In the Linux kernel, the following vulnerability has been resolved: um: work around sched_yield not yielding in time-travel mode sched_yield by a userspace may not actually cause scheduling in time-travel mode as no time has passed. In the case seen it appears to be a badly implemented userspace spinlock in ASAN. Unfortunately, with time-travel it causes an extreme slowdown or even deadlock depending on the kernel configuration (CONFIG_UML_MAX_USERSPACE_ITERATIONS). Work around it by accounting time to the process whenever it executes a sched_yield syscall.

In the Linux kernel, the following vulnerability has been resolved: IB/mlx5: Fix potential deadlock in MR deregistration The issue arises when kzalloc() is invoked while holding umem_mutex or any other lock acquired under umem_mutex. This is problematic because kzalloc() can trigger fs_reclaim_aqcuire(), which may, in turn, invoke mmu_notifier_invalidate_range_start(). This function can lead to mlx5_ib_invalidate_range(), which attempts to acquire umem_mutex again, resulting in a deadlock. The problematic flow: CPU0 | CPU1 ---------------------------------------|------------------------------------------------ mlx5_ib_dereg_mr() | → revoke_mr() | → mutex_lock(&umem_odp->umem_mutex) | | mlx5_mkey_cache_init() | → mutex_lock(&dev->cache.rb_lock) | → mlx5r_cache_create_ent_locked() | → kzalloc(GFP_KERNEL) | → fs_reclaim() | → mmu_notifier_invalidate_range_start() | → mlx5_ib_invalidate_range() | → mutex_lock(&umem_odp->umem_mutex) → cache_ent_find_and_store() | → mutex_lock(&dev->cache.rb_lock) | Additionally, when kzalloc() is called from within cache_ent_find_and_store(), we encounter the same deadlock due to re-acquisition of umem_mutex. Solve by releasing umem_mutex in dereg_mr() after umr_revoke_mr() and before acquiring rb_lock. This ensures that we don't hold umem_mutex while performing memory allocations that could trigger the reclaim path. This change prevents the deadlock by ensuring proper lock ordering and avoiding holding locks during memory allocation operations that could trigger the reclaim path. The following lockdep warning demonstrates the deadlock: python3/20557 is trying to acquire lock: ffff888387542128 (&umem_odp->umem_mutex){+.+.}-{4:4}, at: mlx5_ib_invalidate_range+0x5b/0x550 [mlx5_ib] but task is already holding lock: ffffffff82f6b840 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: unmap_vmas+0x7b/0x1a0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}: fs_reclaim_acquire+0x60/0xd0 mem_cgroup_css_alloc+0x6f/0x9b0 cgroup_init_subsys+0xa4/0x240 cgroup_init+0x1c8/0x510 start_kernel+0x747/0x760 x86_64_start_reservations+0x25/0x30 x86_64_start_kernel+0x73/0x80 common_startup_64+0x129/0x138 -> #2 (fs_reclaim){+.+.}-{0:0}: fs_reclaim_acquire+0x91/0xd0 __kmalloc_cache_noprof+0x4d/0x4c0 mlx5r_cache_create_ent_locked+0x75/0x620 [mlx5_ib] mlx5_mkey_cache_init+0x186/0x360 [mlx5_ib] mlx5_ib_stage_post_ib_reg_umr_init+0x3c/0x60 [mlx5_ib] __mlx5_ib_add+0x4b/0x190 [mlx5_ib] mlx5r_probe+0xd9/0x320 [mlx5_ib] auxiliary_bus_probe+0x42/0x70 really_probe+0xdb/0x360 __driver_probe_device+0x8f/0x130 driver_probe_device+0x1f/0xb0 __driver_attach+0xd4/0x1f0 bus_for_each_dev+0x79/0xd0 bus_add_driver+0xf0/0x200 driver_register+0x6e/0xc0 __auxiliary_driver_register+0x6a/0xc0 do_one_initcall+0x5e/0x390 do_init_module+0x88/0x240 init_module_from_file+0x85/0xc0 idempotent_init_module+0x104/0x300 __x64_sys_finit_module+0x68/0xc0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 -> #1 (&dev->cache.rb_lock){+.+.}-{4:4}: __mutex_lock+0x98/0xf10 __mlx5_ib_dereg_mr+0x6f2/0x890 [mlx5_ib] mlx5_ib_dereg_mr+0x21/0x110 [mlx5_ib] ib_dereg_mr_user+0x85/0x1f0 [ib_core] ---truncated---

In the Linux kernel, the following vulnerability has been resolved: usb: typec: displayport: Fix potential deadlock The deadlock can occur due to a recursive lock acquisition of `cros_typec_altmode_data::mutex`. The call chain is as follows: 1. cros_typec_altmode_work() acquires the mutex 2. typec_altmode_vdm() -> dp_altmode_vdm() -> 3. typec_altmode_exit() -> cros_typec_altmode_exit() 4. cros_typec_altmode_exit() attempts to acquire the mutex again To prevent this, defer the `typec_altmode_exit()` call by scheduling it rather than calling it directly from within the mutex-protected context.

In the Linux kernel, the following vulnerability has been resolved: e1000: Move cancel_work_sync to avoid deadlock Previously, e1000_down called cancel_work_sync for the e1000 reset task (via e1000_down_and_stop), which takes RTNL. As reported by users and syzbot, a deadlock is possible in the following scenario: CPU 0: - RTNL is held - e1000_close - e1000_down - cancel_work_sync (cancel / wait for e1000_reset_task()) CPU 1: - process_one_work - e1000_reset_task - take RTNL To remedy this, avoid calling cancel_work_sync from e1000_down (e1000_reset_task does nothing if the device is down anyway). Instead, call cancel_work_sync for e1000_reset_task when the device is being removed.

In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: displayport: Fix deadlock This patch introduces the ucsi_con_mutex_lock / ucsi_con_mutex_unlock functions to the UCSI driver. ucsi_con_mutex_lock ensures the connector mutex is only locked if a connection is established and the partner pointer is valid. This resolves a deadlock scenario where ucsi_displayport_remove_partner holds con->mutex waiting for dp_altmode_work to complete while dp_altmode_work attempts to acquire it.

In the Linux kernel, the following vulnerability has been resolved: accel/ivpu: Fix locking order in ivpu_job_submit Fix deadlock in job submission and abort handling. When a thread aborts currently executing jobs due to a fault, it first locks the global lock protecting submitted_jobs (#1). After the last job is destroyed, it proceeds to release the related context and locks file_priv (#2). Meanwhile, in the job submission thread, the file_priv lock (#2) is taken first, and then the submitted_jobs lock (#1) is obtained when a job is added to the submitted jobs list. CPU0 CPU1 ---- ---- (for example due to a fault) (jobs submissions keep coming) lock(&vdev->submitted_jobs_lock) #1 ivpu_jobs_abort_all() job_destroy() lock(&file_priv->lock) #2 lock(&vdev->submitted_jobs_lock) #1 file_priv_release() lock(&vdev->context_list_lock) lock(&file_priv->lock) #2 This order of locking causes a deadlock. To resolve this issue, change the order of locking in ivpu_job_submit().

In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: fix region locking in hash types Region locking introduced in v5.6-rc4 contained three macros to handle the region locks: ahash_bucket_start(), ahash_bucket_end() which gave back the start and end hash bucket values belonging to a given region lock and ahash_region() which should give back the region lock belonging to a given hash bucket. The latter was incorrect which can lead to a race condition between the garbage collector and adding new elements when a hash type of set is defined with timeouts.

In the Linux kernel, the following vulnerability has been resolved: drm/xe/userptr: fix notifier vs folio deadlock User is reporting what smells like notifier vs folio deadlock, where migrate_pages_batch() on core kernel side is holding folio lock(s) and then interacting with the mappings of it, however those mappings are tied to some userptr, which means calling into the notifier callback and grabbing the notifier lock. With perfect timing it looks possible that the pages we pulled from the hmm fault can get sniped by migrate_pages_batch() at the same time that we are holding the notifier lock to mark the pages as accessed/dirty, but at this point we also want to grab the folio locks(s) to mark them as dirty, but if they are contended from notifier/migrate_pages_batch side then we deadlock since folio lock won't be dropped until we drop the notifier lock. Fortunately the mark_page_accessed/dirty is not really needed in the first place it seems and should have already been done by hmm fault, so just remove it. (cherry picked from commit bd7c0cb695e87c0e43247be8196b4919edbe0e85)

In the Linux kernel, the following vulnerability has been resolved: virtio-net: fix recursived rtnl_lock() during probe() The deadlock appears in a stack trace like: virtnet_probe() rtnl_lock() virtio_config_changed_work() netdev_notify_peers() rtnl_lock() It happens if the VMM sends a VIRTIO_NET_S_ANNOUNCE request while the virtio-net driver is still probing. The config_work in probe() will get scheduled until virtnet_open() enables the config change notification via virtio_config_driver_enable().

In the Linux kernel, the following vulnerability has been resolved: accel/ivpu: Fix PM related deadlocks in MS IOCTLs Prevent runtime resume/suspend while MS IOCTLs are in progress. Failed suspend will call ivpu_ms_cleanup() that would try to acquire file_priv->ms_lock, which is already held by the IOCTLs.

