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: 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: 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: 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: 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: 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: 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: usb: cdns3: Fix deadlock when using NCM gadget The cdns3 driver has the same NCM deadlock as fixed in cdnsp by commit 58f2fcb3a845 ("usb: cdnsp: Fix deadlock issue during using NCM gadget"). Under PREEMPT_RT the deadlock can be readily triggered by heavy network traffic, for example using "iperf --bidir" over NCM ethernet link. The deadlock occurs because the threaded interrupt handler gets preempted by a softirq, but both are protected by the same spinlock. Prevent deadlock by disabling softirq during threaded irq handler.

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: 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: iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_fifo Prevent st_lsm6dsx_read_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: 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: 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: 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: 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: dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata Following concurrent processes: P1(drop cache) P2(kworker) drop_caches_sysctl_handler drop_slab shrink_slab down_read(&shrinker_rwsem) - LOCK A do_shrink_slab super_cache_scan prune_icache_sb dispose_list evict ext4_evict_inode ext4_clear_inode ext4_discard_preallocations ext4_mb_load_buddy_gfp ext4_mb_init_cache ext4_read_block_bitmap_nowait ext4_read_bh_nowait submit_bh dm_submit_bio do_worker process_deferred_bios commit metadata_operation_failed dm_pool_abort_metadata down_write(&pmd->root_lock) - LOCK B __destroy_persistent_data_objects dm_block_manager_destroy dm_bufio_client_destroy unregister_shrinker down_write(&shrinker_rwsem) thin_map | dm_thin_find_block ↓ down_read(&pmd->root_lock) --> ABBA deadlock , which triggers hung task: [ 76.974820] INFO: task kworker/u4:3:63 blocked for more than 15 seconds. [ 76.976019] Not tainted 6.1.0-rc4-00011-g8f17dd350364-dirty #910 [ 76.978521] task:kworker/u4:3 state:D stack:0 pid:63 ppid:2 [ 76.978534] Workqueue: dm-thin do_worker [ 76.978552] Call Trace: [ 76.978564] __schedule+0x6ba/0x10f0 [ 76.978582] schedule+0x9d/0x1e0 [ 76.978588] rwsem_down_write_slowpath+0x587/0xdf0 [ 76.978600] down_write+0xec/0x110 [ 76.978607] unregister_shrinker+0x2c/0xf0 [ 76.978616] dm_bufio_client_destroy+0x116/0x3d0 [ 76.978625] dm_block_manager_destroy+0x19/0x40 [ 76.978629] __destroy_persistent_data_objects+0x5e/0x70 [ 76.978636] dm_pool_abort_metadata+0x8e/0x100 [ 76.978643] metadata_operation_failed+0x86/0x110 [ 76.978649] commit+0x6a/0x230 [ 76.978655] do_worker+0xc6e/0xd90 [ 76.978702] process_one_work+0x269/0x630 [ 76.978714] worker_thread+0x266/0x630 [ 76.978730] kthread+0x151/0x1b0 [ 76.978772] INFO: task test.sh:2646 blocked for more than 15 seconds. [ 76.979756] Not tainted 6.1.0-rc4-00011-g8f17dd350364-dirty #910 [ 76.982111] task:test.sh state:D stack:0 pid:2646 ppid:2459 [ 76.982128] Call Trace: [ 76.982139] __schedule+0x6ba/0x10f0 [ 76.982155] schedule+0x9d/0x1e0 [ 76.982159] rwsem_down_read_slowpath+0x4f4/0x910 [ 76.982173] down_read+0x84/0x170 [ 76.982177] dm_thin_find_block+0x4c/0xd0 [ 76.982183] thin_map+0x201/0x3d0 [ 76.982188] __map_bio+0x5b/0x350 [ 76.982195] dm_submit_bio+0x2b6/0x930 [ 76.982202] __submit_bio+0x123/0x2d0 [ 76.982209] submit_bio_noacct_nocheck+0x101/0x3e0 [ 76.982222] submit_bio_noacct+0x389/0x770 [ 76.982227] submit_bio+0x50/0xc0 [ 76.982232] submit_bh_wbc+0x15e/0x230 [ 76.982238] submit_bh+0x14/0x20 [ 76.982241] ext4_read_bh_nowait+0xc5/0x130 [ 76.982247] ext4_read_block_bitmap_nowait+0x340/0xc60 [ 76.982254] ext4_mb_init_cache+0x1ce/0xdc0 [ 76.982259] ext4_mb_load_buddy_gfp+0x987/0xfa0 [ 76.982263] ext4_discard_preallocations+0x45d/0x830 [ 76.982274] ext4_clear_inode+0x48/0xf0 [ 76.982280] ext4_evict_inode+0xcf/0xc70 [ 76.982285] evict+0x119/0x2b0 [ 76.982290] dispose_list+0x43/0xa0 [ 76.982294] prune_icache_sb+0x64/0x90 [ 76.982298] super_cache_scan+0x155/0x210 [ 76.982303] do_shrink_slab+0x19e/0x4e0 [ 76.982310] shrink_slab+0x2bd/0x450 [ 76.982317] drop_slab+0xcc/0x1a0 [ 76.982323] drop_caches_sysctl_handler+0xb7/0xe0 [ 76.982327] proc_sys_call_handler+0x1bc/0x300 [ 76.982331] proc_sys_write+0x17/0x20 [ 76.982334] vfs_write+0x3d3/0x570 [ 76.982342] ksys_write+0x73/0x160 [ 76.982347] __x64_sys_write+0x1e/0x30 [ 76.982352] do_syscall_64+0x35/0x80 [ 76.982357] entry_SYSCALL_64_after_hwframe+0x63/0xcd Funct ---truncated---

