Race condition in ip_vs_conn_flush in Linux 2.6 before 2.6.13 and 2.4 before 2.4.32-pre2, when running on SMP systems, allows local users to cause a denial of service (null dereference) by causing a connection timer to expire while the connection table is being flushed before the appropriate lock is acquired.

Race condition in Linux 2.6, when threads are sharing memory mapping via CLONE_VM (such as linuxthreads and vfork), might allow local users to cause a denial of service (deadlock) by triggering a core dump while waiting for a thread that has just performed an exec.

In the Linux kernel, the following vulnerability has been resolved: drm/bridge: sii902x: Fix probing race issue A null pointer dereference crash has been observed rarely on TI platforms using sii9022 bridge: [ 53.271356] sii902x_get_edid+0x34/0x70 [sii902x] [ 53.276066] sii902x_bridge_get_edid+0x14/0x20 [sii902x] [ 53.281381] drm_bridge_get_edid+0x20/0x34 [drm] [ 53.286305] drm_bridge_connector_get_modes+0x8c/0xcc [drm_kms_helper] [ 53.292955] drm_helper_probe_single_connector_modes+0x190/0x538 [drm_kms_helper] [ 53.300510] drm_client_modeset_probe+0x1f0/0xbd4 [drm] [ 53.305958] __drm_fb_helper_initial_config_and_unlock+0x50/0x510 [drm_kms_helper] [ 53.313611] drm_fb_helper_initial_config+0x48/0x58 [drm_kms_helper] [ 53.320039] drm_fbdev_dma_client_hotplug+0x84/0xd4 [drm_dma_helper] [ 53.326401] drm_client_register+0x5c/0xa0 [drm] [ 53.331216] drm_fbdev_dma_setup+0xc8/0x13c [drm_dma_helper] [ 53.336881] tidss_probe+0x128/0x264 [tidss] [ 53.341174] platform_probe+0x68/0xc4 [ 53.344841] really_probe+0x188/0x3c4 [ 53.348501] __driver_probe_device+0x7c/0x16c [ 53.352854] driver_probe_device+0x3c/0x10c [ 53.357033] __device_attach_driver+0xbc/0x158 [ 53.361472] bus_for_each_drv+0x88/0xe8 [ 53.365303] __device_attach+0xa0/0x1b4 [ 53.369135] device_initial_probe+0x14/0x20 [ 53.373314] bus_probe_device+0xb0/0xb4 [ 53.377145] deferred_probe_work_func+0xcc/0x124 [ 53.381757] process_one_work+0x1f0/0x518 [ 53.385770] worker_thread+0x1e8/0x3dc [ 53.389519] kthread+0x11c/0x120 [ 53.392750] ret_from_fork+0x10/0x20 The issue here is as follows: - tidss probes, but is deferred as sii902x is still missing. - sii902x starts probing and enters sii902x_init(). - sii902x calls drm_bridge_add(). Now the sii902x bridge is ready from DRM's perspective. - sii902x calls sii902x_audio_codec_init() and platform_device_register_data() - The registration of the audio platform device causes probing of the deferred devices. - tidss probes, which eventually causes sii902x_bridge_get_edid() to be called. - sii902x_bridge_get_edid() tries to use the i2c to read the edid. However, the sii902x driver has not set up the i2c part yet, leading to the crash. Fix this by moving the drm_bridge_add() to the end of the sii902x_init(), which is also at the very end of sii902x_probe().

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: 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: 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: tls: fix race between async notify and socket close The submitting thread (one which called recvmsg/sendmsg) may exit as soon as the async crypto handler calls complete() so any code past that point risks touching already freed data. Try to avoid the locking and extra flags altogether. Have the main thread hold an extra reference, this way we can depend solely on the atomic ref counter for synchronization. Don't futz with reiniting the completion, either, we are now tightly controlling when completion fires.

In the Linux kernel, the following vulnerability has been resolved: blk-mq: fix IO hang from sbitmap wakeup race In blk_mq_mark_tag_wait(), __add_wait_queue() may be re-ordered with the following blk_mq_get_driver_tag() in case of getting driver tag failure. Then in __sbitmap_queue_wake_up(), waitqueue_active() may not observe the added waiter in blk_mq_mark_tag_wait() and wake up nothing, meantime blk_mq_mark_tag_wait() can't get driver tag successfully. This issue can be reproduced by running the following test in loop, and fio hang can be observed in < 30min when running it on my test VM in laptop. modprobe -r scsi_debug modprobe scsi_debug delay=0 dev_size_mb=4096 max_queue=1 host_max_queue=1 submit_queues=4 dev=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/* | head -1 | xargs basename` fio --filename=/dev/"$dev" --direct=1 --rw=randrw --bs=4k --iodepth=1 \ --runtime=100 --numjobs=40 --time_based --name=test \ --ioengine=libaio Fix the issue by adding one explicit barrier in blk_mq_mark_tag_wait(), which is just fine in case of running out of tag.