In the Linux kernel, the following vulnerability has been resolved: KVM: Allow CPU to reschedule while setting per-page memory attributes When running an SEV-SNP guest with a sufficiently large amount of memory (1TB+), the host can experience CPU soft lockups when running an operation in kvm_vm_set_mem_attributes() to set memory attributes on the whole range of guest memory. watchdog: BUG: soft lockup - CPU#8 stuck for 26s! [qemu-kvm:6372] CPU: 8 UID: 0 PID: 6372 Comm: qemu-kvm Kdump: loaded Not tainted 6.15.0-rc7.20250520.el9uek.rc1.x86_64 #1 PREEMPT(voluntary) Hardware name: Oracle Corporation ORACLE SERVER E4-2c/Asm,MB Tray,2U,E4-2c, BIOS 78016600 11/13/2024 RIP: 0010:xas_create+0x78/0x1f0 Code: 00 00 00 41 80 fc 01 0f 84 82 00 00 00 ba 06 00 00 00 bd 06 00 00 00 49 8b 45 08 4d 8d 65 08 41 39 d6 73 20 83 ed 06 48 85 c0 <74> 67 48 89 c2 83 e2 03 48 83 fa 02 75 0c 48 3d 00 10 00 00 0f 87 RSP: 0018:ffffad890a34b940 EFLAGS: 00000286 RAX: ffff96f30b261daa RBX: ffffad890a34b9c8 RCX: 0000000000000000 RDX: 000000000000001e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffad890a356868 R13: ffffad890a356860 R14: 0000000000000000 R15: ffffad890a356868 FS: 00007f5578a2a400(0000) GS:ffff97ed317e1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f015c70fb18 CR3: 00000001109fd006 CR4: 0000000000f70ef0 PKRU: 55555554 Call Trace: <TASK> xas_store+0x58/0x630 __xa_store+0xa5/0x130 xa_store+0x2c/0x50 kvm_vm_set_mem_attributes+0x343/0x710 [kvm] kvm_vm_ioctl+0x796/0xab0 [kvm] __x64_sys_ioctl+0xa3/0xd0 do_syscall_64+0x8c/0x7a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f5578d031bb Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 2d 4c 0f 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe0a742b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000004020aed2 RCX: 00007f5578d031bb RDX: 00007ffe0a742c80 RSI: 000000004020aed2 RDI: 000000000000000b RBP: 0000010000000000 R08: 0000010000000000 R09: 0000017680000000 R10: 0000000000000080 R11: 0000000000000246 R12: 00005575e5f95120 R13: 00007ffe0a742c80 R14: 0000000000000008 R15: 00005575e5f961e0 While looping through the range of memory setting the attributes, call cond_resched() to give the scheduler a chance to run a higher priority task on the runqueue if necessary and avoid staying in kernel mode long enough to trigger the lockup.

In the Linux kernel, the following vulnerability has been resolved: iio: light: opt3001: fix deadlock due to concurrent flag access The threaded IRQ function in this driver is reading the flag twice: once to lock a mutex and once to unlock it. Even though the code setting the flag is designed to prevent it, there are subtle cases where the flag could be true at the mutex_lock stage and false at the mutex_unlock stage. This results in the mutex not being unlocked, resulting in a deadlock. Fix it by making the opt3001_irq() code generally more robust, reading the flag into a variable and using the variable value at both stages.

In the Linux kernel, the following vulnerability has been resolved: __legitimize_mnt(): check for MNT_SYNC_UMOUNT should be under mount_lock ... or we risk stealing final mntput from sync umount - raising mnt_count after umount(2) has verified that victim is not busy, but before it has set MNT_SYNC_UMOUNT; in that case __legitimize_mnt() doesn't see that it's safe to quietly undo mnt_count increment and leaves dropping the reference to caller, where it'll be a full-blown mntput(). Check under mount_lock is needed; leaving the current one done before taking that makes no sense - it's nowhere near common enough to bother with.

In the Linux kernel, the following vulnerability has been resolved: jfs: Prevent copying of nlink with value 0 from disk inode syzbot report a deadlock in diFree. [1] When calling "ioctl$LOOP_SET_STATUS64", the offset value passed in is 4, which does not match the mounted loop device, causing the mapping of the mounted loop device to be invalidated. When creating the directory and creating the inode of iag in diReadSpecial(), read the page of fixed disk inode (AIT) in raw mode in read_metapage(), the metapage data it returns is corrupted, which causes the nlink value of 0 to be assigned to the iag inode when executing copy_from_dinode(), which ultimately causes a deadlock when entering diFree(). To avoid this, first check the nlink value of dinode before setting iag inode. [1] WARNING: possible recursive locking detected 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0 Not tainted -------------------------------------------- syz-executor301/5309 is trying to acquire lock: ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889 but task is already holding lock: ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(imap->im_aglock[index])); lock(&(imap->im_aglock[index])); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor301/5309: #0: ffff8880422a4420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline] #1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:4026 #2: ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630 #3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2460 [inline] #3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline] #3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocAG+0x4b7/0x1e50 fs/jfs/jfs_imap.c:1669 #4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2477 [inline] #4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline] #4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocAG+0x869/0x1e50 fs/jfs/jfs_imap.c:1669 stack backtrace: CPU: 0 UID: 0 PID: 5309 Comm: syz-executor301 Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037 check_deadlock kernel/locking/lockdep.c:3089 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889 jfs_evict_inode+0x32d/0x440 fs/jfs/inode.c:156 evict+0x4e8/0x9b0 fs/inode.c:725 diFreeSpecial fs/jfs/jfs_imap.c:552 [inline] duplicateIXtree+0x3c6/0x550 fs/jfs/jfs_imap.c:3022 diNewIAG fs/jfs/jfs_imap.c:2597 [inline] diAllocExt fs/jfs/jfs_imap.c:1905 [inline] diAllocAG+0x17dc/0x1e50 fs/jfs/jfs_imap.c:1669 diAlloc+0x1d2/0x1630 fs/jfs/jfs_imap.c:1590 ialloc+0x8f/0x900 fs/jfs/jfs_inode.c:56 jfs_mkdir+0x1c5/0xba0 fs/jfs/namei.c:225 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257 do_mkdirat+0x264/0x3a0 fs/namei.c:4280 __do_sys_mkdirat fs/namei.c:4295 [inline] __se_sys_mkdirat fs/namei.c:4293 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293 do_syscall_x64 arch/x86/en ---truncated---

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential deadlock when reconnecting channels Fix cifs_signal_cifsd_for_reconnect() to take the correct lock order and prevent the following deadlock from happening ====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc3-build2+ #1301 Tainted: G S W ------------------------------------------------------ cifsd/6055 is trying to acquire lock: ffff88810ad56038 (&tcp_ses->srv_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x134/0x200 but task is already holding lock: ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ret_buf->chan_lock){+.+.}-{3:3}: validate_chain+0x1cf/0x270 __lock_acquire+0x60e/0x780 lock_acquire.part.0+0xb4/0x1f0 _raw_spin_lock+0x2f/0x40 cifs_setup_session+0x81/0x4b0 cifs_get_smb_ses+0x771/0x900 cifs_mount_get_session+0x7e/0x170 cifs_mount+0x92/0x2d0 cifs_smb3_do_mount+0x161/0x460 smb3_get_tree+0x55/0x90 vfs_get_tree+0x46/0x180 do_new_mount+0x1b0/0x2e0 path_mount+0x6ee/0x740 do_mount+0x98/0xe0 __do_sys_mount+0x148/0x180 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&ret_buf->ses_lock){+.+.}-{3:3}: validate_chain+0x1cf/0x270 __lock_acquire+0x60e/0x780 lock_acquire.part.0+0xb4/0x1f0 _raw_spin_lock+0x2f/0x40 cifs_match_super+0x101/0x320 sget+0xab/0x270 cifs_smb3_do_mount+0x1e0/0x460 smb3_get_tree+0x55/0x90 vfs_get_tree+0x46/0x180 do_new_mount+0x1b0/0x2e0 path_mount+0x6ee/0x740 do_mount+0x98/0xe0 __do_sys_mount+0x148/0x180 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (&tcp_ses->srv_lock){+.+.}-{3:3}: check_noncircular+0x95/0xc0 check_prev_add+0x115/0x2f0 validate_chain+0x1cf/0x270 __lock_acquire+0x60e/0x780 lock_acquire.part.0+0xb4/0x1f0 _raw_spin_lock+0x2f/0x40 cifs_signal_cifsd_for_reconnect+0x134/0x200 __cifs_reconnect+0x8f/0x500 cifs_handle_standard+0x112/0x280 cifs_demultiplex_thread+0x64d/0xbc0 kthread+0x2f7/0x310 ret_from_fork+0x2a/0x230 ret_from_fork_asm+0x1a/0x30 other info that might help us debug this: Chain exists of: &tcp_ses->srv_lock --> &ret_buf->ses_lock --> &ret_buf->chan_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ret_buf->chan_lock); lock(&ret_buf->ses_lock); lock(&ret_buf->chan_lock); lock(&tcp_ses->srv_lock); *** DEADLOCK *** 3 locks held by cifsd/6055: #0: ffffffff857de398 (&cifs_tcp_ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x7b/0x200 #1: ffff888119c64060 (&ret_buf->ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x9c/0x200 #2: ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200

