An issue found in linux-kernel that leads to a race condition in rose_connect(). The rose driver uses rose_neigh->use to represent how many objects are using the rose_neigh. When a user wants to delete a rose_route via rose_ioctl(), the rose driver calls rose_del_node() and removes neighbours only if their “count” and “use” are zero.

Race condition in drivers/tty/n_hdlc.c in the Linux kernel through 4.10.1 allows local users to gain privileges or cause a denial of service (double free) by setting the HDLC line discipline.

A null pointer dereference flaw was found in the nft_inner.c functionality of netfilter in the Linux kernel. This issue could allow a local user to crash the system or escalate their privileges on the system.

A use-after-free exists in drivers/tee/tee_shm.c in the TEE subsystem in the Linux kernel through 5.15.11. This occurs because of a race condition in tee_shm_get_from_id during an attempt to free a shared memory object.

The raw_sendmsg() function in net/ipv4/raw.c in the Linux kernel through 4.14.6 has a race condition in inet->hdrincl that leads to uninitialized stack pointer usage; this allows a local user to execute code and gain privileges.

A flaw was found in the way the dumpable flag setting was handled when certain SUID binaries executed its descendants. The prerequisite is a SUID binary that sets real UID equal to effective UID, and real GID equal to effective GID. The descendant will then have a dumpable value set to 1. As a result, if the descendant process crashes and core_pattern is set to a relative value, its core dump is stored in the current directory with uid:gid permissions. An unprivileged local user with eligible root SUID binary could use this flaw to place core dumps into root-owned directories, potentially resulting in escalation of privileges.

The driver_override implementation in drivers/base/platform.c in the Linux kernel before 4.12.1 allows local users to gain privileges by leveraging a race condition between a read operation and a store operation that involve different overrides.

Multiple race conditions in fs/pipe.c in the Linux kernel before 2.6.32-rc6 allow local users to cause a denial of service (NULL pointer dereference and system crash) or gain privileges by attempting to open an anonymous pipe via a /proc/*/fd/ pathname.

Linux kernel: Exploitable memory corruption due to UFO to non-UFO path switch. When building a UFO packet with MSG_MORE __ip_append_data() calls ip_ufo_append_data() to append. However in between two send() calls, the append path can be switched from UFO to non-UFO one, which leads to a memory corruption. In case UFO packet lengths exceeds MTU, copy = maxfraglen - skb->len becomes negative on the non-UFO path and the branch to allocate new skb is taken. This triggers fragmentation and computation of fraggap = skb_prev->len - maxfraglen. Fraggap can exceed MTU, causing copy = datalen - transhdrlen - fraggap to become negative. Subsequently skb_copy_and_csum_bits() writes out-of-bounds. A similar issue is present in IPv6 code. The bug was introduced in e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach") on Oct 18 2005.

A vulnerability in the shared library loading mechanism of Cisco AnyConnect Secure Mobility Client for Linux and Mac OS could allow an authenticated, local attacker to perform a shared library hijacking attack on an affected device if the VPN Posture (HostScan) Module is installed on the AnyConnect client. This vulnerability is due to a race condition in the signature verification process for shared library files that are loaded on an affected device. An attacker could exploit this vulnerability by sending a series of crafted interprocess communication (IPC) messages to the AnyConnect process. A successful exploit could allow the attacker to execute arbitrary code on the affected device with root privileges. To exploit this vulnerability, the attacker must have a valid account on the system.

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel 5.11.15. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of eBPF programs. The issue results from the lack of proper validation of user-supplied eBPF programs prior to executing them. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel. Was ZDI-CAN-13661.

kernel/events/core.c in the performance subsystem in the Linux kernel before 4.0 mismanages locks during certain migrations, which allows local users to gain privileges via a crafted application, aka Android internal bug 31095224.

kernel/events/core.c in the performance subsystem in the Linux kernel before 4.0 mismanages locks during certain migrations, which allows local users to gain privileges via a crafted application, aka Android internal bug 30955111.

A local privilege escalation was discovered in the Linux kernel before 5.10.13. Multiple race conditions in the AF_VSOCK implementation are caused by wrong locking in net/vmw_vsock/af_vsock.c. The race conditions were implicitly introduced in the commits that added VSOCK multi-transport support.

Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect handling of a copy-on-write (COW) feature to write to a read-only memory mapping, as exploited in the wild in October 2016, aka "Dirty COW."

Heap-based buffer overflow in drivers/net/macsec.c in the MACsec module in the Linux kernel through 4.10.12 allows attackers to cause a denial of service or possibly have unspecified other impact by leveraging the use of a MAX_SKB_FRAGS+1 size in conjunction with the NETIF_F_FRAGLIST feature, leading to an error in the skb_to_sgvec function.

The BPF subsystem in the Linux kernel before 4.5.5 mishandles reference counts, which allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a crafted application on (1) a system with more than 32 Gb of memory, related to the program reference count or (2) a 1 Tb system, related to the map reference count.

A TOCTOU mismatch in the NFS client code in the Linux kernel before 5.8.3 could be used by local attackers to corrupt memory or possibly have unspecified other impact because a size check is in fs/nfs/nfs4proc.c instead of fs/nfs/nfs4xdr.c, aka CID-b4487b935452.