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.

Array index overflow in the xfrm_sk_policy_insert function in xfrm_user.c in Linux kernel 2.6 allows local users to cause a denial of service (oops or deadlock) and possibly execute arbitrary code via a p->dir value that is larger than XFRM_POLICY_OUT, which is used as an index in the sock->sk_policy array.

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: net: vlan: don't propagate flags on open With the device instance lock, there is now a possibility of a deadlock: [ 1.211455] ============================================ [ 1.211571] WARNING: possible recursive locking detected [ 1.211687] 6.14.0-rc5-01215-g032756b4ca7a-dirty #5 Not tainted [ 1.211823] -------------------------------------------- [ 1.211936] ip/184 is trying to acquire lock: [ 1.212032] ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_set_allmulti+0x4e/0xb0 [ 1.212207] [ 1.212207] but task is already holding lock: [ 1.212332] ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_open+0x50/0xb0 [ 1.212487] [ 1.212487] other info that might help us debug this: [ 1.212626] Possible unsafe locking scenario: [ 1.212626] [ 1.212751] CPU0 [ 1.212815] ---- [ 1.212871] lock(&dev->lock); [ 1.212944] lock(&dev->lock); [ 1.213016] [ 1.213016] *** DEADLOCK *** [ 1.213016] [ 1.213143] May be due to missing lock nesting notation [ 1.213143] [ 1.213294] 3 locks held by ip/184: [ 1.213371] #0: ffffffff838b53e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock+0x1b/0xa0 [ 1.213543] #1: ffffffff84e5fc70 (&net->rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock+0x37/0xa0 [ 1.213727] #2: ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_open+0x50/0xb0 [ 1.213895] [ 1.213895] stack backtrace: [ 1.213991] CPU: 0 UID: 0 PID: 184 Comm: ip Not tainted 6.14.0-rc5-01215-g032756b4ca7a-dirty #5 [ 1.213993] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 1.213994] Call Trace: [ 1.213995] <TASK> [ 1.213996] dump_stack_lvl+0x8e/0xd0 [ 1.214000] print_deadlock_bug+0x28b/0x2a0 [ 1.214020] lock_acquire+0xea/0x2a0 [ 1.214027] __mutex_lock+0xbf/0xd40 [ 1.214038] dev_set_allmulti+0x4e/0xb0 # real_dev->flags & IFF_ALLMULTI [ 1.214040] vlan_dev_open+0xa5/0x170 # ndo_open on vlandev [ 1.214042] __dev_open+0x145/0x270 [ 1.214046] __dev_change_flags+0xb0/0x1e0 [ 1.214051] netif_change_flags+0x22/0x60 # IFF_UP vlandev [ 1.214053] dev_change_flags+0x61/0xb0 # for each device in group from dev->vlan_info [ 1.214055] vlan_device_event+0x766/0x7c0 # on netdevsim0 [ 1.214058] notifier_call_chain+0x78/0x120 [ 1.214062] netif_open+0x6d/0x90 [ 1.214064] dev_open+0x5b/0xb0 # locks netdevsim0 [ 1.214066] bond_enslave+0x64c/0x1230 [ 1.214075] do_set_master+0x175/0x1e0 # on netdevsim0 [ 1.214077] do_setlink+0x516/0x13b0 [ 1.214094] rtnl_newlink+0xaba/0xb80 [ 1.214132] rtnetlink_rcv_msg+0x440/0x490 [ 1.214144] netlink_rcv_skb+0xeb/0x120 [ 1.214150] netlink_unicast+0x1f9/0x320 [ 1.214153] netlink_sendmsg+0x346/0x3f0 [ 1.214157] __sock_sendmsg+0x86/0xb0 [ 1.214160] ____sys_sendmsg+0x1c8/0x220 [ 1.214164] ___sys_sendmsg+0x28f/0x2d0 [ 1.214179] __x64_sys_sendmsg+0xef/0x140 [ 1.214184] do_syscall_64+0xec/0x1d0 [ 1.214190] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 1.214191] RIP: 0033:0x7f2d1b4a7e56 Device setup: netdevsim0 (down) ^ ^ bond netdevsim1.100@netdevsim1 allmulticast=on (down) When we enslave the lower device (netdevsim0) which has a vlan, we propagate vlan's allmuti/promisc flags during ndo_open. This causes (re)locking on of the real_dev. Propagate allmulti/promisc on flags change, not on the open. There is a slight semantics change that vlans that are down now propagate the flags, but this seems unlikely to result in the real issues. Reproducer: echo 0 1 > /sys/bus/netdevsim/new_device dev_path=$(ls -d /sys/bus/netdevsim/devices/netdevsim0/net/*) dev=$(echo $dev_path | rev | cut -d/ -f1 | rev) ip link set dev $dev name netdevsim0 ip link set dev netdevsim0 up ip link add link netdevsim0 name netdevsim0.100 type vlan id 100 ip link set dev netdevsim0.100 allm ---truncated---

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: ALSA: timer: Don't take register_mutex with copy_from/to_user() The infamous mmap_lock taken in copy_from/to_user() can be often problematic when it's called inside another mutex, as they might lead to deadlocks. In the case of ALSA timer code, the bad pattern is with guard(mutex)(&register_mutex) that covers copy_from/to_user() -- which was mistakenly introduced at converting to guard(), and it had been carefully worked around in the past. This patch fixes those pieces simply by moving copy_from/to_user() out of the register mutex lock again.

In the Linux kernel, the following vulnerability has been resolved: PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type The access to the PCI config space via pci_ops::read and pci_ops::write is a low-level hardware access. The functions can be accessed with disabled interrupts even on PREEMPT_RT. The pci_lock is a raw_spinlock_t for this purpose. A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be acquired with disabled interrupts. The vmd_dev::cfg_lock is accessed in the same context as the pci_lock. Make vmd_dev::cfg_lock a raw_spinlock_t type so it can be used with interrupts disabled. This was reported as: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 Call Trace: rt_spin_lock+0x4e/0x130 vmd_pci_read+0x8d/0x100 [vmd] pci_user_read_config_byte+0x6f/0xe0 pci_read_config+0xfe/0x290 sysfs_kf_bin_read+0x68/0x90 [bigeasy: reword commit message] Tested-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com> [kwilczynski: commit log] [bhelgaas: add back report info from https://lore.kernel.org/lkml/20241218115951.83062-1-ryotkkr98@gmail.com/]