In the Linux kernel, the following vulnerability has been resolved: hfsplus: remove mutex_lock check in hfsplus_free_extents Syzbot reported an issue in hfsplus filesystem: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 4400 at fs/hfsplus/extents.c:346 hfsplus_free_extents+0x700/0xad0 Call Trace: <TASK> hfsplus_file_truncate+0x768/0xbb0 fs/hfsplus/extents.c:606 hfsplus_write_begin+0xc2/0xd0 fs/hfsplus/inode.c:56 cont_expand_zero fs/buffer.c:2383 [inline] cont_write_begin+0x2cf/0x860 fs/buffer.c:2446 hfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52 generic_cont_expand_simple+0x151/0x250 fs/buffer.c:2347 hfsplus_setattr+0x168/0x280 fs/hfsplus/inode.c:263 notify_change+0xe38/0x10f0 fs/attr.c:420 do_truncate+0x1fb/0x2e0 fs/open.c:65 do_sys_ftruncate+0x2eb/0x380 fs/open.c:193 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd To avoid deadlock, Commit 31651c607151 ("hfsplus: avoid deadlock on file truncation") unlock extree before hfsplus_free_extents(), and add check wheather extree is locked in hfsplus_free_extents(). However, when operations such as hfsplus_file_release, hfsplus_setattr, hfsplus_unlink, and hfsplus_get_block are executed concurrently in different files, it is very likely to trigger the WARN_ON, which will lead syzbot and xfstest to consider it as an abnormality. The comment above this warning also describes one of the easy triggering situations, which can easily trigger and cause xfstest&syzbot to report errors. [task A] [task B] ->hfsplus_file_release ->hfsplus_file_truncate ->hfs_find_init ->mutex_lock ->mutex_unlock ->hfsplus_write_begin ->hfsplus_get_block ->hfsplus_file_extend ->hfsplus_ext_read_extent ->hfs_find_init ->mutex_lock ->hfsplus_free_extents WARN_ON(mutex_is_locked) !!! Several threads could try to lock the shared extents tree. And warning can be triggered in one thread when another thread has locked the tree. This is the wrong behavior of the code and we need to remove the warning.

In the Linux kernel, the following vulnerability has been resolved: iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_tagged_fifo Prevent st_lsm6dsx_read_tagged_fifo from falling in an infinite loop in case pattern_len is equal to zero and the device FIFO is not empty.

In the Linux kernel, the following vulnerability has been resolved: af_packet: move notifier's packet_dev_mc out of rcu critical section Syzkaller reports the following issue: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:578 __mutex_lock+0x106/0xe80 kernel/locking/mutex.c:746 team_change_rx_flags+0x38/0x220 drivers/net/team/team_core.c:1781 dev_change_rx_flags net/core/dev.c:9145 [inline] __dev_set_promiscuity+0x3f8/0x590 net/core/dev.c:9189 netif_set_promiscuity+0x50/0xe0 net/core/dev.c:9201 dev_set_promiscuity+0x126/0x260 net/core/dev_api.c:286 packet_dev_mc net/packet/af_packet.c:3698 [inline] packet_dev_mclist_delete net/packet/af_packet.c:3722 [inline] packet_notifier+0x292/0xa60 net/packet/af_packet.c:4247 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] unregister_netdevice_many_notify+0x15d8/0x2330 net/core/dev.c:11972 rtnl_delete_link net/core/rtnetlink.c:3522 [inline] rtnl_dellink+0x488/0x710 net/core/rtnetlink.c:3564 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6955 netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534 Calling `PACKET_ADD_MEMBERSHIP` on an ops-locked device can trigger the `NETDEV_UNREGISTER` notifier, which may require disabling promiscuous and/or allmulti mode. Both of these operations require acquiring the netdev instance lock. Move the call to `packet_dev_mc` outside of the RCU critical section. The `mclist` modifications (add, del, flush, unregister) are protected by the RTNL, not the RCU. The RCU only protects the `sklist` and its associated `sks`. The delayed operation on the `mclist` entry remains within the RTNL.

In the Linux kernel, the following vulnerability has been resolved: ftrace: Add cond_resched() to ftrace_graph_set_hash() When the kernel contains a large number of functions that can be traced, the loop in ftrace_graph_set_hash() may take a lot of time to execute. This may trigger the softlockup watchdog. Add cond_resched() within the loop to allow the kernel to remain responsive even when processing a large number of functions. This matches the cond_resched() that is used in other locations of the code that iterates over all functions that can be traced.

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Convert spinlock to mutex to lock evl workqueue drain_workqueue() cannot be called safely in a spinlocked context due to possible task rescheduling. In the multi-task scenario, calling queue_work() while drain_workqueue() will lead to a Call Trace as pushing a work on a draining workqueue is not permitted in spinlocked context. Call Trace: <TASK> ? __warn+0x7d/0x140 ? __queue_work+0x2b2/0x440 ? report_bug+0x1f8/0x200 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? __queue_work+0x2b2/0x440 queue_work_on+0x28/0x30 idxd_misc_thread+0x303/0x5a0 [idxd] ? __schedule+0x369/0xb40 ? __pfx_irq_thread_fn+0x10/0x10 ? irq_thread+0xbc/0x1b0 irq_thread_fn+0x21/0x70 irq_thread+0x102/0x1b0 ? preempt_count_add+0x74/0xa0 ? __pfx_irq_thread_dtor+0x10/0x10 ? __pfx_irq_thread+0x10/0x10 kthread+0x103/0x140 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> The current implementation uses a spinlock to protect event log workqueue and will lead to the Call Trace due to potential task rescheduling. To address the locking issue, convert the spinlock to mutex, allowing the drain_workqueue() to be called in a safe mutex-locked context. This change ensures proper synchronization when accessing the event log workqueue, preventing potential Call Trace and improving the overall robustness of the code.

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix deadlock between rcu_tasks_trace and event_mutex. Fix the following deadlock: CPU A _free_event() perf_kprobe_destroy() mutex_lock(&event_mutex) perf_trace_event_unreg() synchronize_rcu_tasks_trace() There are several paths where _free_event() grabs event_mutex and calls sync_rcu_tasks_trace. Above is one such case. CPU B bpf_prog_test_run_syscall() rcu_read_lock_trace() bpf_prog_run_pin_on_cpu() bpf_prog_load() bpf_tracing_func_proto() trace_set_clr_event() mutex_lock(&event_mutex) Delegate trace_set_clr_event() to workqueue to avoid such lock dependency.

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: Add missing lock in cfg80211_check_and_end_cac() Callers of wdev_chandef() must hold the wiphy mutex. But the worker cfg80211_propagate_cac_done_wk() never takes the lock. Which triggers the warning below with the mesh_peer_connected_dfs test from hostapd and not (yet) released mac80211 code changes: WARNING: CPU: 0 PID: 495 at net/wireless/chan.c:1552 wdev_chandef+0x60/0x165 Modules linked in: CPU: 0 UID: 0 PID: 495 Comm: kworker/u4:2 Not tainted 6.14.0-rc5-wt-g03960e6f9d47 #33 13c287eeabfe1efea01c0bcc863723ab082e17cf Workqueue: cfg80211 cfg80211_propagate_cac_done_wk Stack: 00000000 00000001 ffffff00 6093267c 00000000 6002ec30 6d577c50 60037608 00000000 67e8d108 6063717b 00000000 Call Trace: [<6002ec30>] ? _printk+0x0/0x98 [<6003c2b3>] show_stack+0x10e/0x11a [<6002ec30>] ? _printk+0x0/0x98 [<60037608>] dump_stack_lvl+0x71/0xb8 [<6063717b>] ? wdev_chandef+0x60/0x165 [<6003766d>] dump_stack+0x1e/0x20 [<6005d1b7>] __warn+0x101/0x20f [<6005d3a8>] warn_slowpath_fmt+0xe3/0x15d [<600b0c5c>] ? mark_lock.part.0+0x0/0x4ec [<60751191>] ? __this_cpu_preempt_check+0x0/0x16 [<600b11a2>] ? mark_held_locks+0x5a/0x6e [<6005d2c5>] ? warn_slowpath_fmt+0x0/0x15d [<60052e53>] ? unblock_signals+0x3a/0xe7 [<60052f2d>] ? um_set_signals+0x2d/0x43 [<60751191>] ? __this_cpu_preempt_check+0x0/0x16 [<607508b2>] ? lock_is_held_type+0x207/0x21f [<6063717b>] wdev_chandef+0x60/0x165 [<605f89b4>] regulatory_propagate_dfs_state+0x247/0x43f [<60052f00>] ? um_set_signals+0x0/0x43 [<605e6bfd>] cfg80211_propagate_cac_done_wk+0x3a/0x4a [<6007e460>] process_scheduled_works+0x3bc/0x60e [<6007d0ec>] ? move_linked_works+0x4d/0x81 [<6007d120>] ? assign_work+0x0/0xaa [<6007f81f>] worker_thread+0x220/0x2dc [<600786ef>] ? set_pf_worker+0x0/0x57 [<60087c96>] ? to_kthread+0x0/0x43 [<6008ab3c>] kthread+0x2d3/0x2e2 [<6007f5ff>] ? worker_thread+0x0/0x2dc [<6006c05b>] ? calculate_sigpending+0x0/0x56 [<6003b37d>] new_thread_handler+0x4a/0x64 irq event stamp: 614611 hardirqs last enabled at (614621): [<00000000600bc96b>] __up_console_sem+0x82/0xaf hardirqs last disabled at (614630): [<00000000600bc92c>] __up_console_sem+0x43/0xaf softirqs last enabled at (614268): [<00000000606c55c6>] __ieee80211_wake_queue+0x933/0x985 softirqs last disabled at (614266): [<00000000606c52d6>] __ieee80211_wake_queue+0x643/0x985

In the Linux kernel, the following vulnerability has been resolved: net: cadence: macb: Fix a possible deadlock in macb_halt_tx. There is a situation where after THALT is set high, TGO stays high as well. Because jiffies are never updated, as we are in a context with interrupts disabled, we never exit that loop and have a deadlock. That deadlock was noticed on a sama5d4 device that stayed locked for days. Use retries instead of jiffies so that the timeout really works and we do not have a deadlock anymore.