.A flaw was found in the CAN BCM networking protocol in the Linux kernel, where a local attacker can abuse a flaw in the CAN subsystem to corrupt memory, crash the system or escalate privileges. This race condition in net/can/bcm.c in the Linux kernel allows for local privilege escalation to root.

A flaw was found in Linux Kernel because access to the global variable fg_console is not properly synchronized leading to a use after free in con_font_op.

The msm_ipc_router_bind_control_port function in net/ipc_router/ipc_router_core.c in the IPC router kernel module for the Linux kernel 3.x, as used in Qualcomm Innovation Center (QuIC) Android contributions for MSM devices and other products, does not verify that a port is a client port, which allows attackers to gain privileges or cause a denial of service (race condition and list corruption) by making many BIND_CONTROL_PORT ioctl calls.

A double free bug in packet_set_ring() in net/packet/af_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny service. We recommend upgrading kernel past the effected versions or rebuilding past ec6af094ea28f0f2dda1a6a33b14cd57e36a9755

The networking implementation in the Linux kernel through 4.3.3, as used in Android and other products, does not validate protocol identifiers for certain protocol families, which allows local users to cause a denial of service (NULL function pointer dereference and system crash) or possibly gain privileges by leveraging CLONE_NEWUSER support to execute a crafted SOCK_RAW application.

A possible unauthorized memory access flaw was found in the Linux kernel's cpu_entry_area mapping of X86 CPU data to memory, where a user may guess the location of exception stacks or other important data. Based on the previous CVE-2023-0597, the 'Randomize per-cpu entry area' feature was implemented in /arch/x86/mm/cpu_entry_area.c, which works through the init_cea_offsets() function when KASLR is enabled. However, despite this feature, there is still a risk of per-cpu entry area leaks. This issue could allow a local user to gain access to some important data with memory in an expected location and potentially escalate their privileges on the system.

In the Linux kernel, the following vulnerability has been resolved: mm/mremap: fix move_normal_pmd/retract_page_tables race In mremap(), move_page_tables() looks at the type of the PMD entry and the specified address range to figure out by which method the next chunk of page table entries should be moved. At that point, the mmap_lock is held in write mode, but no rmap locks are held yet. For PMD entries that point to page tables and are fully covered by the source address range, move_pgt_entry(NORMAL_PMD, ...) is called, which first takes rmap locks, then does move_normal_pmd(). move_normal_pmd() takes the necessary page table locks at source and destination, then moves an entire page table from the source to the destination. The problem is: The rmap locks, which protect against concurrent page table removal by retract_page_tables() in the THP code, are only taken after the PMD entry has been read and it has been decided how to move it. So we can race as follows (with two processes that have mappings of the same tmpfs file that is stored on a tmpfs mount with huge=advise); note that process A accesses page tables through the MM while process B does it through the file rmap: process A process B ========= ========= mremap mremap_to move_vma move_page_tables get_old_pmd alloc_new_pmd *** PREEMPT *** madvise(MADV_COLLAPSE) do_madvise madvise_walk_vmas madvise_vma_behavior madvise_collapse hpage_collapse_scan_file collapse_file retract_page_tables i_mmap_lock_read(mapping) pmdp_collapse_flush i_mmap_unlock_read(mapping) move_pgt_entry(NORMAL_PMD, ...) take_rmap_locks move_normal_pmd drop_rmap_locks When this happens, move_normal_pmd() can end up creating bogus PMD entries in the line `pmd_populate(mm, new_pmd, pmd_pgtable(pmd))`. The effect depends on arch-specific and machine-specific details; on x86, you can end up with physical page 0 mapped as a page table, which is likely exploitable for user->kernel privilege escalation. Fix the race by letting process B recheck that the PMD still points to a page table after the rmap locks have been taken. Otherwise, we bail and let the caller fall back to the PTE-level copying path, which will then bail immediately at the pmd_none() check. Bug reachability: Reaching this bug requires that you can create shmem/file THP mappings - anonymous THP uses different code that doesn't zap stuff under rmap locks. File THP is gated on an experimental config flag (CONFIG_READ_ONLY_THP_FOR_FS), so on normal distro kernels you need shmem THP to hit this bug. As far as I know, getting shmem THP normally requires that you can mount your own tmpfs with the right mount flags, which would require creating your own user+mount namespace; though I don't know if some distros maybe enable shmem THP by default or something like that. Bug impact: This issue can likely be used for user->kernel privilege escalation when it is reachable.