In the Linux kernel, the following vulnerability has been resolved: pds_core: Prevent race issues involving the adminq There are multiple paths that can result in using the pdsc's adminq. [1] pdsc_adminq_isr and the resulting work from queue_work(), i.e. pdsc_work_thread()->pdsc_process_adminq() [2] pdsc_adminq_post() When the device goes through reset via PCIe reset and/or a fw_down/fw_up cycle due to bad PCIe state or bad device state the adminq is destroyed and recreated. A NULL pointer dereference can happen if [1] or [2] happens after the adminq is already destroyed. In order to fix this, add some further state checks and implement reference counting for adminq uses. Reference counting was used because multiple threads can attempt to access the adminq at the same time via [1] or [2]. Additionally, multiple clients (i.e. pds-vfio-pci) can be using [2] at the same time. The adminq_refcnt is initialized to 1 when the adminq has been allocated and is ready to use. Users/clients of the adminq (i.e. [1] and [2]) will increment the refcnt when they are using the adminq. When the driver goes into a fw_down cycle it will set the PDSC_S_FW_DEAD bit and then wait for the adminq_refcnt to hit 1. Setting the PDSC_S_FW_DEAD before waiting will prevent any further adminq_refcnt increments. Waiting for the adminq_refcnt to hit 1 allows for any current users of the adminq to finish before the driver frees the adminq. Once the adminq_refcnt hits 1 the driver clears the refcnt to signify that the adminq is deleted and cannot be used. On the fw_up cycle the driver will once again initialize the adminq_refcnt to 1 allowing the adminq to be used again.

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: 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.

A race condition was discovered in get_old_root in fs/btrfs/ctree.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (BUG) because of a lack of locking on an extent buffer before a cloning operation, aka CID-dbcc7d57bffc.

A race condition was found in the Linux kernel's media/dvb-core in dvbdmx_write() function. This can result in a null pointer dereference issue, possibly leading to a kernel panic or denial of service issue.

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix race between searching chunks and release journal_head from buffer_head Encountered a race between ocfs2_test_bg_bit_allocatable() and jbd2_journal_put_journal_head() resulting in the below vmcore. PID: 106879 TASK: ffff880244ba9c00 CPU: 2 COMMAND: "loop3" Call trace: panic oops_end no_context __bad_area_nosemaphore bad_area_nosemaphore __do_page_fault do_page_fault page_fault [exception RIP: ocfs2_block_group_find_clear_bits+316] ocfs2_block_group_find_clear_bits [ocfs2] ocfs2_cluster_group_search [ocfs2] ocfs2_search_chain [ocfs2] ocfs2_claim_suballoc_bits [ocfs2] __ocfs2_claim_clusters [ocfs2] ocfs2_claim_clusters [ocfs2] ocfs2_local_alloc_slide_window [ocfs2] ocfs2_reserve_local_alloc_bits [ocfs2] ocfs2_reserve_clusters_with_limit [ocfs2] ocfs2_reserve_clusters [ocfs2] ocfs2_lock_refcount_allocators [ocfs2] ocfs2_make_clusters_writable [ocfs2] ocfs2_replace_cow [ocfs2] ocfs2_refcount_cow [ocfs2] ocfs2_file_write_iter [ocfs2] lo_rw_aio loop_queue_work kthread_worker_fn kthread ret_from_fork When ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the bg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and released the jounal head from the buffer head. Needed to take bit lock for the bit 'BH_JournalHead' to fix this race.

In the Linux kernel, the following vulnerability has been resolved: f2fs: compress: fix race condition of overwrite vs truncate pos_fsstress testcase complains a panic as belew: ------------[ cut here ]------------ kernel BUG at fs/f2fs/compress.c:1082! invalid opcode: 0000 [#1] SMP PTI CPU: 4 PID: 2753477 Comm: kworker/u16:2 Tainted: G OE 5.12.0-rc1-custom #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: writeback wb_workfn (flush-252:16) RIP: 0010:prepare_compress_overwrite+0x4c0/0x760 [f2fs] Call Trace: f2fs_prepare_compress_overwrite+0x5f/0x80 [f2fs] f2fs_write_cache_pages+0x468/0x8a0 [f2fs] f2fs_write_data_pages+0x2a4/0x2f0 [f2fs] do_writepages+0x38/0xc0 __writeback_single_inode+0x44/0x2a0 writeback_sb_inodes+0x223/0x4d0 __writeback_inodes_wb+0x56/0xf0 wb_writeback+0x1dd/0x290 wb_workfn+0x309/0x500 process_one_work+0x220/0x3c0 worker_thread+0x53/0x420 kthread+0x12f/0x150 ret_from_fork+0x22/0x30 The root cause is truncate() may race with overwrite as below, so that one reference count left in page can not guarantee the page attaching in mapping tree all the time, after truncation, later find_lock_page() may return NULL pointer. - prepare_compress_overwrite - f2fs_pagecache_get_page - unlock_page - f2fs_setattr - truncate_setsize - truncate_inode_page - delete_from_page_cache - find_lock_page Fix this by avoiding referencing updated page.