In the Linux kernel, the following vulnerability has been resolved: Revert "arm64: dts: qcom: sdm845: Affirm IDR0.CCTW on apps_smmu" There are reports that the pagetable walker cache coherency is not a given across the spectrum of SDM845/850 devices, leading to lock-ups and resets. It works fine on some devices (like the Dragonboard 845c, but not so much on the Lenovo Yoga C630). This unfortunately looks like a fluke in firmware development, where likely somewhere in the vast hypervisor stack, a change to accommodate for this was only introduced after the initial software release (which often serves as a baseline for products). Revert the change to avoid additional guesswork around crashes. This reverts commit 6b31a9744b8726c69bb0af290f8475a368a4b805.

In the Linux kernel, the following vulnerability has been resolved: gpio: rcar: Use raw_spinlock to protect register access Use raw_spinlock in order to fix spurious messages about invalid context when spinlock debugging is enabled. The lock is only used to serialize register access. [ 4.239592] ============================= [ 4.239595] [ BUG: Invalid wait context ] [ 4.239599] 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35 Not tainted [ 4.239603] ----------------------------- [ 4.239606] kworker/u8:5/76 is trying to lock: [ 4.239609] ffff0000091898a0 (&p->lock){....}-{3:3}, at: gpio_rcar_config_interrupt_input_mode+0x34/0x164 [ 4.239641] other info that might help us debug this: [ 4.239643] context-{5:5} [ 4.239646] 5 locks held by kworker/u8:5/76: [ 4.239651] #0: ffff0000080fb148 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x190/0x62c [ 4.250180] OF: /soc/sound@ec500000/ports/port@0/endpoint: Read of boolean property 'frame-master' with a value. [ 4.254094] #1: ffff80008299bd80 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1b8/0x62c [ 4.254109] #2: ffff00000920c8f8 [ 4.258345] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'bitclock-master' with a value. [ 4.264803] (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0x3c/0xdc [ 4.264820] #3: ffff00000a50ca40 (request_class#2){+.+.}-{4:4}, at: __setup_irq+0xa0/0x690 [ 4.264840] #4: [ 4.268872] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'frame-master' with a value. [ 4.273275] ffff00000a50c8c8 (lock_class){....}-{2:2}, at: __setup_irq+0xc4/0x690 [ 4.296130] renesas_sdhi_internal_dmac ee100000.mmc: mmc1 base at 0x00000000ee100000, max clock rate 200 MHz [ 4.304082] stack backtrace: [ 4.304086] CPU: 1 UID: 0 PID: 76 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35 [ 4.304092] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT) [ 4.304097] Workqueue: async async_run_entry_fn [ 4.304106] Call trace: [ 4.304110] show_stack+0x14/0x20 (C) [ 4.304122] dump_stack_lvl+0x6c/0x90 [ 4.304131] dump_stack+0x14/0x1c [ 4.304138] __lock_acquire+0xdfc/0x1584 [ 4.426274] lock_acquire+0x1c4/0x33c [ 4.429942] _raw_spin_lock_irqsave+0x5c/0x80 [ 4.434307] gpio_rcar_config_interrupt_input_mode+0x34/0x164 [ 4.440061] gpio_rcar_irq_set_type+0xd4/0xd8 [ 4.444422] __irq_set_trigger+0x5c/0x178 [ 4.448435] __setup_irq+0x2e4/0x690 [ 4.452012] request_threaded_irq+0xc4/0x190 [ 4.456285] devm_request_threaded_irq+0x7c/0xf4 [ 4.459398] ata1: link resume succeeded after 1 retries [ 4.460902] mmc_gpiod_request_cd_irq+0x68/0xe0 [ 4.470660] mmc_start_host+0x50/0xac [ 4.474327] mmc_add_host+0x80/0xe4 [ 4.477817] tmio_mmc_host_probe+0x2b0/0x440 [ 4.482094] renesas_sdhi_probe+0x488/0x6f4 [ 4.486281] renesas_sdhi_internal_dmac_probe+0x60/0x78 [ 4.491509] platform_probe+0x64/0xd8 [ 4.495178] really_probe+0xb8/0x2a8 [ 4.498756] __driver_probe_device+0x74/0x118 [ 4.503116] driver_probe_device+0x3c/0x154 [ 4.507303] __device_attach_driver+0xd4/0x160 [ 4.511750] bus_for_each_drv+0x84/0xe0 [ 4.515588] __device_attach_async_helper+0xb0/0xdc [ 4.520470] async_run_entry_fn+0x30/0xd8 [ 4.524481] process_one_work+0x210/0x62c [ 4.528494] worker_thread+0x1ac/0x340 [ 4.532245] kthread+0x10c/0x110 [ 4.535476] ret_from_fork+0x10/0x20