In the Linux kernel, the following vulnerability has been resolved: net: phylink: add lock for serializing concurrent pl->phydev writes with resolver Currently phylink_resolve() protects itself against concurrent phylink_bringup_phy() or phylink_disconnect_phy() calls which modify pl->phydev by relying on pl->state_mutex. The problem is that in phylink_resolve(), pl->state_mutex is in a lock inversion state with pl->phydev->lock. So pl->phydev->lock needs to be acquired prior to pl->state_mutex. But that requires dereferencing pl->phydev in the first place, and without pl->state_mutex, that is racy. Hence the reason for the extra lock. Currently it is redundant, but it will serve a functional purpose once mutex_lock(&phy->lock) will be moved outside of the mutex_lock(&pl->state_mutex) section. Another alternative considered would have been to let phylink_resolve() acquire the rtnl_mutex, which is also held when phylink_bringup_phy() and phylink_disconnect_phy() are called. But since phylink_disconnect_phy() runs under rtnl_lock(), it would deadlock with phylink_resolve() when calling flush_work(&pl->resolve). Additionally, it would have been undesirable because it would have unnecessarily blocked many other call paths as well in the entire kernel, so the smaller-scoped lock was preferred.

In the Linux kernel, the following vulnerability has been resolved: btrfs: qgroup: fix race between quota disable and quota rescan ioctl There's a race between a task disabling quotas and another running the rescan ioctl that can result in a use-after-free of qgroup records from the fs_info->qgroup_tree rbtree. This happens as follows: 1) Task A enters btrfs_ioctl_quota_rescan() -> btrfs_qgroup_rescan(); 2) Task B enters btrfs_quota_disable() and calls btrfs_qgroup_wait_for_completion(), which does nothing because at that point fs_info->qgroup_rescan_running is false (it wasn't set yet by task A); 3) Task B calls btrfs_free_qgroup_config() which starts freeing qgroups from fs_info->qgroup_tree without taking the lock fs_info->qgroup_lock; 4) Task A enters qgroup_rescan_zero_tracking() which starts iterating the fs_info->qgroup_tree tree while holding fs_info->qgroup_lock, but task B is freeing qgroup records from that tree without holding the lock, resulting in a use-after-free. Fix this by taking fs_info->qgroup_lock at btrfs_free_qgroup_config(). Also at btrfs_qgroup_rescan() don't start the rescan worker if quotas were already disabled.

In the Linux kernel, the following vulnerability has been resolved: VMCI: fix race between vmci_host_setup_notify and vmci_ctx_unset_notify During our test, it is found that a warning can be trigger in try_grab_folio as follow: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1678 at mm/gup.c:147 try_grab_folio+0x106/0x130 Modules linked in: CPU: 0 UID: 0 PID: 1678 Comm: syz.3.31 Not tainted 6.15.0-rc5 #163 PREEMPT(undef) RIP: 0010:try_grab_folio+0x106/0x130 Call Trace: <TASK> follow_huge_pmd+0x240/0x8e0 follow_pmd_mask.constprop.0.isra.0+0x40b/0x5c0 follow_pud_mask.constprop.0.isra.0+0x14a/0x170 follow_page_mask+0x1c2/0x1f0 __get_user_pages+0x176/0x950 __gup_longterm_locked+0x15b/0x1060 ? gup_fast+0x120/0x1f0 gup_fast_fallback+0x17e/0x230 get_user_pages_fast+0x5f/0x80 vmci_host_unlocked_ioctl+0x21c/0xf80 RIP: 0033:0x54d2cd ---[ end trace 0000000000000000 ]--- Digging into the source, context->notify_page may init by get_user_pages_fast and can be seen in vmci_ctx_unset_notify which will try to put_page. However get_user_pages_fast is not finished here and lead to following try_grab_folio warning. The race condition is shown as follow: cpu0 cpu1 vmci_host_do_set_notify vmci_host_setup_notify get_user_pages_fast(uva, 1, FOLL_WRITE, &context->notify_page); lockless_pages_from_mm gup_pgd_range gup_huge_pmd // update &context->notify_page vmci_host_do_set_notify vmci_ctx_unset_notify notify_page = context->notify_page; if (notify_page) put_page(notify_page); // page is freed __gup_longterm_locked __get_user_pages follow_trans_huge_pmd try_grab_folio // warn here To slove this, use local variable page to make notify_page can be seen after finish get_user_pages_fast.

In the Linux kernel, the following vulnerability has been resolved: net_sched: red: fix a race in __red_change() Gerrard Tai reported a race condition in RED, whenever SFQ perturb timer fires at the wrong time. The race is as follows: CPU 0 CPU 1 [1]: lock root [2]: qdisc_tree_flush_backlog() [3]: unlock root | | [5]: lock root | [6]: rehash | [7]: qdisc_tree_reduce_backlog() | [4]: qdisc_put() This can be abused to underflow a parent's qlen. Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog() should fix the race, because all packets will be purged from the qdisc before releasing the lock.

In the Linux kernel, the following vulnerability has been resolved: net_sched: drr: Fix double list add in class with netem as child qdisc As described in Gerrard's report [1], there are use cases where a netem child qdisc will make the parent qdisc's enqueue callback reentrant. In the case of drr, there won't be a UAF, but the code will add the same classifier to the list twice, which will cause memory corruption. In addition to checking for qlen being zero, this patch checks whether the class was already added to the active_list (cl_is_active) before adding to the list to cover for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

In the Linux kernel, the following vulnerability has been resolved: net_sched: ets: fix a race in ets_qdisc_change() Gerrard Tai reported a race condition in ETS, whenever SFQ perturb timer fires at the wrong time. The race is as follows: CPU 0 CPU 1 [1]: lock root [2]: qdisc_tree_flush_backlog() [3]: unlock root | | [5]: lock root | [6]: rehash | [7]: qdisc_tree_reduce_backlog() | [4]: qdisc_put() This can be abused to underflow a parent's qlen. Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog() should fix the race, because all packets will be purged from the qdisc before releasing the lock.