In the Linux kernel, the following vulnerability has been resolved: udp: fix race between close() and udp_abort() Kaustubh reported and diagnosed a panic in udp_lib_lookup(). The root cause is udp_abort() racing with close(). Both racing functions acquire the socket lock, but udp{v6}_destroy_sock() release it before performing destructive actions. We can't easily extend the socket lock scope to avoid the race, instead use the SOCK_DEAD flag to prevent udp_abort from doing any action when the critical race happens. Diagnosed-and-tested-by: Kaustubh Pandey <kapandey@codeaurora.org>

A null pointer dereference flaw was found in the Linux kernel API for the cryptographic algorithm scatterwalk functionality. This issue occurs when a user constructs a malicious packet with specific socket configuration, which could allow a local user to crash the system or escalate their privileges on the system.

Memory leaks in *create_resource_pool() functions under drivers/gpu/drm/amd/display/dc in the Linux kernel through 5.3.11 allow attackers to cause a denial of service (memory consumption). This affects the dce120_create_resource_pool() function in drivers/gpu/drm/amd/display/dc/dce120/dce120_resource.c, the dce110_create_resource_pool() function in drivers/gpu/drm/amd/display/dc/dce110/dce110_resource.c, the dce100_create_resource_pool() function in drivers/gpu/drm/amd/display/dc/dce100/dce100_resource.c, the dcn10_create_resource_pool() function in drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c, and the dce112_create_resource_pool() function in drivers/gpu/drm/amd/display/dc/dce112/dce112_resource.c, aka CID-104c307147ad.

A memory leak in the cx23888_ir_probe() function in drivers/media/pci/cx23885/cx23888-ir.c in the Linux kernel through 5.3.11 allows attackers to cause a denial of service (memory consumption) by triggering kfifo_alloc() failures, aka CID-a7b2df76b42b.

A use-after-free vulnerability was found in network namespaces code affecting the Linux kernel before 4.14.11. The function get_net_ns_by_id() in net/core/net_namespace.c does not check for the net::count value after it has found a peer network in netns_ids idr, which could lead to double free and memory corruption. This vulnerability could allow an unprivileged local user to induce kernel memory corruption on the system, leading to a crash. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although it is thought to be unlikely.

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: 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: net/mlx5e: Check for NOT_READY flag state after locking Currently the check for NOT_READY flag is performed before obtaining the necessary lock. This opens a possibility for race condition when the flow is concurrently removed from unready_flows list by the workqueue task, which causes a double-removal from the list and a crash[0]. Fix the issue by moving the flag check inside the section protected by uplink_priv->unready_flows_lock mutex. [0]: [44376.389654] general protection fault, probably for non-canonical address 0xdead000000000108: 0000 [#1] SMP [44376.391665] CPU: 7 PID: 59123 Comm: tc Not tainted 6.4.0-rc4+ #1 [44376.392984] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [44376.395342] RIP: 0010:mlx5e_tc_del_fdb_flow+0xb3/0x340 [mlx5_core] [44376.396857] Code: 00 48 8b b8 68 ce 02 00 e8 8a 4d 02 00 4c 8d a8 a8 01 00 00 4c 89 ef e8 8b 79 88 e1 48 8b 83 98 06 00 00 48 8b 93 90 06 00 00 <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 83 90 06 [44376.399167] RSP: 0018:ffff88812cc97570 EFLAGS: 00010246 [44376.399680] RAX: dead000000000122 RBX: ffff8881088e3800 RCX: ffff8881881bac00 [44376.400337] RDX: dead000000000100 RSI: ffff88812cc97500 RDI: ffff8881242f71b0 [44376.401001] RBP: ffff88811cbb0940 R08: 0000000000000400 R09: 0000000000000001 [44376.401663] R10: 0000000000000001 R11: 0000000000000000 R12: ffff88812c944000 [44376.402342] R13: ffff8881242f71a8 R14: ffff8881222b4000 R15: 0000000000000000 [44376.402999] FS: 00007f0451104800(0000) GS:ffff88852cb80000(0000) knlGS:0000000000000000 [44376.403787] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [44376.404343] CR2: 0000000000489108 CR3: 0000000123a79003 CR4: 0000000000370ea0 [44376.405004] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [44376.405665] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [44376.406339] Call Trace: [44376.406651] <TASK> [44376.406939] ? die_addr+0x33/0x90 [44376.407311] ? exc_general_protection+0x192/0x390 [44376.407795] ? asm_exc_general_protection+0x22/0x30 [44376.408292] ? mlx5e_tc_del_fdb_flow+0xb3/0x340 [mlx5_core] [44376.408876] __mlx5e_tc_del_fdb_peer_flow+0xbc/0xe0 [mlx5_core] [44376.409482] mlx5e_tc_del_flow+0x42/0x210 [mlx5_core] [44376.410055] mlx5e_flow_put+0x25/0x50 [mlx5_core] [44376.410529] mlx5e_delete_flower+0x24b/0x350 [mlx5_core] [44376.411043] tc_setup_cb_reoffload+0x22/0x80 [44376.411462] fl_reoffload+0x261/0x2f0 [cls_flower] [44376.411907] ? mlx5e_rep_indr_setup_ft_cb+0x160/0x160 [mlx5_core] [44376.412481] ? mlx5e_rep_indr_setup_ft_cb+0x160/0x160 [mlx5_core] [44376.413044] tcf_block_playback_offloads+0x76/0x170 [44376.413497] tcf_block_unbind+0x7b/0xd0 [44376.413881] tcf_block_setup+0x17d/0x1c0 [44376.414269] tcf_block_offload_cmd.isra.0+0xf1/0x130 [44376.414725] tcf_block_offload_unbind+0x43/0x70 [44376.415153] __tcf_block_put+0x82/0x150 [44376.415532] ingress_destroy+0x22/0x30 [sch_ingress] [44376.415986] qdisc_destroy+0x3b/0xd0 [44376.416343] qdisc_graft+0x4d0/0x620 [44376.416706] tc_get_qdisc+0x1c9/0x3b0 [44376.417074] rtnetlink_rcv_msg+0x29c/0x390 [44376.419978] ? rep_movs_alternative+0x3a/0xa0 [44376.420399] ? rtnl_calcit.isra.0+0x120/0x120 [44376.420813] netlink_rcv_skb+0x54/0x100 [44376.421192] netlink_unicast+0x1f6/0x2c0 [44376.421573] netlink_sendmsg+0x232/0x4a0 [44376.421980] sock_sendmsg+0x38/0x60 [44376.422328] ____sys_sendmsg+0x1d0/0x1e0 [44376.422709] ? copy_msghdr_from_user+0x6d/0xa0 [44376.423127] ___sys_sendmsg+0x80/0xc0 [44376.423495] ? ___sys_recvmsg+0x8b/0xc0 [44376.423869] __sys_sendmsg+0x51/0x90 [44376.424226] do_syscall_64+0x3d/0x90 [44376.424587] entry_SYSCALL_64_after_hwframe+0x46/0xb0 [44376.425046] RIP: 0033:0x7f045134f887 [44376.425403] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 ---truncated---