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix potential deadloop in prepare_compress_overwrite() Jan Prusakowski reported a kernel hang issue as below: When running xfstests on linux-next kernel (6.14.0-rc3, 6.12) I encountered a problem in generic/475 test where fsstress process gets blocked in __f2fs_write_data_pages() and the test hangs. The options I used are: MKFS_OPTIONS -- -O compression -O extra_attr -O project_quota -O quota /dev/vdc MOUNT_OPTIONS -- -o acl,user_xattr -o discard,compress_extension=* /dev/vdc /vdc INFO: task kworker/u8:0:11 blocked for more than 122 seconds. Not tainted 6.14.0-rc3-xfstests-lockdep #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:0 state:D stack:0 pid:11 tgid:11 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: writeback wb_workfn (flush-253:0) Call Trace: <TASK> __schedule+0x309/0x8e0 schedule+0x3a/0x100 schedule_preempt_disabled+0x15/0x30 __mutex_lock+0x59a/0xdb0 __f2fs_write_data_pages+0x3ac/0x400 do_writepages+0xe8/0x290 __writeback_single_inode+0x5c/0x360 writeback_sb_inodes+0x22f/0x570 wb_writeback+0xb0/0x410 wb_do_writeback+0x47/0x2f0 wb_workfn+0x5a/0x1c0 process_one_work+0x223/0x5b0 worker_thread+0x1d5/0x3c0 kthread+0xfd/0x230 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1a/0x30 </TASK> The root cause is: once generic/475 starts toload error table to dm device, f2fs_prepare_compress_overwrite() will loop reading compressed cluster pages due to IO error, meanwhile it has held .writepages lock, it can block all other writeback tasks. Let's fix this issue w/ below changes: - add f2fs_handle_page_eio() in prepare_compress_overwrite() to detect IO error. - detect cp_error earler in f2fs_read_multi_pages().

In the Linux kernel, the following vulnerability has been resolved: hwpoison, memory_hotplug: lock folio before unmap hwpoisoned folio Commit b15c87263a69 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined) add page poison checks in do_migrate_range in order to make offline hwpoisoned page possible by introducing isolate_lru_page and try_to_unmap for hwpoisoned page. However folio lock must be held before calling try_to_unmap. Add it to fix this problem. Warning will be produced if folio is not locked during unmap: ------------[ cut here ]------------ kernel BUG at ./include/linux/swapops.h:400! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 4 UID: 0 PID: 411 Comm: bash Tainted: G W 6.13.0-rc1-00016-g3c434c7ee82a-dirty #41 Tainted: [W]=WARN Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : try_to_unmap_one+0xb08/0xd3c lr : try_to_unmap_one+0x3dc/0xd3c Call trace: try_to_unmap_one+0xb08/0xd3c (P) try_to_unmap_one+0x3dc/0xd3c (L) rmap_walk_anon+0xdc/0x1f8 rmap_walk+0x3c/0x58 try_to_unmap+0x88/0x90 unmap_poisoned_folio+0x30/0xa8 do_migrate_range+0x4a0/0x568 offline_pages+0x5a4/0x670 memory_block_action+0x17c/0x374 memory_subsys_offline+0x3c/0x78 device_offline+0xa4/0xd0 state_store+0x8c/0xf0 dev_attr_store+0x18/0x2c sysfs_kf_write+0x44/0x54 kernfs_fop_write_iter+0x118/0x1a8 vfs_write+0x3a8/0x4bc ksys_write+0x6c/0xf8 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x44/0x100 el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x30/0xd0 el0t_64_sync_handler+0xc8/0xcc el0t_64_sync+0x198/0x19c Code: f9407be0 b5fff320 d4210000 17ffff97 (d4210000) ---[ end trace 0000000000000000 ]---