In the Linux kernel, the following vulnerability has been resolved: drm/scheduler: signal scheduled fence when kill job When an entity from application B is killed, drm_sched_entity_kill() removes all jobs belonging to that entity through drm_sched_entity_kill_jobs_work(). If application A's job depends on a scheduled fence from application B's job, and that fence is not properly signaled during the killing process, application A's dependency cannot be cleared. This leads to application A hanging indefinitely while waiting for a dependency that will never be resolved. Fix this issue by ensuring that scheduled fences are properly signaled when an entity is killed, allowing dependent applications to continue execution.

In the Linux kernel, the following vulnerability has been resolved: block: don't use submit_bio_noacct_nocheck in blk_zone_wplug_bio_work Bios queued up in the zone write plug have already gone through all all preparation in the submit_bio path, including the freeze protection. Submitting them through submit_bio_noacct_nocheck duplicates the work and can can cause deadlocks when freezing a queue with pending bio write plugs. Go straight to ->submit_bio or blk_mq_submit_bio to bypass the superfluous extra freeze protection and checks.

In the Linux kernel, the following vulnerability has been resolved: mm/shmem, swap: fix softlockup with mTHP swapin Following softlockup can be easily reproduced on my test machine with: echo always > /sys/kernel/mm/transparent_hugepage/hugepages-64kB/enabled swapon /dev/zram0 # zram0 is a 48G swap device mkdir -p /sys/fs/cgroup/memory/test echo 1G > /sys/fs/cgroup/test/memory.max echo $BASHPID > /sys/fs/cgroup/test/cgroup.procs while true; do dd if=/dev/zero of=/tmp/test.img bs=1M count=5120 cat /tmp/test.img > /dev/null rm /tmp/test.img done Then after a while: watchdog: BUG: soft lockup - CPU#0 stuck for 763s! [cat:5787] Modules linked in: zram virtiofs CPU: 0 UID: 0 PID: 5787 Comm: cat Kdump: loaded Tainted: G L 6.15.0.orig-gf3021d9246bc-dirty #118 PREEMPT(voluntary)· Tainted: [L]=SOFTLOCKUP Hardware name: Red Hat KVM/RHEL-AV, BIOS 0.0.0 02/06/2015 RIP: 0010:mpol_shared_policy_lookup+0xd/0x70 Code: e9 b8 b4 ff ff 31 c0 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 0f 1f 44 00 00 41 54 55 53 <48> 8b 1f 48 85 db 74 41 4c 8d 67 08 48 89 fb 48 89 f5 4c 89 e7 e8 RSP: 0018:ffffc90002b1fc28 EFLAGS: 00000202 RAX: 00000000001c20ca RBX: 0000000000724e1e RCX: 0000000000000001 RDX: ffff888118e214c8 RSI: 0000000000057d42 RDI: ffff888118e21518 RBP: 000000000002bec8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000bf4 R11: 0000000000000000 R12: 0000000000000001 R13: 00000000001c20ca R14: 00000000001c20ca R15: 0000000000000000 FS: 00007f03f995c740(0000) GS:ffff88a07ad9a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f03f98f1000 CR3: 0000000144626004 CR4: 0000000000770eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> shmem_alloc_folio+0x31/0xc0 shmem_swapin_folio+0x309/0xcf0 ? filemap_get_entry+0x117/0x1e0 ? xas_load+0xd/0xb0 ? filemap_get_entry+0x101/0x1e0 shmem_get_folio_gfp+0x2ed/0x5b0 shmem_file_read_iter+0x7f/0x2e0 vfs_read+0x252/0x330 ksys_read+0x68/0xf0 do_syscall_64+0x4c/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f03f9a46991 Code: 00 48 8b 15 81 14 10 00 f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 20 ad 01 00 f3 0f 1e fa 80 3d 35 97 10 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 4f c3 66 0f 1f 44 00 00 55 48 89 e5 48 83 ec RSP: 002b:00007fff3c52bd28 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007f03f9a46991 RDX: 0000000000040000 RSI: 00007f03f98ba000 RDI: 0000000000000003 RBP: 00007fff3c52bd50 R08: 0000000000000000 R09: 00007f03f9b9a380 R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000040000 R13: 00007f03f98ba000 R14: 0000000000000003 R15: 0000000000000000 </TASK> The reason is simple, readahead brought some order 0 folio in swap cache, and the swapin mTHP folio being allocated is in conflict with it, so swapcache_prepare fails and causes shmem_swap_alloc_folio to return -EEXIST, and shmem simply retries again and again causing this loop. Fix it by applying a similar fix for anon mTHP swapin. The performance change is very slight, time of swapin 10g zero folios with shmem (test for 12 times): Before: 2.47s After: 2.48s [kasong@tencent.com: add comment]

In the Linux kernel, the following vulnerability has been resolved: Input: gpio-keys - fix a sleep while atomic with PREEMPT_RT When enabling PREEMPT_RT, the gpio_keys_irq_timer() callback runs in hard irq context, but the input_event() takes a spin_lock, which isn't allowed there as it is converted to a rt_spin_lock(). [ 4054.289999] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 [ 4054.290028] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/0 ... [ 4054.290195] __might_resched+0x13c/0x1f4 [ 4054.290209] rt_spin_lock+0x54/0x11c [ 4054.290219] input_event+0x48/0x80 [ 4054.290230] gpio_keys_irq_timer+0x4c/0x78 [ 4054.290243] __hrtimer_run_queues+0x1a4/0x438 [ 4054.290257] hrtimer_interrupt+0xe4/0x240 [ 4054.290269] arch_timer_handler_phys+0x2c/0x44 [ 4054.290283] handle_percpu_devid_irq+0x8c/0x14c [ 4054.290297] handle_irq_desc+0x40/0x58 [ 4054.290307] generic_handle_domain_irq+0x1c/0x28 [ 4054.290316] gic_handle_irq+0x44/0xcc Considering the gpio_keys_irq_isr() can run in any context, e.g. it can be threaded, it seems there's no point in requesting the timer isr to run in hard irq context. Relax the hrtimer not to use the hard context.

In the Linux kernel, the following vulnerability has been resolved: accel/ivpu: Fix deadlock in ivpu_ms_cleanup() Fix deadlock in ivpu_ms_cleanup() by preventing runtime resume after file_priv->ms_lock is acquired. During a failure in runtime resume, a cold boot is executed, which calls ivpu_ms_cleanup_all(). This function calls ivpu_ms_cleanup() that acquires file_priv->ms_lock and causes the deadlock.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix WARNING "do not call blocking ops when !TASK_RUNNING" wait_event_timeout() will set the state of the current task to TASK_UNINTERRUPTIBLE, before doing the condition check. This means that ksmbd_durable_scavenger_alive() will try to acquire the mutex while already in a sleeping state. The scheduler warns us by giving the following warning: do not call blocking ops when !TASK_RUNNING; state=2 set at [<0000000061515a6f>] prepare_to_wait_event+0x9f/0x6c0 WARNING: CPU: 2 PID: 4147 at kernel/sched/core.c:10099 __might_sleep+0x12f/0x160 mutex lock is not needed in ksmbd_durable_scavenger_alive().

In the Linux kernel, the following vulnerability has been resolved: team: prevent adding a device which is already a team device lower Prevent adding a device which is already a team device lower, e.g. adding veth0 if vlan1 was already added and veth0 is a lower of vlan1. This is not useful in practice and can lead to recursive locking: $ ip link add veth0 type veth peer name veth1 $ ip link set veth0 up $ ip link set veth1 up $ ip link add link veth0 name veth0.1 type vlan protocol 802.1Q id 1 $ ip link add team0 type team $ ip link set veth0.1 down $ ip link set veth0.1 master team0 team0: Port device veth0.1 added $ ip link set veth0 down $ ip link set veth0 master team0 ============================================ WARNING: possible recursive locking detected 6.13.0-rc2-virtme-00441-ga14a429069bb #46 Not tainted -------------------------------------------- ip/7684 is trying to acquire lock: ffff888016848e00 (team->team_lock_key){+.+.}-{4:4}, at: team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) but task is already holding lock: ffff888016848e00 (team->team_lock_key){+.+.}-{4:4}, at: team_add_slave (drivers/net/team/team_core.c:1147 drivers/net/team/team_core.c:1977) other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(team->team_lock_key); lock(team->team_lock_key); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by ip/7684: stack backtrace: CPU: 3 UID: 0 PID: 7684 Comm: ip Not tainted 6.13.0-rc2-virtme-00441-ga14a429069bb #46 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:122) print_deadlock_bug.cold (kernel/locking/lockdep.c:3040) __lock_acquire (kernel/locking/lockdep.c:3893 kernel/locking/lockdep.c:5226) ? netlink_broadcast_filtered (net/netlink/af_netlink.c:1548) lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851) ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 2)) ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) ? lock_acquire (kernel/locking/lockdep.c:5822) ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) __mutex_lock (kernel/locking/mutex.c:587 kernel/locking/mutex.c:735) ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) ? fib_sync_up (net/ipv4/fib_semantics.c:2167) ? team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) team_device_event (drivers/net/team/team_core.c:2928 drivers/net/team/team_core.c:2951 drivers/net/team/team_core.c:2973) notifier_call_chain (kernel/notifier.c:85) call_netdevice_notifiers_info (net/core/dev.c:1996) __dev_notify_flags (net/core/dev.c:8993) ? __dev_change_flags (net/core/dev.c:8975) dev_change_flags (net/core/dev.c:9027) vlan_device_event (net/8021q/vlan.c:85 net/8021q/vlan.c:470) ? br_device_event (net/bridge/br.c:143) notifier_call_chain (kernel/notifier.c:85) call_netdevice_notifiers_info (net/core/dev.c:1996) dev_open (net/core/dev.c:1519 net/core/dev.c:1505) team_add_slave (drivers/net/team/team_core.c:1219 drivers/net/team/team_core.c:1977) ? __pfx_team_add_slave (drivers/net/team/team_core.c:1972) do_set_master (net/core/rtnetlink.c:2917) do_setlink.isra.0 (net/core/rtnetlink.c:3117)