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: nfsd: fix handling of cached open files in nfsd4_open codepath Commit fb70bf124b05 ("NFSD: Instantiate a struct file when creating a regular NFSv4 file") added the ability to cache an open fd over a compound. There are a couple of problems with the way this currently works: It's racy, as a newly-created nfsd_file can end up with its PENDING bit cleared while the nf is hashed, and the nf_file pointer is still zeroed out. Other tasks can find it in this state and they expect to see a valid nf_file, and can oops if nf_file is NULL. Also, there is no guarantee that we'll end up creating a new nfsd_file if one is already in the hash. If an extant entry is in the hash with a valid nf_file, nfs4_get_vfs_file will clobber its nf_file pointer with the value of op_file and the old nf_file will leak. Fix both issues by making a new nfsd_file_acquirei_opened variant that takes an optional file pointer. If one is present when this is called, we'll take a new reference to it instead of trying to open the file. If the nfsd_file already has a valid nf_file, we'll just ignore the optional file and pass the nfsd_file back as-is. Also rework the tracepoints a bit to allow for an "opened" variant and don't try to avoid counting acquisitions in the case where we already have a cached open file.

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: af_unix: Fix data-races around user->unix_inflight. user->unix_inflight is changed under spin_lock(unix_gc_lock), but too_many_unix_fds() reads it locklessly. Let's annotate the write/read accesses to user->unix_inflight. BUG: KCSAN: data-race in unix_attach_fds / unix_inflight write to 0xffffffff8546f2d0 of 8 bytes by task 44798 on cpu 1: unix_inflight+0x157/0x180 net/unix/scm.c:66 unix_attach_fds+0x147/0x1e0 net/unix/scm.c:123 unix_scm_to_skb net/unix/af_unix.c:1827 [inline] unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1950 unix_seqpacket_sendmsg net/unix/af_unix.c:2308 [inline] unix_seqpacket_sendmsg+0xba/0x130 net/unix/af_unix.c:2292 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0x148/0x160 net/socket.c:748 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2494 ___sys_sendmsg+0xc6/0x140 net/socket.c:2548 __sys_sendmsg+0x94/0x140 net/socket.c:2577 __do_sys_sendmsg net/socket.c:2586 [inline] __se_sys_sendmsg net/socket.c:2584 [inline] __x64_sys_sendmsg+0x45/0x50 net/socket.c:2584 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 read to 0xffffffff8546f2d0 of 8 bytes by task 44814 on cpu 0: too_many_unix_fds net/unix/scm.c:101 [inline] unix_attach_fds+0x54/0x1e0 net/unix/scm.c:110 unix_scm_to_skb net/unix/af_unix.c:1827 [inline] unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1950 unix_seqpacket_sendmsg net/unix/af_unix.c:2308 [inline] unix_seqpacket_sendmsg+0xba/0x130 net/unix/af_unix.c:2292 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0x148/0x160 net/socket.c:748 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2494 ___sys_sendmsg+0xc6/0x140 net/socket.c:2548 __sys_sendmsg+0x94/0x140 net/socket.c:2577 __do_sys_sendmsg net/socket.c:2586 [inline] __se_sys_sendmsg net/socket.c:2584 [inline] __x64_sys_sendmsg+0x45/0x50 net/socket.c:2584 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 value changed: 0x000000000000000c -> 0x000000000000000d Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 44814 Comm: systemd-coredum Not tainted 6.4.0-11989-g6843306689af #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