NVIDIA Resiliency Extension for Linux contains a vulnerability in the checkpointing core, where an attacker may cause a race condition. A successful exploit of this vulnerability might lead to information disclosure, data tampering, denial of service, or escalation of privileges.

do_tls_getsockopt in net/tls/tls_main.c in the Linux kernel through 6.2.6 lacks a lock_sock call, leading to a race condition (with a resultant use-after-free or NULL pointer dereference).

In Docker Desktop before v4.29.0, an attacker who has gained access to the Docker Desktop VM through a container breakout can further escape to the host by passing extensions and dashboard related IPC messages. Docker Desktop v4.29.0 https://docs.docker.com/desktop/release-notes/#4290 fixes the issue on MacOS, Linux and Windows with Hyper-V backend. As exploitation requires "Allow only extensions distributed through the Docker Marketplace" to be disabled, Docker Desktop  v4.31.0 https://docs.docker.com/desktop/release-notes/#4310  additionally changes the default configuration to enable this setting by default.

In the Linux kernel, the following vulnerability has been resolved: drm/dp_mst: Fix resetting msg rx state after topology removal If the MST topology is removed during the reception of an MST down reply or MST up request sideband message, the drm_dp_mst_topology_mgr::up_req_recv/down_rep_recv states could be reset from one thread via drm_dp_mst_topology_mgr_set_mst(false), racing with the reading/parsing of the message from another thread via drm_dp_mst_handle_down_rep() or drm_dp_mst_handle_up_req(). The race is possible since the reader/parser doesn't hold any lock while accessing the reception state. This in turn can lead to a memory corruption in the reader/parser as described by commit bd2fccac61b4 ("drm/dp_mst: Fix MST sideband message body length check"). Fix the above by resetting the message reception state if needed before reading/parsing a message. Another solution would be to hold the drm_dp_mst_topology_mgr::lock for the whole duration of the message reception/parsing in drm_dp_mst_handle_down_rep() and drm_dp_mst_handle_up_req(), however this would require a bigger change. Since the fix is also needed for stable, opting for the simpler solution in this patch.

A race condition was found in the Linux kernel's RxRPC network protocol, within the processing of RxRPC bundles. This issue results from the lack of proper locking when performing operations on an object. This may allow an attacker to escalate privileges and execute arbitrary code in the context of the kernel.

A time-of-check to time-of-use issue exists in io_uring subsystem's IORING_OP_CLOSE operation in the Linux kernel's versions 5.6 - 5.11 (inclusive), which allows a local user to elevate their privileges to root. Introduced in b5dba59e0cf7e2cc4d3b3b1ac5fe81ddf21959eb, patched in 9eac1904d3364254d622bf2c771c4f85cd435fc2, backported to stable in 788d0824269bef539fe31a785b1517882eafed93.

In the Linux kernel, pick_next_rt_entity() may return a type confused entry, not detected by the BUG_ON condition, as the confused entry will not be NULL, but list_head.The buggy error condition would lead to a type confused entry with the list head,which would then be used as a type confused sched_rt_entity,causing memory corruption.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix warning in ext4_iomap_begin as race between bmap and write We got issue as follows: ------------[ cut here ]------------ WARNING: CPU: 3 PID: 9310 at fs/ext4/inode.c:3441 ext4_iomap_begin+0x182/0x5d0 RIP: 0010:ext4_iomap_begin+0x182/0x5d0 RSP: 0018:ffff88812460fa08 EFLAGS: 00010293 RAX: ffff88811f168000 RBX: 0000000000000000 RCX: ffffffff97793c12 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: ffff88812c669160 R08: ffff88811f168000 R09: ffffed10258cd20f R10: ffff88812c669077 R11: ffffed10258cd20e R12: 0000000000000001 R13: 00000000000000a4 R14: 000000000000000c R15: ffff88812c6691ee FS: 00007fd0d6ff3740(0000) GS:ffff8883af180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd0d6dda290 CR3: 0000000104a62000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: iomap_apply+0x119/0x570 iomap_bmap+0x124/0x150 ext4_bmap+0x14f/0x250 bmap+0x55/0x80 do_vfs_ioctl+0x952/0xbd0 __x64_sys_ioctl+0xc6/0x170 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Above issue may happen as follows: bmap write bmap ext4_bmap iomap_bmap ext4_iomap_begin ext4_file_write_iter ext4_buffered_write_iter generic_perform_write ext4_da_write_begin ext4_da_write_inline_data_begin ext4_prepare_inline_data ext4_create_inline_data ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA); if (WARN_ON_ONCE(ext4_has_inline_data(inode))) ->trigger bug_on To solved above issue hold inode lock in ext4_bamp.