In the Linux kernel, the following vulnerability has been resolved: firmware: arm_ffa: Replace mutex with rwlock to avoid sleep in atomic context The current use of a mutex to protect the notifier hashtable accesses can lead to issues in the atomic context. It results in the below kernel warnings: | BUG: sleeping function called from invalid context at kernel/locking/mutex.c:258 | in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 9, name: kworker/0:0 | preempt_count: 1, expected: 0 | RCU nest depth: 0, expected: 0 | CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.14.0 #4 | Workqueue: ffa_pcpu_irq_notification notif_pcpu_irq_work_fn | Call trace: | show_stack+0x18/0x24 (C) | dump_stack_lvl+0x78/0x90 | dump_stack+0x18/0x24 | __might_resched+0x114/0x170 | __might_sleep+0x48/0x98 | mutex_lock+0x24/0x80 | handle_notif_callbacks+0x54/0xe0 | notif_get_and_handle+0x40/0x88 | generic_exec_single+0x80/0xc0 | smp_call_function_single+0xfc/0x1a0 | notif_pcpu_irq_work_fn+0x2c/0x38 | process_one_work+0x14c/0x2b4 | worker_thread+0x2e4/0x3e0 | kthread+0x13c/0x210 | ret_from_fork+0x10/0x20 To address this, replace the mutex with an rwlock to protect the notifier hashtable accesses. This ensures that read-side locking does not sleep and multiple readers can acquire the lock concurrently, avoiding unnecessary contention and potential deadlocks. Writer access remains exclusive, preserving correctness. This change resolves warnings from lockdep about potential sleep in atomic context.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Prevent deadlock while disabling aRFS When disabling aRFS under the `priv->state_lock`, any scheduled aRFS works are canceled using the `cancel_work_sync` function, which waits for the work to end if it has already started. However, while waiting for the work handler, the handler will try to acquire the `state_lock` which is already acquired. The worker acquires the lock to delete the rules if the state is down, which is not the worker's responsibility since disabling aRFS deletes the rules. Add an aRFS state variable, which indicates whether the aRFS is enabled and prevent adding rules when the aRFS is disabled. Kernel log: ====================================================== WARNING: possible circular locking dependency detected 6.7.0-rc4_net_next_mlx5_5483eb2 #1 Tainted: G I ------------------------------------------------------ ethtool/386089 is trying to acquire lock: ffff88810f21ce68 ((work_completion)(&rule->arfs_work)){+.+.}-{0:0}, at: __flush_work+0x74/0x4e0 but task is already holding lock: ffff8884a1808cc0 (&priv->state_lock){+.+.}-{3:3}, at: mlx5e_ethtool_set_channels+0x53/0x200 [mlx5_core] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&priv->state_lock){+.+.}-{3:3}: __mutex_lock+0x80/0xc90 arfs_handle_work+0x4b/0x3b0 [mlx5_core] process_one_work+0x1dc/0x4a0 worker_thread+0x1bf/0x3c0 kthread+0xd7/0x100 ret_from_fork+0x2d/0x50 ret_from_fork_asm+0x11/0x20 -> #0 ((work_completion)(&rule->arfs_work)){+.+.}-{0:0}: __lock_acquire+0x17b4/0x2c80 lock_acquire+0xd0/0x2b0 __flush_work+0x7a/0x4e0 __cancel_work_timer+0x131/0x1c0 arfs_del_rules+0x143/0x1e0 [mlx5_core] mlx5e_arfs_disable+0x1b/0x30 [mlx5_core] mlx5e_ethtool_set_channels+0xcb/0x200 [mlx5_core] ethnl_set_channels+0x28f/0x3b0 ethnl_default_set_doit+0xec/0x240 genl_family_rcv_msg_doit+0xd0/0x120 genl_rcv_msg+0x188/0x2c0 netlink_rcv_skb+0x54/0x100 genl_rcv+0x24/0x40 netlink_unicast+0x1a1/0x270 netlink_sendmsg+0x214/0x460 __sock_sendmsg+0x38/0x60 __sys_sendto+0x113/0x170 __x64_sys_sendto+0x20/0x30 do_syscall_64+0x40/0xe0 entry_SYSCALL_64_after_hwframe+0x46/0x4e other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&priv->state_lock); lock((work_completion)(&rule->arfs_work)); lock(&priv->state_lock); lock((work_completion)(&rule->arfs_work)); *** DEADLOCK *** 3 locks held by ethtool/386089: #0: ffffffff82ea7210 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 #1: ffffffff82e94c88 (rtnl_mutex){+.+.}-{3:3}, at: ethnl_default_set_doit+0xd3/0x240 #2: ffff8884a1808cc0 (&priv->state_lock){+.+.}-{3:3}, at: mlx5e_ethtool_set_channels+0x53/0x200 [mlx5_core] stack backtrace: CPU: 15 PID: 386089 Comm: ethtool Tainted: G I 6.7.0-rc4_net_next_mlx5_5483eb2 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x60/0xa0 check_noncircular+0x144/0x160 __lock_acquire+0x17b4/0x2c80 lock_acquire+0xd0/0x2b0 ? __flush_work+0x74/0x4e0 ? save_trace+0x3e/0x360 ? __flush_work+0x74/0x4e0 __flush_work+0x7a/0x4e0 ? __flush_work+0x74/0x4e0 ? __lock_acquire+0xa78/0x2c80 ? lock_acquire+0xd0/0x2b0 ? mark_held_locks+0x49/0x70 __cancel_work_timer+0x131/0x1c0 ? mark_held_locks+0x49/0x70 arfs_del_rules+0x143/0x1e0 [mlx5_core] mlx5e_arfs_disable+0x1b/0x30 [mlx5_core] mlx5e_ethtool_set_channels+0xcb/0x200 [mlx5_core] ethnl_set_channels+0x28f/0x3b0 ethnl_default_set_doit+0xec/0x240 genl_family_rcv_msg_doit+0xd0/0x120 genl_rcv_msg+0x188/0x2c0 ? ethn ---truncated---

btrfs in the Linux kernel before 5.13.4 allows attackers to cause a denial of service (deadlock) via processes that trigger allocation of new system chunks during times when there is a shortage of free space in the system space_info.

In the Linux kernel, the following vulnerability has been resolved: PCI: pciehp: Avoid unnecessary device replacement check Hot-removal of nested PCI hotplug ports suffers from a long-standing race condition which can lead to a deadlock: A parent hotplug port acquires pci_lock_rescan_remove(), then waits for pciehp to unbind from a child hotplug port. Meanwhile that child hotplug port tries to acquire pci_lock_rescan_remove() as well in order to remove its own children. The deadlock only occurs if the parent acquires pci_lock_rescan_remove() first, not if the child happens to acquire it first. Several workarounds to avoid the issue have been proposed and discarded over the years, e.g.: https://lore.kernel.org/r/4c882e25194ba8282b78fe963fec8faae7cf23eb.1529173804.git.lukas@wunner.de/ A proper fix is being worked on, but needs more time as it is nontrivial and necessarily intrusive. Recent commit 9d573d19547b ("PCI: pciehp: Detect device replacement during system sleep") provokes more frequent occurrence of the deadlock when removing more than one Thunderbolt device during system sleep. The commit sought to detect device replacement, but also triggered on device removal. Differentiating reliably between replacement and removal is impossible because pci_get_dsn() returns 0 both if the device was removed, as well as if it was replaced with one lacking a Device Serial Number. Avoid the more frequent occurrence of the deadlock by checking whether the hotplug port itself was hot-removed. If so, there's no sense in checking whether its child device was replaced. This works because the ->resume_noirq() callback is invoked in top-down order for the entire hierarchy: A parent hotplug port detecting device replacement (or removal) marks all children as removed using pci_dev_set_disconnected() and a child hotplug port can then reliably detect being removed.

In the Linux kernel, the following vulnerability has been resolved: serial: imx: Introduce timeout when waiting on transmitter empty By waiting at most 1 second for USR2_TXDC to be set, we avoid a potential deadlock. In case of the timeout, there is not much we can do, so we simply ignore the transmitter state and optimistically try to continue.