In the Linux kernel, the following vulnerability has been resolved: mm: kmem: fix a NULL pointer dereference in obj_stock_flush_required() KCSAN found an issue in obj_stock_flush_required(): stock->cached_objcg can be reset between the check and dereference: ================================================================== BUG: KCSAN: data-race in drain_all_stock / drain_obj_stock write to 0xffff888237c2a2f8 of 8 bytes by task 19625 on cpu 0: drain_obj_stock+0x408/0x4e0 mm/memcontrol.c:3306 refill_obj_stock+0x9c/0x1e0 mm/memcontrol.c:3340 obj_cgroup_uncharge+0xe/0x10 mm/memcontrol.c:3408 memcg_slab_free_hook mm/slab.h:587 [inline] __cache_free mm/slab.c:3373 [inline] __do_kmem_cache_free mm/slab.c:3577 [inline] kmem_cache_free+0x105/0x280 mm/slab.c:3602 __d_free fs/dcache.c:298 [inline] dentry_free fs/dcache.c:375 [inline] __dentry_kill+0x422/0x4a0 fs/dcache.c:621 dentry_kill+0x8d/0x1e0 dput+0x118/0x1f0 fs/dcache.c:913 __fput+0x3bf/0x570 fs/file_table.c:329 ____fput+0x15/0x20 fs/file_table.c:349 task_work_run+0x123/0x160 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xcf/0xe0 kernel/entry/common.c:171 exit_to_user_mode_prepare+0x6a/0xa0 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff888237c2a2f8 of 8 bytes by task 19632 on cpu 1: obj_stock_flush_required mm/memcontrol.c:3319 [inline] drain_all_stock+0x174/0x2a0 mm/memcontrol.c:2361 try_charge_memcg+0x6d0/0xd10 mm/memcontrol.c:2703 try_charge mm/memcontrol.c:2837 [inline] mem_cgroup_charge_skmem+0x51/0x140 mm/memcontrol.c:7290 sock_reserve_memory+0xb1/0x390 net/core/sock.c:1025 sk_setsockopt+0x800/0x1e70 net/core/sock.c:1525 udp_lib_setsockopt+0x99/0x6c0 net/ipv4/udp.c:2692 udp_setsockopt+0x73/0xa0 net/ipv4/udp.c:2817 sock_common_setsockopt+0x61/0x70 net/core/sock.c:3668 __sys_setsockopt+0x1c3/0x230 net/socket.c:2271 __do_sys_setsockopt net/socket.c:2282 [inline] __se_sys_setsockopt net/socket.c:2279 [inline] __x64_sys_setsockopt+0x66/0x80 net/socket.c:2279 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: 0xffff8881382d52c0 -> 0xffff888138893740 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 19632 Comm: syz-executor.0 Not tainted 6.3.0-rc2-syzkaller-00387-g534293368afa #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Fix it by using READ_ONCE()/WRITE_ONCE() for all accesses to stock->cached_objcg.

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: 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: 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: 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: 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: iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind When unbinding pasid - a race condition exists vs outstanding page faults. To prevent this, the pasid_state object contains a refcount. * set to 1 on pasid bind * incremented on each ppr notification start * decremented on each ppr notification done * decremented on pasid unbind Since refcount_dec assumes that refcount will never reach 0: the current implementation causes the following to be invoked on pasid unbind: REFCOUNT_WARN("decrement hit 0; leaking memory") Fix this issue by changing refcount_dec to refcount_dec_and_test to explicitly handle refcount=1.