In the Linux kernel, the following vulnerability has been resolved: net: do not delay dst_entries_add() in dst_release() dst_entries_add() uses per-cpu data that might be freed at netns dismantle from ip6_route_net_exit() calling dst_entries_destroy() Before ip6_route_net_exit() can be called, we release all the dsts associated with this netns, via calls to dst_release(), which waits an rcu grace period before calling dst_destroy() dst_entries_add() use in dst_destroy() is racy, because dst_entries_destroy() could have been called already. Decrementing the number of dsts must happen sooner. Notes: 1) in CONFIG_XFRM case, dst_destroy() can call dst_release_immediate(child), this might also cause UAF if the child does not have DST_NOCOUNT set. IPSEC maintainers might take a look and see how to address this. 2) There is also discussion about removing this count of dst, which might happen in future kernels.

In the Linux kernel, the following vulnerability has been resolved: arm64/sve: Discard stale CPU state when handling SVE traps The logic for handling SVE traps manipulates saved FPSIMD/SVE state incorrectly, and a race with preemption can result in a task having TIF_SVE set and TIF_FOREIGN_FPSTATE clear even though the live CPU state is stale (e.g. with SVE traps enabled). This has been observed to result in warnings from do_sve_acc() where SVE traps are not expected while TIF_SVE is set: | if (test_and_set_thread_flag(TIF_SVE)) | WARN_ON(1); /* SVE access shouldn't have trapped */ Warnings of this form have been reported intermittently, e.g. https://lore.kernel.org/linux-arm-kernel/CA+G9fYtEGe_DhY2Ms7+L7NKsLYUomGsgqpdBj+QwDLeSg=JhGg@mail.gmail.com/ https://lore.kernel.org/linux-arm-kernel/000000000000511e9a060ce5a45c@google.com/ The race can occur when the SVE trap handler is preempted before and after manipulating the saved FPSIMD/SVE state, starting and ending on the same CPU, e.g. | void do_sve_acc(unsigned long esr, struct pt_regs *regs) | { | // Trap on CPU 0 with TIF_SVE clear, SVE traps enabled | // task->fpsimd_cpu is 0. | // per_cpu_ptr(&fpsimd_last_state, 0) is task. | | ... | | // Preempted; migrated from CPU 0 to CPU 1. | // TIF_FOREIGN_FPSTATE is set. | | get_cpu_fpsimd_context(); | | if (test_and_set_thread_flag(TIF_SVE)) | WARN_ON(1); /* SVE access shouldn't have trapped */ | | sve_init_regs() { | if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) { | ... | } else { | fpsimd_to_sve(current); | current->thread.fp_type = FP_STATE_SVE; | } | } | | put_cpu_fpsimd_context(); | | // Preempted; migrated from CPU 1 to CPU 0. | // task->fpsimd_cpu is still 0 | // If per_cpu_ptr(&fpsimd_last_state, 0) is still task then: | // - Stale HW state is reused (with SVE traps enabled) | // - TIF_FOREIGN_FPSTATE is cleared | // - A return to userspace skips HW state restore | } Fix the case where the state is not live and TIF_FOREIGN_FPSTATE is set by calling fpsimd_flush_task_state() to detach from the saved CPU state. This ensures that a subsequent context switch will not reuse the stale CPU state, and will instead set TIF_FOREIGN_FPSTATE, forcing the new state to be reloaded from memory prior to a return to userspace.