In the Linux kernel, the following vulnerability has been resolved: PCI: Avoid pci_dev_lock() AB/BA deadlock with sriov_numvfs_store() The sysfs sriov_numvfs_store() path acquires the device lock before the config space access lock: sriov_numvfs_store device_lock # A (1) acquire device lock sriov_configure vfio_pci_sriov_configure # (for example) vfio_pci_core_sriov_configure pci_disable_sriov sriov_disable pci_cfg_access_lock pci_wait_cfg # B (4) wait for dev->block_cfg_access == 0 Previously, pci_dev_lock() acquired the config space access lock before the device lock: pci_dev_lock pci_cfg_access_lock dev->block_cfg_access = 1 # B (2) set dev->block_cfg_access = 1 device_lock # A (3) wait for device lock Any path that uses pci_dev_lock(), e.g., pci_reset_function(), may deadlock with sriov_numvfs_store() if the operations occur in the sequence (1) (2) (3) (4). Avoid the deadlock by reversing the order in pci_dev_lock() so it acquires the device lock before the config space access lock, the same as the sriov_numvfs_store() path. [bhelgaas: combined and adapted commit log from Jay Zhou's independent subsequent posting: https://lore.kernel.org/r/20220404062539.1710-1-jianjay.zhou@huawei.com]

In the Linux kernel, the following vulnerability has been resolved: bcache: avoid journal no-space deadlock by reserving 1 journal bucket The journal no-space deadlock was reported time to time. Such deadlock can happen in the following situation. When all journal buckets are fully filled by active jset with heavy write I/O load, the cache set registration (after a reboot) will load all active jsets and inserting them into the btree again (which is called journal replay). If a journaled bkey is inserted into a btree node and results btree node split, new journal request might be triggered. For example, the btree grows one more level after the node split, then the root node record in cache device super block will be upgrade by bch_journal_meta() from bch_btree_set_root(). But there is no space in journal buckets, the journal replay has to wait for new journal bucket to be reclaimed after at least one journal bucket replayed. This is one example that how the journal no-space deadlock happens. The solution to avoid the deadlock is to reserve 1 journal bucket in run time, and only permit the reserved journal bucket to be used during cache set registration procedure for things like journal replay. Then the journal space will never be fully filled, there is no chance for journal no-space deadlock to happen anymore. This patch adds a new member "bool do_reserve" in struct journal, it is inititalized to 0 (false) when struct journal is allocated, and set to 1 (true) by bch_journal_space_reserve() when all initialization done in run_cache_set(). In the run time when journal_reclaim() tries to allocate a new journal bucket, free_journal_buckets() is called to check whether there are enough free journal buckets to use. If there is only 1 free journal bucket and journal->do_reserve is 1 (true), the last bucket is reserved and free_journal_buckets() will return 0 to indicate no free journal bucket. Then journal_reclaim() will give up, and try next time to see whetheer there is free journal bucket to allocate. By this method, there is always 1 jouranl bucket reserved in run time. During the cache set registration, journal->do_reserve is 0 (false), so the reserved journal bucket can be used to avoid the no-space deadlock.

In the Linux kernel, the following vulnerability has been resolved: drivers: staging: rtl8192e: Fix deadlock in rtllib_beacons_stop() There is a deadlock in rtllib_beacons_stop(), which is shown below: (Thread 1) | (Thread 2) | rtllib_send_beacon() rtllib_beacons_stop() | mod_timer() spin_lock_irqsave() //(1) | (wait a time) ... | rtllib_send_beacon_cb() del_timer_sync() | spin_lock_irqsave() //(2) (wait timer to stop) | ... We hold ieee->beacon_lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need ieee->beacon_lock in position (2) of thread 2. As a result, rtllib_beacons_stop() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_irqsave(), which could let timer handler to obtain the needed lock.

In the Linux kernel, the following vulnerability has been resolved: VMCI: Use threaded irqs instead of tasklets The vmci_dispatch_dgs() tasklet function calls vmci_read_data() which uses wait_event() resulting in invalid sleep in an atomic context (and therefore potentially in a deadlock). Use threaded irqs to fix this issue and completely remove usage of tasklets. [ 20.264639] BUG: sleeping function called from invalid context at drivers/misc/vmw_vmci/vmci_guest.c:145 [ 20.264643] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 762, name: vmtoolsd [ 20.264645] preempt_count: 101, expected: 0 [ 20.264646] RCU nest depth: 0, expected: 0 [ 20.264647] 1 lock held by vmtoolsd/762: [ 20.264648] #0: ffff0000874ae440 (sk_lock-AF_VSOCK){+.+.}-{0:0}, at: vsock_connect+0x60/0x330 [vsock] [ 20.264658] Preemption disabled at: [ 20.264659] [<ffff80000151d7d8>] vmci_send_datagram+0x44/0xa0 [vmw_vmci] [ 20.264665] CPU: 0 PID: 762 Comm: vmtoolsd Not tainted 5.19.0-0.rc8.20220727git39c3c396f813.60.fc37.aarch64 #1 [ 20.264667] Hardware name: VMware, Inc. VBSA/VBSA, BIOS VEFI 12/31/2020 [ 20.264668] Call trace: [ 20.264669] dump_backtrace+0xc4/0x130 [ 20.264672] show_stack+0x24/0x80 [ 20.264673] dump_stack_lvl+0x88/0xb4 [ 20.264676] dump_stack+0x18/0x34 [ 20.264677] __might_resched+0x1a0/0x280 [ 20.264679] __might_sleep+0x58/0x90 [ 20.264681] vmci_read_data+0x74/0x120 [vmw_vmci] [ 20.264683] vmci_dispatch_dgs+0x64/0x204 [vmw_vmci] [ 20.264686] tasklet_action_common.constprop.0+0x13c/0x150 [ 20.264688] tasklet_action+0x40/0x50 [ 20.264689] __do_softirq+0x23c/0x6b4 [ 20.264690] __irq_exit_rcu+0x104/0x214 [ 20.264691] irq_exit_rcu+0x1c/0x50 [ 20.264693] el1_interrupt+0x38/0x6c [ 20.264695] el1h_64_irq_handler+0x18/0x24 [ 20.264696] el1h_64_irq+0x68/0x6c [ 20.264697] preempt_count_sub+0xa4/0xe0 [ 20.264698] _raw_spin_unlock_irqrestore+0x64/0xb0 [ 20.264701] vmci_send_datagram+0x7c/0xa0 [vmw_vmci] [ 20.264703] vmci_datagram_dispatch+0x84/0x100 [vmw_vmci] [ 20.264706] vmci_datagram_send+0x2c/0x40 [vmw_vmci] [ 20.264709] vmci_transport_send_control_pkt+0xb8/0x120 [vmw_vsock_vmci_transport] [ 20.264711] vmci_transport_connect+0x40/0x7c [vmw_vsock_vmci_transport] [ 20.264713] vsock_connect+0x278/0x330 [vsock] [ 20.264715] __sys_connect_file+0x8c/0xc0 [ 20.264718] __sys_connect+0x84/0xb4 [ 20.264720] __arm64_sys_connect+0x2c/0x3c [ 20.264721] invoke_syscall+0x78/0x100 [ 20.264723] el0_svc_common.constprop.0+0x68/0x124 [ 20.264724] do_el0_svc+0x38/0x4c [ 20.264725] el0_svc+0x60/0x180 [ 20.264726] el0t_64_sync_handler+0x11c/0x150 [ 20.264728] el0t_64_sync+0x190/0x194