In the Linux kernel, the following vulnerability has been resolved: udp: Deal with race between UDP socket address change and rehash If a UDP socket changes its local address while it's receiving datagrams, as a result of connect(), there is a period during which a lookup operation might fail to find it, after the address is changed but before the secondary hash (port and address) and the four-tuple hash (local and remote ports and addresses) are updated. Secondary hash chains were introduced by commit 30fff9231fad ("udp: bind() optimisation") and, as a result, a rehash operation became needed to make a bound socket reachable again after a connect(). This operation was introduced by commit 719f835853a9 ("udp: add rehash on connect()") which isn't however a complete fix: the socket will be found once the rehashing completes, but not while it's pending. This is noticeable with a socat(1) server in UDP4-LISTEN mode, and a client sending datagrams to it. After the server receives the first datagram (cf. _xioopen_ipdgram_listen()), it issues a connect() to the address of the sender, in order to set up a directed flow. Now, if the client, running on a different CPU thread, happens to send a (subsequent) datagram while the server's socket changes its address, but is not rehashed yet, this will result in a failed lookup and a port unreachable error delivered to the client, as apparent from the following reproducer: LEN=$(($(cat /proc/sys/net/core/wmem_default) / 4)) dd if=/dev/urandom bs=1 count=${LEN} of=tmp.in while :; do taskset -c 1 socat UDP4-LISTEN:1337,null-eof OPEN:tmp.out,create,trunc & sleep 0.1 || sleep 1 taskset -c 2 socat OPEN:tmp.in UDP4:localhost:1337,shut-null wait done where the client will eventually get ECONNREFUSED on a write() (typically the second or third one of a given iteration): 2024/11/13 21:28:23 socat[46901] E write(6, 0x556db2e3c000, 8192): Connection refused This issue was first observed as a seldom failure in Podman's tests checking UDP functionality while using pasta(1) to connect the container's network namespace, which leads us to a reproducer with the lookup error resulting in an ICMP packet on a tap device: LOCAL_ADDR="$(ip -j -4 addr show|jq -rM '.[] | .addr_info[0] | select(.scope == "global").local')" while :; do ./pasta --config-net -p pasta.pcap -u 1337 socat UDP4-LISTEN:1337,null-eof OPEN:tmp.out,create,trunc & sleep 0.2 || sleep 1 socat OPEN:tmp.in UDP4:${LOCAL_ADDR}:1337,shut-null wait cmp tmp.in tmp.out done Once this fails: tmp.in tmp.out differ: char 8193, line 29 we can finally have a look at what's going on: $ tshark -r pasta.pcap 1 0.000000 :: ? ff02::16 ICMPv6 110 Multicast Listener Report Message v2 2 0.168690 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 3 0.168767 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 4 0.168806 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 5 0.168827 c6:47:05:8d:dc:04 ? Broadcast ARP 42 Who has 88.198.0.161? Tell 88.198.0.164 6 0.168851 9a:55:9a:55:9a:55 ? c6:47:05:8d:dc:04 ARP 42 88.198.0.161 is at 9a:55:9a:55:9a:55 7 0.168875 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 8 0.168896 88.198.0.164 ? 88.198.0.161 ICMP 590 Destination unreachable (Port unreachable) 9 0.168926 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 10 0.168959 88.198.0.161 ? 88.198.0.164 UDP 8234 60260 ? 1337 Len=8192 11 0.168989 88.198.0.161 ? 88.198.0.164 UDP 4138 60260 ? 1337 Len=4096 12 0.169010 88.198.0.161 ? 88.198.0.164 UDP 42 60260 ? 1337 Len=0 On the third datagram received, the network namespace of the container initiates an ARP lookup to deliver the ICMP message. In another variant of this reproducer, starting the client with: strace -f pasta --config-net -u 1337 socat UDP4-LISTEN:1337,null-eof OPEN:tmp.out,create,tru ---truncated---

In the Linux kernel, the following vulnerability has been resolved: power: supply: axp288_fuel_gauge: Fix external_power_changed race fuel_gauge_external_power_changed() dereferences info->bat, which gets sets in axp288_fuel_gauge_probe() like this: info->bat = devm_power_supply_register(dev, &fuel_gauge_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 fuel_gauge_external_power_changed() may get called while info->bat has not been set yet leading to a NULL pointer dereference. Fixing this is easy. The external_power_changed callback gets passed the power_supply which will eventually get stored in info->bat, so fuel_gauge_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: ext4: fix racy may inline data check in dio write syzbot reports that the following warning from ext4_iomap_begin() triggers as of the commit referenced below: if (WARN_ON_ONCE(ext4_has_inline_data(inode))) return -ERANGE; This occurs during a dio write, which is never expected to encounter an inode with inline data. To enforce this behavior, ext4_dio_write_iter() checks the current inline state of the inode and clears the MAY_INLINE_DATA state flag to either fall back to buffered writes, or enforce that any other writers in progress on the inode are not allowed to create inline data. The problem is that the check for existing inline data and the state flag can span a lock cycle. For example, if the ilock is originally locked shared and subsequently upgraded to exclusive, another writer may have reacquired the lock and created inline data before the dio write task acquires the lock and proceeds. The commit referenced below loosens the lock requirements to allow some forms of unaligned dio writes to occur under shared lock, but AFAICT the inline data check was technically already racy for any dio write that would have involved a lock cycle. Regardless, lift clearing of the state bit to the same lock critical section that checks for preexisting inline data on the inode to close the race.