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlegacy: Clear stale interrupts before resuming device iwl4965 fails upon resume from hibernation on my laptop. The reason seems to be a stale interrupt which isn't being cleared out before interrupts are enabled. We end up with a race beween the resume trying to bring things back up, and the restart work (queued form the interrupt handler) trying to bring things down. Eventually the whole thing blows up. Fix the problem by clearing out any stale interrupts before interrupts get enabled during resume. Here's a debug log of the indicent: [ 12.042589] ieee80211 phy0: il_isr ISR inta 0x00000080, enabled 0xaa00008b, fh 0x00000000 [ 12.042625] ieee80211 phy0: il4965_irq_tasklet inta 0x00000080, enabled 0x00000000, fh 0x00000000 [ 12.042651] iwl4965 0000:10:00.0: RF_KILL bit toggled to enable radio. [ 12.042653] iwl4965 0000:10:00.0: On demand firmware reload [ 12.042690] ieee80211 phy0: il4965_irq_tasklet End inta 0x00000000, enabled 0xaa00008b, fh 0x00000000, flags 0x00000282 [ 12.052207] ieee80211 phy0: il4965_mac_start enter [ 12.052212] ieee80211 phy0: il_prep_station Add STA to driver ID 31: ff:ff:ff:ff:ff:ff [ 12.052244] ieee80211 phy0: il4965_set_hw_ready hardware ready [ 12.052324] ieee80211 phy0: il_apm_init Init card's basic functions [ 12.052348] ieee80211 phy0: il_apm_init L1 Enabled; Disabling L0S [ 12.055727] ieee80211 phy0: il4965_load_bsm Begin load bsm [ 12.056140] ieee80211 phy0: il4965_verify_bsm Begin verify bsm [ 12.058642] ieee80211 phy0: il4965_verify_bsm BSM bootstrap uCode image OK [ 12.058721] ieee80211 phy0: il4965_load_bsm BSM write complete, poll 1 iterations [ 12.058734] ieee80211 phy0: __il4965_up iwl4965 is coming up [ 12.058737] ieee80211 phy0: il4965_mac_start Start UP work done. [ 12.058757] ieee80211 phy0: __il4965_down iwl4965 is going down [ 12.058761] ieee80211 phy0: il_scan_cancel_timeout Scan cancel timeout [ 12.058762] ieee80211 phy0: il_do_scan_abort Not performing scan to abort [ 12.058765] ieee80211 phy0: il_clear_ucode_stations Clearing ucode stations in driver [ 12.058767] ieee80211 phy0: il_clear_ucode_stations No active stations found to be cleared [ 12.058819] ieee80211 phy0: _il_apm_stop Stop card, put in low power state [ 12.058827] ieee80211 phy0: _il_apm_stop_master stop master [ 12.058864] ieee80211 phy0: il4965_clear_free_frames 0 frames on pre-allocated heap on clear. [ 12.058869] ieee80211 phy0: Hardware restart was requested [ 16.132299] iwl4965 0000:10:00.0: START_ALIVE timeout after 4000ms. [ 16.132303] ------------[ cut here ]------------ [ 16.132304] Hardware became unavailable upon resume. This could be a software issue prior to suspend or a hardware issue. [ 16.132338] WARNING: CPU: 0 PID: 181 at net/mac80211/util.c:1826 ieee80211_reconfig+0x8f/0x14b0 [mac80211] [ 16.132390] Modules linked in: ctr ccm sch_fq_codel xt_tcpudp xt_multiport xt_state iptable_filter iptable_nat nf_nat nf_conntrack nf_defrag_ipv4 ip_tables x_tables binfmt_misc joydev mousedev btusb btrtl btintel btbcm bluetooth ecdh_generic ecc iTCO_wdt i2c_dev iwl4965 iwlegacy coretemp snd_hda_codec_analog pcspkr psmouse mac80211 snd_hda_codec_generic libarc4 sdhci_pci cqhci sha256_generic sdhci libsha256 firewire_ohci snd_hda_intel snd_intel_dspcfg mmc_core snd_hda_codec snd_hwdep firewire_core led_class iosf_mbi snd_hda_core uhci_hcd lpc_ich crc_itu_t cfg80211 ehci_pci ehci_hcd snd_pcm usbcore mfd_core rfkill snd_timer snd usb_common soundcore video parport_pc parport intel_agp wmi intel_gtt backlight e1000e agpgart evdev [ 16.132456] CPU: 0 UID: 0 PID: 181 Comm: kworker/u8:6 Not tainted 6.11.0-cl+ #143 [ 16.132460] Hardware name: Hewlett-Packard HP Compaq 6910p/30BE, BIOS 68MCU Ver. F.19 07/06/2010 [ 16.132463] Workqueue: async async_run_entry_fn [ 16.132469] RIP: 0010:ieee80211_reconfig+0x8f/0x14b0 [mac80211] [ 16.132501] Code: da 02 00 0 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: avoid hci_dev_test_and_set_flag() in mgmt_init_hdev() syzbot is again reporting attempt to cancel uninitialized work at mgmt_index_removed() [1], for setting of HCI_MGMT flag from mgmt_init_hdev() from hci_mgmt_cmd() from hci_sock_sendmsg() can race with testing of HCI_MGMT flag from mgmt_index_removed() from hci_sock_bind() due to lack of serialization via hci_dev_lock(). Since mgmt_init_hdev() is called with mgmt_chan_list_lock held, we can safely split hci_dev_test_and_set_flag() into hci_dev_test_flag() and hci_dev_set_flag(). Thus, in order to close this race, set HCI_MGMT flag after INIT_DELAYED_WORK() completed. This is a local fix based on mgmt_chan_list_lock. Lack of serialization via hci_dev_lock() might be causing different race conditions somewhere else. But a global fix based on hci_dev_lock() should deserve a future patch.