In the Linux kernel, the following vulnerability has been resolved: tty: fix deadlock caused by calling printk() under tty_port->lock pty_write() invokes kmalloc() which may invoke a normal printk() to print failure message. This can cause a deadlock in the scenario reported by syz-bot below: CPU0 CPU1 CPU2 ---- ---- ---- lock(console_owner); lock(&port_lock_key); lock(&port->lock); lock(&port_lock_key); lock(&port->lock); lock(console_owner); As commit dbdda842fe96 ("printk: Add console owner and waiter logic to load balance console writes") said, such deadlock can be prevented by using printk_deferred() in kmalloc() (which is invoked in the section guarded by the port->lock). But there are too many printk() on the kmalloc() path, and kmalloc() can be called from anywhere, so changing printk() to printk_deferred() is too complicated and inelegant. Therefore, this patch chooses to specify __GFP_NOWARN to kmalloc(), so that printk() will not be called, and this deadlock problem can be avoided. Syzbot reported the following lockdep error: ====================================================== WARNING: possible circular locking dependency detected 5.4.143-00237-g08ccc19a-dirty #10 Not tainted ------------------------------------------------------ syz-executor.4/29420 is trying to acquire lock: ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1752 [inline] ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x2ca/0x470 kernel/printk/printk.c:2023 but task is already holding lock: ffff8880119c9158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xf4/0x1f0 drivers/tty/pty.c:120 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&port->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 tty_port_tty_get drivers/tty/tty_port.c:288 [inline] <-- lock(&port->lock); tty_port_default_wakeup+0x1d/0xb0 drivers/tty/tty_port.c:47 serial8250_tx_chars+0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767 serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] <-- lock(&port_lock_key); serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870 serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x109/0xa50 kernel/irq/handle.c:156 [...] -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 serial8250_console_write+0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198 <-- lock(&port_lock_key); call_console_drivers kernel/printk/printk.c:1819 [inline] console_unlock+0x8cb/0xd00 kernel/printk/printk.c:2504 vprintk_emit+0x1b5/0x470 kernel/printk/printk.c:2024 <-- lock(console_owner); vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394 printk+0xba/0xed kernel/printk/printk.c:2084 register_console+0x8b3/0xc10 kernel/printk/printk.c:2829 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681 console_init+0x49d/0x6d3 kernel/printk/printk.c:2915 start_kernel+0x5e9/0x879 init/main.c:713 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 -> #0 (console_owner){....}-{0:0}: [...] lock_acquire+0x127/0x340 kernel/locking/lockdep.c:4734 console_trylock_spinning kernel/printk/printk.c:1773 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: dm: dm-crypt: Do not partially accept write BIOs with zoned targets Read and write operations issued to a dm-crypt target may be split according to the dm-crypt internal limits defined by the max_read_size and max_write_size module parameters (default is 128 KB). The intent is to improve processing time of large BIOs by splitting them into smaller operations that can be parallelized on different CPUs. For zoned dm-crypt targets, this BIO splitting is still done but without the parallel execution to ensure that the issuing order of write operations to the underlying devices remains sequential. However, the splitting itself causes other problems: 1) Since dm-crypt relies on the block layer zone write plugging to handle zone append emulation using regular write operations, the reminder of a split write BIO will always be plugged into the target zone write plugged. Once the on-going write BIO finishes, this reminder BIO is unplugged and issued from the zone write plug work. If this reminder BIO itself needs to be split, the reminder will be re-issued and plugged again, but that causes a call to a blk_queue_enter(), which may block if a queue freeze operation was initiated. This results in a deadlock as DM submission still holds BIOs that the queue freeze side is waiting for. 2) dm-crypt relies on the emulation done by the block layer using regular write operations for processing zone append operations. This still requires to properly return the written sector as the BIO sector of the original BIO. However, this can be done correctly only and only if there is a single clone BIO used for processing the original zone append operation issued by the user. If the size of a zone append operation is larger than dm-crypt max_write_size, then the orginal BIO will be split and processed as a chain of regular write operations. Such chaining result in an incorrect written sector being returned to the zone append issuer using the original BIO sector. This in turn results in file system data corruptions using xfs or btrfs. Fix this by modifying get_max_request_size() to always return the size of the BIO to avoid it being split with dm_accpet_partial_bio() in crypt_map(). get_max_request_size() is renamed to get_max_request_sectors() to clarify the unit of the value returned and its interface is changed to take a struct dm_target pointer and a pointer to the struct bio being processed. In addition to this change, to ensure that crypt_alloc_buffer() works correctly, set the dm-crypt device max_hw_sectors limit to be at most BIO_MAX_VECS << PAGE_SECTORS_SHIFT (1 MB with a 4KB page architecture). This forces DM core to split write BIOs before passing them to crypt_map(), and thus guaranteeing that dm-crypt can always accept an entire write BIO without needing to split it. This change does not have any effect on the read path of dm-crypt. Read operations can still be split and the BIO fragments processed in parallel. There is also no impact on the performance of the write path given that all zone write BIOs were already processed inline instead of in parallel. This change also does not affect in any way regular dm-crypt block devices.

In the Linux kernel, the following vulnerability has been resolved: drivers: usb: host: Fix deadlock in oxu_bus_suspend() There is a deadlock in oxu_bus_suspend(), which is shown below: (Thread 1) | (Thread 2) | timer_action() oxu_bus_suspend() | mod_timer() spin_lock_irq() //(1) | (wait a time) ... | oxu_watchdog() del_timer_sync() | spin_lock_irq() //(2) (wait timer to stop) | ... We hold oxu->lock in position (1) of thread 1, and use del_timer_sync() to wait timer to stop, but timer handler also need oxu->lock in position (2) of thread 2. As a result, oxu_bus_suspend() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_irq(), which could let timer handler to obtain the needed lock.

In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Move cfg_log_verbose check before calling lpfc_dmp_dbg() In an attempt to log message 0126 with LOG_TRACE_EVENT, the following hard lockup call trace hangs the system. Call Trace: _raw_spin_lock_irqsave+0x32/0x40 lpfc_dmp_dbg.part.32+0x28/0x220 [lpfc] lpfc_cmpl_els_fdisc+0x145/0x460 [lpfc] lpfc_sli_cancel_jobs+0x92/0xd0 [lpfc] lpfc_els_flush_cmd+0x43c/0x670 [lpfc] lpfc_els_flush_all_cmd+0x37/0x60 [lpfc] lpfc_sli4_async_event_proc+0x956/0x1720 [lpfc] lpfc_do_work+0x1485/0x1d70 [lpfc] kthread+0x112/0x130 ret_from_fork+0x1f/0x40 Kernel panic - not syncing: Hard LOCKUP The same CPU tries to claim the phba->port_list_lock twice. Move the cfg_log_verbose checks as part of the lpfc_printf_vlog() and lpfc_printf_log() macros before calling lpfc_dmp_dbg(). There is no need to take the phba->port_list_lock within lpfc_dmp_dbg().

In the Linux kernel, the following vulnerability has been resolved: media: mediatek: vcodec: prevent kernel crash when rmmod mtk-vcodec-dec.ko If the driver support subdev mode, the parameter "dev->pm.dev" will be NULL in mtk_vcodec_dec_remove. Kernel will crash when try to rmmod mtk-vcodec-dec.ko. [ 4380.702726] pc : do_raw_spin_trylock+0x4/0x80 [ 4380.707075] lr : _raw_spin_lock_irq+0x90/0x14c [ 4380.711509] sp : ffff80000819bc10 [ 4380.714811] x29: ffff80000819bc10 x28: ffff3600c03e4000 x27: 0000000000000000 [ 4380.721934] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [ 4380.729057] x23: ffff3600c0f34930 x22: ffffd5e923549000 x21: 0000000000000220 [ 4380.736179] x20: 0000000000000208 x19: ffffd5e9213e8ebc x18: 0000000000000020 [ 4380.743298] x17: 0000002000000000 x16: ffffd5e9213e8e90 x15: 696c346f65646976 [ 4380.750420] x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000040 [ 4380.757542] x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 [ 4380.764664] x8 : 0000000000000000 x7 : ffff3600c7273ae8 x6 : ffffd5e9213e8ebc [ 4380.771786] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000 [ 4380.778908] x2 : 0000000000000000 x1 : ffff3600c03e4000 x0 : 0000000000000208 [ 4380.786031] Call trace: [ 4380.788465] do_raw_spin_trylock+0x4/0x80 [ 4380.792462] __pm_runtime_disable+0x2c/0x1b0 [ 4380.796723] mtk_vcodec_dec_remove+0x5c/0xa0 [mtk_vcodec_dec] [ 4380.802466] platform_remove+0x2c/0x60 [ 4380.806204] __device_release_driver+0x194/0x250 [ 4380.810810] driver_detach+0xc8/0x15c [ 4380.814462] bus_remove_driver+0x5c/0xb0 [ 4380.818375] driver_unregister+0x34/0x64 [ 4380.822288] platform_driver_unregister+0x18/0x24 [ 4380.826979] mtk_vcodec_dec_driver_exit+0x1c/0x888 [mtk_vcodec_dec] [ 4380.833240] __arm64_sys_delete_module+0x190/0x224 [ 4380.838020] invoke_syscall+0x48/0x114 [ 4380.841760] el0_svc_common.constprop.0+0x60/0x11c [ 4380.846540] do_el0_svc+0x28/0x90 [ 4380.849844] el0_svc+0x4c/0x100 [ 4380.852975] el0t_64_sync_handler+0xec/0xf0 [ 4380.857148] el0t_64_sync+0x190/0x194 [ 4380.860801] Code: 94431515 17ffffca d503201f d503245f (b9400004)

In the Linux kernel, the following vulnerability has been resolved: driver core: Fix wait_for_device_probe() & deferred_probe_timeout interaction Mounting NFS rootfs was timing out when deferred_probe_timeout was non-zero [1]. This was because ip_auto_config() initcall times out waiting for the network interfaces to show up when deferred_probe_timeout was non-zero. While ip_auto_config() calls wait_for_device_probe() to make sure any currently running deferred probe work or asynchronous probe finishes, that wasn't sufficient to account for devices being deferred until deferred_probe_timeout. Commit 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") tried to fix that by making sure wait_for_device_probe() waits for deferred_probe_timeout to expire before returning. However, if wait_for_device_probe() is called from the kernel_init() context: - Before deferred_probe_initcall() [2], it causes the boot process to hang due to a deadlock. - After deferred_probe_initcall() [3], it blocks kernel_init() from continuing till deferred_probe_timeout expires and beats the point of deferred_probe_timeout that's trying to wait for userspace to load modules. Neither of this is good. So revert the changes to wait_for_device_probe(). [1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01MB4544.jpnprd01.prod.outlook.com/ [2] - https://lore.kernel.org/lkml/YowHNo4sBjr9ijZr@dev-arch.thelio-3990X/ [3] - https://lore.kernel.org/lkml/Yo3WvGnNk3LvLb7R@linutronix.de/