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: 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: 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: 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.

drivers/net/wireless/intel/iwlwifi/pcie/trans.c in the Linux kernel 5.2.14 does not check the alloc_workqueue return value, leading to a NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: phy: lynx-28g: serialize concurrent phy_set_mode_ext() calls to shared registers The protocol converter configuration registers PCC8, PCCC, PCCD (implemented by the driver), as well as others, control protocol converters from multiple lanes (each represented as a different struct phy). So, if there are simultaneous calls to phy_set_mode_ext() to lanes sharing the same PCC register (either for the "old" or for the "new" protocol), corruption of the values programmed to hardware is possible, because lynx_28g_rmw() has no locking. Add a spinlock in the struct lynx_28g_priv shared by all lanes, and take the global spinlock from the phy_ops :: set_mode() implementation. There are no other callers which modify PCC registers.

In the Linux kernel, the following vulnerability has been resolved: x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race The SGX EPC reclaimer (ksgxd) may reclaim the SECS EPC page for an enclave and set secs.epc_page to NULL. The SECS page is used for EAUG and ELDU in the SGX page fault handler. However, the NULL check for secs.epc_page is only done for ELDU, not EAUG before being used. Fix this by doing the same NULL check and reloading of the SECS page as needed for both EAUG and ELDU. The SECS page holds global enclave metadata. It can only be reclaimed when there are no other enclave pages remaining. At that point, virtually nothing can be done with the enclave until the SECS page is paged back in. An enclave can not run nor generate page faults without a resident SECS page. But it is still possible for a #PF for a non-SECS page to race with paging out the SECS page: when the last resident non-SECS page A triggers a #PF in a non-resident page B, and then page A and the SECS both are paged out before the #PF on B is handled. Hitting this bug requires that race triggered with a #PF for EAUG. Following is a trace when it happens. BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:sgx_encl_eaug_page+0xc7/0x210 Call Trace: ? __kmem_cache_alloc_node+0x16a/0x440 ? xa_load+0x6e/0xa0 sgx_vma_fault+0x119/0x230 __do_fault+0x36/0x140 do_fault+0x12f/0x400 __handle_mm_fault+0x728/0x1110 handle_mm_fault+0x105/0x310 do_user_addr_fault+0x1ee/0x750 ? __this_cpu_preempt_check+0x13/0x20 exc_page_fault+0x76/0x180 asm_exc_page_fault+0x27/0x30

In the Linux kernel, the following vulnerability has been resolved: smb: During unmount, ensure all cached dir instances drop their dentry The unmount process (cifs_kill_sb() calling close_all_cached_dirs()) can race with various cached directory operations, which ultimately results in dentries not being dropped and these kernel BUGs: BUG: Dentry ffff88814f37e358{i=1000000000080,n=/} still in use (2) [unmount of cifs cifs] VFS: Busy inodes after unmount of cifs (cifs) ------------[ cut here ]------------ kernel BUG at fs/super.c:661! This happens when a cfid is in the process of being cleaned up when, and has been removed from the cfids->entries list, including: - Receiving a lease break from the server - Server reconnection triggers invalidate_all_cached_dirs(), which removes all the cfids from the list - The laundromat thread decides to expire an old cfid. To solve these problems, dropping the dentry is done in queued work done in a newly-added cfid_put_wq workqueue, and close_all_cached_dirs() flushes that workqueue after it drops all the dentries of which it's aware. This is a global workqueue (rather than scoped to a mount), but the queued work is minimal. The final cleanup work for cleaning up a cfid is performed via work queued in the serverclose_wq workqueue; this is done separate from dropping the dentries so that close_all_cached_dirs() doesn't block on any server operations. Both of these queued works expect to invoked with a cfid reference and a tcon reference to avoid those objects from being freed while the work is ongoing. While we're here, add proper locking to close_all_cached_dirs(), and locking around the freeing of cfid->dentry.

In the Linux kernel, the following vulnerability has been resolved: rcu/nocb: Fix missed RCU barrier on deoffloading Currently, running rcutorture test with torture_type=rcu fwd_progress=8 n_barrier_cbs=8 nocbs_nthreads=8 nocbs_toggle=100 onoff_interval=60 test_boost=2, will trigger the following warning: WARNING: CPU: 19 PID: 100 at kernel/rcu/tree_nocb.h:1061 rcu_nocb_rdp_deoffload+0x292/0x2a0 RIP: 0010:rcu_nocb_rdp_deoffload+0x292/0x2a0 Call Trace: <TASK> ? __warn+0x7e/0x120 ? rcu_nocb_rdp_deoffload+0x292/0x2a0 ? report_bug+0x18e/0x1a0 ? handle_bug+0x3d/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? rcu_nocb_rdp_deoffload+0x292/0x2a0 rcu_nocb_cpu_deoffload+0x70/0xa0 rcu_nocb_toggle+0x136/0x1c0 ? __pfx_rcu_nocb_toggle+0x10/0x10 kthread+0xd1/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2f/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> CPU0 CPU2 CPU3 //rcu_nocb_toggle //nocb_cb_wait //rcutorture // deoffload CPU1 // process CPU1's rdp rcu_barrier() rcu_segcblist_entrain() rcu_segcblist_add_len(1); // len == 2 // enqueue barrier // callback to CPU1's // rdp->cblist rcu_do_batch() // invoke CPU1's rdp->cblist // callback rcu_barrier_callback() rcu_barrier() mutex_lock(&rcu_state.barrier_mutex); // still see len == 2 // enqueue barrier callback // to CPU1's rdp->cblist rcu_segcblist_entrain() rcu_segcblist_add_len(1); // len == 3 // decrement len rcu_segcblist_add_len(-2); kthread_parkme() // CPU1's rdp->cblist len == 1 // Warn because there is // still a pending barrier // trigger warning WARN_ON_ONCE(rcu_segcblist_n_cbs(&rdp->cblist)); cpus_read_unlock(); // wait CPU1 to comes online and // invoke barrier callback on // CPU1 rdp's->cblist wait_for_completion(&rcu_state.barrier_completion); // deoffload CPU4 cpus_read_lock() rcu_barrier() mutex_lock(&rcu_state.barrier_mutex); // block on barrier_mutex // wait rcu_barrier() on // CPU3 to unlock barrier_mutex // but CPU3 unlock barrier_mutex // need to wait CPU1 comes online // when CPU1 going online will block on cpus_write_lock The above scenario will not only trigger a WARN_ON_ONCE(), but also trigger a deadlock. Thanks to nocb locking, a second racing rcu_barrier() on an offline CPU will either observe the decremented callback counter down to 0 and spare the callback enqueue, or rcuo will observe the new callback and keep rdp->nocb_cb_sleep to false. Therefore check rdp->nocb_cb_sleep before parking to make sure no further rcu_barrier() is waiting on the rdp.