In the Linux kernel, the following vulnerability has been resolved: mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW Ever since the Dirty COW (CVE-2016-5195) security issue happened, we know that FOLL_FORCE can be possibly dangerous, especially if there are races that can be exploited by user space. Right now, it would be sufficient to have some code that sets a PTE of a R/O-mapped shared page dirty, in order for it to erroneously become writable by FOLL_FORCE. The implications of setting a write-protected PTE dirty might not be immediately obvious to everyone. And in fact ever since commit 9ae0f87d009c ("mm/shmem: unconditionally set pte dirty in mfill_atomic_install_pte"), we can use UFFDIO_CONTINUE to map a shmem page R/O while marking the pte dirty. This can be used by unprivileged user space to modify tmpfs/shmem file content even if the user does not have write permissions to the file, and to bypass memfd write sealing -- Dirty COW restricted to tmpfs/shmem (CVE-2022-2590). To fix such security issues for good, the insight is that we really only need that fancy retry logic (FOLL_COW) for COW mappings that are not writable (!VM_WRITE). And in a COW mapping, we really only broke COW if we have an exclusive anonymous page mapped. If we have something else mapped, or the mapped anonymous page might be shared (!PageAnonExclusive), we have to trigger a write fault to break COW. If we don't find an exclusive anonymous page when we retry, we have to trigger COW breaking once again because something intervened. Let's move away from this mandatory-retry + dirty handling and rely on our PageAnonExclusive() flag for making a similar decision, to use the same COW logic as in other kernel parts here as well. In case we stumble over a PTE in a COW mapping that does not map an exclusive anonymous page, COW was not properly broken and we have to trigger a fake write-fault to break COW. Just like we do in can_change_pte_writable() added via commit 64fe24a3e05e ("mm/mprotect: try avoiding write faults for exclusive anonymous pages when changing protection") and commit 76aefad628aa ("mm/mprotect: fix soft-dirty check in can_change_pte_writable()"), take care of softdirty and uffd-wp manually. For example, a write() via /proc/self/mem to a uffd-wp-protected range has to fail instead of silently granting write access and bypassing the userspace fault handler. Note that FOLL_FORCE is not only used for debug access, but also triggered by applications without debug intentions, for example, when pinning pages via RDMA. This fixes CVE-2022-2590. Note that only x86_64 and aarch64 are affected, because only those support CONFIG_HAVE_ARCH_USERFAULTFD_MINOR. Fortunately, FOLL_COW is no longer required to handle FOLL_FORCE. So let's just get rid of it. Thanks to Nadav Amit for pointing out that the pte_dirty() check in FOLL_FORCE code is problematic and might be exploitable. Note 1: We don't check for the PTE being dirty because it doesn't matter for making a "was COWed" decision anymore, and whoever modifies the page has to set the page dirty either way. Note 2: Kernels before extended uffd-wp support and before PageAnonExclusive (< 5.19) can simply revert the problematic commit instead and be safe regarding UFFDIO_CONTINUE. A backport to v5.19 requires minor adjustments due to lack of vma_soft_dirty_enabled().

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix race setting file private on concurrent lseek using same fd When doing concurrent lseek(2) system calls against the same file descriptor, using multiple threads belonging to the same process, we have a short time window where a race happens and can result in a memory leak. The race happens like this: 1) A program opens a file descriptor for a file and then spawns two threads (with the pthreads library for example), lets call them task A and task B; 2) Task A calls lseek with SEEK_DATA or SEEK_HOLE and ends up at file.c:find_desired_extent() while holding a read lock on the inode; 3) At the start of find_desired_extent(), it extracts the file's private_data pointer into a local variable named 'private', which has a value of NULL; 4) Task B also calls lseek with SEEK_DATA or SEEK_HOLE, locks the inode in shared mode and enters file.c:find_desired_extent(), where it also extracts file->private_data into its local variable 'private', which has a NULL value; 5) Because it saw a NULL file private, task A allocates a private structure and assigns to the file structure; 6) Task B also saw a NULL file private so it also allocates its own file private and then assigns it to the same file structure, since both tasks are using the same file descriptor. At this point we leak the private structure allocated by task A. Besides the memory leak, there's also the detail that both tasks end up using the same cached state record in the private structure (struct btrfs_file_private::llseek_cached_state), which can result in a use-after-free problem since one task can free it while the other is still using it (only one task took a reference count on it). Also, sharing the cached state is not a good idea since it could result in incorrect results in the future - right now it should not be a problem because it end ups being used only in extent-io-tree.c:count_range_bits() where we do range validation before using the cached state. Fix this by protecting the private assignment and check of a file while holding the inode's spinlock and keep track of the task that allocated the private, so that it's used only by that task in order to prevent user-after-free issues with the cached state record as well as potentially using it incorrectly in the future.

In the Linux kernel, the following vulnerability has been resolved: riscv: fix race when vmap stack overflow Currently, when detecting vmap stack overflow, riscv firstly switches to the so called shadow stack, then use this shadow stack to call the get_overflow_stack() to get the overflow stack. However, there's a race here if two or more harts use the same shadow stack at the same time. To solve this race, we introduce spin_shadow_stack atomic var, which will be swap between its own address and 0 in atomic way, when the var is set, it means the shadow_stack is being used; when the var is cleared, it means the shadow_stack isn't being used. [Palmer: Add AQ to the swap, and also some comments.]