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix sleeping function called from invalid context on RT kernel When setting bootparams="trace_event=initcall:initcall_start tp_printk=1" in the cmdline, the output_printk() was called, and the spin_lock_irqsave() was called in the atomic and irq disable interrupt context suitation. On the PREEMPT_RT kernel, these locks are replaced with sleepable rt-spinlock, so the stack calltrace will be triggered. Fix it by raw_spin_lock_irqsave when PREEMPT_RT and "trace_event=initcall:initcall_start tp_printk=1" enabled. BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 2, expected: 0 RCU nest depth: 0, expected: 0 Preemption disabled at: [<ffffffff8992303e>] try_to_wake_up+0x7e/0xba0 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.1-rt17+ #19 34c5812404187a875f32bee7977f7367f9679ea7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x60/0x8c dump_stack+0x10/0x12 __might_resched.cold+0x11d/0x155 rt_spin_lock+0x40/0x70 trace_event_buffer_commit+0x2fa/0x4c0 ? map_vsyscall+0x93/0x93 trace_event_raw_event_initcall_start+0xbe/0x110 ? perf_trace_initcall_finish+0x210/0x210 ? probe_sched_wakeup+0x34/0x40 ? ttwu_do_wakeup+0xda/0x310 ? trace_hardirqs_on+0x35/0x170 ? map_vsyscall+0x93/0x93 do_one_initcall+0x217/0x3c0 ? trace_event_raw_event_initcall_level+0x170/0x170 ? push_cpu_stop+0x400/0x400 ? cblist_init_generic+0x241/0x290 kernel_init_freeable+0x1ac/0x347 ? _raw_spin_unlock_irq+0x65/0x80 ? rest_init+0xf0/0xf0 kernel_init+0x1e/0x150 ret_from_fork+0x22/0x30 </TASK>

In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: traverse devices under chunk_mutex in btrfs_can_activate_zone btrfs_can_activate_zone() can be called with the device_list_mutex already held, which will lead to a deadlock: insert_dev_extents() // Takes device_list_mutex `-> insert_dev_extent() `-> btrfs_insert_empty_item() `-> btrfs_insert_empty_items() `-> btrfs_search_slot() `-> btrfs_cow_block() `-> __btrfs_cow_block() `-> btrfs_alloc_tree_block() `-> btrfs_reserve_extent() `-> find_free_extent() `-> find_free_extent_update_loop() `-> can_allocate_chunk() `-> btrfs_can_activate_zone() // Takes device_list_mutex again Instead of using the RCU on fs_devices->device_list we can use fs_devices->alloc_list, protected by the chunk_mutex to traverse the list of active devices. We are in the chunk allocation thread. The newer chunk allocation happens from the devices in the fs_device->alloc_list protected by the chunk_mutex. btrfs_create_chunk() lockdep_assert_held(&info->chunk_mutex); gather_device_info list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) Also, a device that reappears after the mount won't join the alloc_list yet and, it will be in the dev_list, which we don't want to consider in the context of the chunk alloc. [15.166572] WARNING: possible recursive locking detected [15.167117] 5.17.0-rc6-dennis #79 Not tainted [15.167487] -------------------------------------------- [15.167733] kworker/u8:3/146 is trying to acquire lock: [15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: find_free_extent+0x15a/0x14f0 [btrfs] [15.167733] [15.167733] but task is already holding lock: [15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs] [15.167733] [15.167733] other info that might help us debug this: [15.167733] Possible unsafe locking scenario: [15.167733] [15.171834] CPU0 [15.171834] ---- [15.171834] lock(&fs_devs->device_list_mutex); [15.171834] lock(&fs_devs->device_list_mutex); [15.171834] [15.171834] *** DEADLOCK *** [15.171834] [15.171834] May be due to missing lock nesting notation [15.171834] [15.171834] 5 locks held by kworker/u8:3/146: [15.171834] #0: ffff888100050938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0 [15.171834] #1: ffffc9000067be80 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0 [15.176244] #2: ffff88810521e620 (sb_internal){.+.+}-{0:0}, at: flush_space+0x335/0x600 [btrfs] [15.176244] #3: ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs] [15.176244] #4: ffff8881152e4b78 (btrfs-dev-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x130 [btrfs] [15.179641] [15.179641] stack backtrace: [15.179641] CPU: 1 PID: 146 Comm: kworker/u8:3 Not tainted 5.17.0-rc6-dennis #79 [15.179641] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014 [15.179641] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] [15.179641] Call Trace: [15.179641] <TASK> [15.179641] dump_stack_lvl+0x45/0x59 [15.179641] __lock_acquire.cold+0x217/0x2b2 [15.179641] lock_acquire+0xbf/0x2b0 [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] __mutex_lock+0x8e/0x970 [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] ? lock_is_held_type+0xd7/0x130 [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] ? _raw_spin_unlock+0x24/0x40 [15.183838] ? btrfs_get_alloc_profile+0x106/0x230 [btrfs] [15.187601] btrfs_reserve_extent+0x131/0x260 [btrfs] [15. ---truncated---

In the Linux kernel, the following vulnerability has been resolved: net, neigh: Do not trigger immediate probes on NUD_FAILED from neigh_managed_work syzkaller was able to trigger a deadlock for NTF_MANAGED entries [0]: kworker/0:16/14617 is trying to acquire lock: ffffffff8d4dd370 (&tbl->lock){++-.}-{2:2}, at: ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652 [...] but task is already holding lock: ffffffff8d4dd370 (&tbl->lock){++-.}-{2:2}, at: neigh_managed_work+0x35/0x250 net/core/neighbour.c:1572 The neighbor entry turned to NUD_FAILED state, where __neigh_event_send() triggered an immediate probe as per commit cd28ca0a3dd1 ("neigh: reduce arp latency") via neigh_probe() given table lock was held. One option to fix this situation is to defer the neigh_probe() back to the neigh_timer_handler() similarly as pre cd28ca0a3dd1. For the case of NTF_MANAGED, this deferral is acceptable given this only happens on actual failure state and regular / expected state is NUD_VALID with the entry already present. The fix adds a parameter to __neigh_event_send() in order to communicate whether immediate probe is allowed or disallowed. Existing call-sites of neigh_event_send() default as-is to immediate probe. However, the neigh_managed_work() disables it via use of neigh_event_send_probe(). [0] <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2956 [inline] check_deadlock kernel/locking/lockdep.c:2999 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:334 ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652 ip6_finish_output2+0x1070/0x14f0 net/ipv6/ip6_output.c:123 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508 ndisc_send_ns+0x3a9/0x840 net/ipv6/ndisc.c:650 ndisc_solicit+0x2cd/0x4f0 net/ipv6/ndisc.c:742 neigh_probe+0xc2/0x110 net/core/neighbour.c:1040 __neigh_event_send+0x37d/0x1570 net/core/neighbour.c:1201 neigh_event_send include/net/neighbour.h:470 [inline] neigh_managed_work+0x162/0x250 net/core/neighbour.c:1574 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK>

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Don't call mmput from MMU notifier callback If the process is exiting, the mmput inside mmu notifier callback from compactd or fork or numa balancing could release the last reference of mm struct to call exit_mmap and free_pgtable, this triggers deadlock with below backtrace. The deadlock will leak kfd process as mmu notifier release is not called and cause VRAM leaking. The fix is to take mm reference mmget_non_zero when adding prange to the deferred list to pair with mmput in deferred list work. If prange split and add into pchild list, the pchild work_item.mm is not used, so remove the mm parameter from svm_range_unmap_split and svm_range_add_child. The backtrace of hung task: INFO: task python:348105 blocked for more than 64512 seconds. Call Trace: __schedule+0x1c3/0x550 schedule+0x46/0xb0 rwsem_down_write_slowpath+0x24b/0x4c0 unlink_anon_vmas+0xb1/0x1c0 free_pgtables+0xa9/0x130 exit_mmap+0xbc/0x1a0 mmput+0x5a/0x140 svm_range_cpu_invalidate_pagetables+0x2b/0x40 [amdgpu] mn_itree_invalidate+0x72/0xc0 __mmu_notifier_invalidate_range_start+0x48/0x60 try_to_unmap_one+0x10fa/0x1400 rmap_walk_anon+0x196/0x460 try_to_unmap+0xbb/0x210 migrate_page_unmap+0x54d/0x7e0 migrate_pages_batch+0x1c3/0xae0 migrate_pages_sync+0x98/0x240 migrate_pages+0x25c/0x520 compact_zone+0x29d/0x590 compact_zone_order+0xb6/0xf0 try_to_compact_pages+0xbe/0x220 __alloc_pages_direct_compact+0x96/0x1a0 __alloc_pages_slowpath+0x410/0x930 __alloc_pages_nodemask+0x3a9/0x3e0 do_huge_pmd_anonymous_page+0xd7/0x3e0 __handle_mm_fault+0x5e3/0x5f0 handle_mm_fault+0xf7/0x2e0 hmm_vma_fault.isra.0+0x4d/0xa0 walk_pmd_range.isra.0+0xa8/0x310 walk_pud_range+0x167/0x240 walk_pgd_range+0x55/0x100 __walk_page_range+0x87/0x90 walk_page_range+0xf6/0x160 hmm_range_fault+0x4f/0x90 amdgpu_hmm_range_get_pages+0x123/0x230 [amdgpu] amdgpu_ttm_tt_get_user_pages+0xb1/0x150 [amdgpu] init_user_pages+0xb1/0x2a0 [amdgpu] amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu+0x543/0x7d0 [amdgpu] kfd_ioctl_alloc_memory_of_gpu+0x24c/0x4e0 [amdgpu] kfd_ioctl+0x29d/0x500 [amdgpu] (cherry picked from commit a29e067bd38946f752b0ef855f3dfff87e77bec7)

The handle_stop_signal function in signal.c in Linux kernel 2.6.11 up to other versions before 2.6.13 and 2.6.12.6 allows local users to cause a denial of service (deadlock) by sending a SIGKILL to a real-time threaded process while it is performing a core dump.