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: bus: mhi: host: Fix race between unprepare and queue_buf A client driver may use mhi_unprepare_from_transfer() to quiesce incoming data during the client driver's tear down. The client driver might also be processing data at the same time, resulting in a call to mhi_queue_buf() which will invoke mhi_gen_tre(). If mhi_gen_tre() runs after mhi_unprepare_from_transfer() has torn down the channel, a panic will occur due to an invalid dereference leading to a page fault. This occurs because mhi_gen_tre() does not verify the channel state after locking it. Fix this by having mhi_gen_tre() confirm the channel state is valid, or return error to avoid accessing deinitialized data. [mani: added stable tag]

In the Linux kernel, the following vulnerability has been resolved: ath11k: fix netdev open race Make sure to allocate resources needed before registering the device. This specifically avoids having a racing open() trigger a BUG_ON() in mod_timer() when ath11k_mac_op_start() is called before the mon_reap_timer as been set up. I did not see this issue with next-20220310, but I hit it on every probe with next-20220511. Perhaps some timing changed in between. Here's the backtrace: [ 51.346947] kernel BUG at kernel/time/timer.c:990! [ 51.346958] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ... [ 51.578225] Call trace: [ 51.583293] __mod_timer+0x298/0x390 [ 51.589518] mod_timer+0x14/0x20 [ 51.595368] ath11k_mac_op_start+0x41c/0x4a0 [ath11k] [ 51.603165] drv_start+0x38/0x60 [mac80211] [ 51.610110] ieee80211_do_open+0x29c/0x7d0 [mac80211] [ 51.617945] ieee80211_open+0x60/0xb0 [mac80211] [ 51.625311] __dev_open+0x100/0x1c0 [ 51.631420] __dev_change_flags+0x194/0x210 [ 51.638214] dev_change_flags+0x24/0x70 [ 51.644646] do_setlink+0x228/0xdb0 [ 51.650723] __rtnl_newlink+0x460/0x830 [ 51.657162] rtnl_newlink+0x4c/0x80 [ 51.663229] rtnetlink_rcv_msg+0x124/0x390 [ 51.669917] netlink_rcv_skb+0x58/0x130 [ 51.676314] rtnetlink_rcv+0x18/0x30 [ 51.682460] netlink_unicast+0x250/0x310 [ 51.688960] netlink_sendmsg+0x19c/0x3e0 [ 51.695458] ____sys_sendmsg+0x220/0x290 [ 51.701938] ___sys_sendmsg+0x7c/0xc0 [ 51.708148] __sys_sendmsg+0x68/0xd0 [ 51.714254] __arm64_sys_sendmsg+0x28/0x40 [ 51.720900] invoke_syscall+0x48/0x120 Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3

In the Linux kernel, the following vulnerability has been resolved: platform/x86: lenovo-yoga-tab2-pro-1380-fastcharger: fix serdev race The yt2_1380_fc_serdev_probe() function calls devm_serdev_device_open() before setting the client ops via serdev_device_set_client_ops(). This ordering can trigger a NULL pointer dereference in the serdev controller's receive_buf handler, as it assumes serdev->ops is valid when SERPORT_ACTIVE is set. This is similar to the issue fixed in commit 5e700b384ec1 ("platform/chrome: cros_ec_uart: properly fix race condition") where devm_serdev_device_open() was called before fully initializing the device. Fix the race by ensuring client ops are set before enabling the port via devm_serdev_device_open(). Note, serdev_device_set_baudrate() and serdev_device_set_flow_control() calls should be after the devm_serdev_device_open() call.