In the Linux kernel, the following vulnerability has been resolved: tcp: TX zerocopy should not sense pfmemalloc status We got a recent syzbot report [1] showing a possible misuse of pfmemalloc page status in TCP zerocopy paths. Indeed, for pages coming from user space or other layers, using page_is_pfmemalloc() is moot, and possibly could give false positives. There has been attempts to make page_is_pfmemalloc() more robust, but not using it in the first place in this context is probably better, removing cpu cycles. Note to stable teams : You need to backport 84ce071e38a6 ("net: introduce __skb_fill_page_desc_noacc") as a prereq. Race is more probable after commit c07aea3ef4d4 ("mm: add a signature in struct page") because page_is_pfmemalloc() is now using low order bit from page->lru.next, which can change more often than page->index. Low order bit should never be set for lru.next (when used as an anchor in LRU list), so KCSAN report is mostly a false positive. Backporting to older kernel versions seems not necessary. [1] BUG: KCSAN: data-race in lru_add_fn / tcp_build_frag write to 0xffffea0004a1d2c8 of 8 bytes by task 18600 on cpu 0: __list_add include/linux/list.h:73 [inline] list_add include/linux/list.h:88 [inline] lruvec_add_folio include/linux/mm_inline.h:105 [inline] lru_add_fn+0x440/0x520 mm/swap.c:228 folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246 folio_batch_add_and_move mm/swap.c:263 [inline] folio_add_lru+0xf1/0x140 mm/swap.c:490 filemap_add_folio+0xf8/0x150 mm/filemap.c:948 __filemap_get_folio+0x510/0x6d0 mm/filemap.c:1981 pagecache_get_page+0x26/0x190 mm/folio-compat.c:104 grab_cache_page_write_begin+0x2a/0x30 mm/folio-compat.c:116 ext4_da_write_begin+0x2dd/0x5f0 fs/ext4/inode.c:2988 generic_perform_write+0x1d4/0x3f0 mm/filemap.c:3738 ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:270 ext4_file_write_iter+0x2e3/0x1210 call_write_iter include/linux/fs.h:2187 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x468/0x760 fs/read_write.c:578 ksys_write+0xe8/0x1a0 fs/read_write.c:631 __do_sys_write fs/read_write.c:643 [inline] __se_sys_write fs/read_write.c:640 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:640 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffffea0004a1d2c8 of 8 bytes by task 18611 on cpu 1: page_is_pfmemalloc include/linux/mm.h:1740 [inline] __skb_fill_page_desc include/linux/skbuff.h:2422 [inline] skb_fill_page_desc include/linux/skbuff.h:2443 [inline] tcp_build_frag+0x613/0xb20 net/ipv4/tcp.c:1018 do_tcp_sendpages+0x3e8/0xaf0 net/ipv4/tcp.c:1075 tcp_sendpage_locked net/ipv4/tcp.c:1140 [inline] tcp_sendpage+0x89/0xb0 net/ipv4/tcp.c:1150 inet_sendpage+0x7f/0xc0 net/ipv4/af_inet.c:833 kernel_sendpage+0x184/0x300 net/socket.c:3561 sock_sendpage+0x5a/0x70 net/socket.c:1054 pipe_to_sendpage+0x128/0x160 fs/splice.c:361 splice_from_pipe_feed fs/splice.c:415 [inline] __splice_from_pipe+0x222/0x4d0 fs/splice.c:559 splice_from_pipe fs/splice.c:594 [inline] generic_splice_sendpage+0x89/0xc0 fs/splice.c:743 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:931 splice_direct_to_actor+0x305/0x620 fs/splice.c:886 do_splice_direct+0xfb/0x180 fs/splice.c:974 do_sendfile+0x3bf/0x910 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64 fs/read_write.c:1303 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1303 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000000000 -> 0xffffea0004a1d288 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 18611 Comm: syz-executor.4 Not tainted 6.0.0-rc2-syzkaller-00248-ge022620b5d05-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022

In the Linux kernel, the following vulnerability has been resolved: exec: Fix ToCToU between perm check and set-uid/gid usage When opening a file for exec via do_filp_open(), permission checking is done against the file's metadata at that moment, and on success, a file pointer is passed back. Much later in the execve() code path, the file metadata (specifically mode, uid, and gid) is used to determine if/how to set the uid and gid. However, those values may have changed since the permissions check, meaning the execution may gain unintended privileges. For example, if a file could change permissions from executable and not set-id: ---------x 1 root root 16048 Aug 7 13:16 target to set-id and non-executable: ---S------ 1 root root 16048 Aug 7 13:16 target it is possible to gain root privileges when execution should have been disallowed. While this race condition is rare in real-world scenarios, it has been observed (and proven exploitable) when package managers are updating the setuid bits of installed programs. Such files start with being world-executable but then are adjusted to be group-exec with a set-uid bit. For example, "chmod o-x,u+s target" makes "target" executable only by uid "root" and gid "cdrom", while also becoming setuid-root: -rwxr-xr-x 1 root cdrom 16048 Aug 7 13:16 target becomes: -rwsr-xr-- 1 root cdrom 16048 Aug 7 13:16 target But racing the chmod means users without group "cdrom" membership can get the permission to execute "target" just before the chmod, and when the chmod finishes, the exec reaches brpm_fill_uid(), and performs the setuid to root, violating the expressed authorization of "only cdrom group members can setuid to root". Re-check that we still have execute permissions in case the metadata has changed. It would be better to keep a copy from the perm-check time, but until we can do that refactoring, the least-bad option is to do a full inode_permission() call (under inode lock). It is understood that this is safe against dead-locks, but hardly optimal.

In the Linux kernel, the following vulnerability has been resolved: gve: Account for stopped queues when reading NIC stats We now account for the fact that the NIC might send us stats for a subset of queues. Without this change, gve_get_ethtool_stats might make an invalid access on the priv->stats_report->stats array.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Using uninitialized value *size when calling amdgpu_vce_cs_reloc Initialize the size before calling amdgpu_vce_cs_reloc, such as case 0x03000001. V2: To really improve the handling we would actually need to have a separate value of 0xffffffff.(Christian)