MSR so the interrupt can be replayed before attempting to exit again. If the condition changes between these two tests, the MSR and irq soft-mask state will become corrupted, leading to warnings and possible crashes. For example, if the branch is initially true then false, MSR[EE] will be 0 but PACA_IRQ_HARD_DIS clear and EE may not get enabled, leading to warnings in irq_64.c.