In the Linux kernel, the following vulnerability has been resolved: soc: qcom: pdr: Fix the potential deadlock When some client process A call pdr_add_lookup() to add the look up for the service and does schedule locator work, later a process B got a new server packet indicating locator is up and call pdr_locator_new_server() which eventually sets pdr->locator_init_complete to true which process A sees and takes list lock and queries domain list but it will timeout due to deadlock as the response will queued to the same qmi->wq and it is ordered workqueue and process B is not able to complete new server request work due to deadlock on list lock. Fix it by removing the unnecessary list iteration as the list iteration is already being done inside locator work, so avoid it here and just call schedule_work() here. Process A Process B process_scheduled_works() pdr_add_lookup() qmi_data_ready_work() process_scheduled_works() pdr_locator_new_server() pdr->locator_init_complete=true; pdr_locator_work() mutex_lock(&pdr->list_lock); pdr_locate_service() mutex_lock(&pdr->list_lock); pdr_get_domain_list() pr_err("PDR: %s get domain list txn wait failed: %d\n", req->service_name, ret); Timeout error log due to deadlock: " PDR: tms/servreg get domain list txn wait failed: -110 PDR: service lookup for msm/adsp/sensor_pd:tms/servreg failed: -110 " Thanks to Bjorn and Johan for letting me know that this commit also fixes an audio regression when using the in-kernel pd-mapper as that makes it easier to hit this race. [1]

In the Linux kernel, the following vulnerability has been resolved: RDMA/hns: Fix soft lockup during bt pages loop Driver runs a for-loop when allocating bt pages and mapping them with buffer pages. When a large buffer (e.g. MR over 100GB) is being allocated, it may require a considerable loop count. This will lead to soft lockup: watchdog: BUG: soft lockup - CPU#27 stuck for 22s! ... Call trace: hem_list_alloc_mid_bt+0x124/0x394 [hns_roce_hw_v2] hns_roce_hem_list_request+0xf8/0x160 [hns_roce_hw_v2] hns_roce_mtr_create+0x2e4/0x360 [hns_roce_hw_v2] alloc_mr_pbl+0xd4/0x17c [hns_roce_hw_v2] hns_roce_reg_user_mr+0xf8/0x190 [hns_roce_hw_v2] ib_uverbs_reg_mr+0x118/0x290 watchdog: BUG: soft lockup - CPU#35 stuck for 23s! ... Call trace: hns_roce_hem_list_find_mtt+0x7c/0xb0 [hns_roce_hw_v2] mtr_map_bufs+0xc4/0x204 [hns_roce_hw_v2] hns_roce_mtr_create+0x31c/0x3c4 [hns_roce_hw_v2] alloc_mr_pbl+0xb0/0x160 [hns_roce_hw_v2] hns_roce_reg_user_mr+0x108/0x1c0 [hns_roce_hw_v2] ib_uverbs_reg_mr+0x120/0x2bc Add a cond_resched() to fix soft lockup during these loops. In order not to affect the allocation performance of normal-size buffer, set the loop count of a 100GB MR as the threshold to call cond_resched().

In the Linux kernel, the following vulnerability has been resolved: drm: zynqmp_dp: Fix a deadlock in zynqmp_dp_ignore_hpd_set() Instead of attempting the same mutex twice, lock and unlock it. This bug has been detected by the Clang thread-safety analyzer.

In the Linux kernel, the following vulnerability has been resolved: NFS: fix nfs_release_folio() to not deadlock via kcompactd writeback Add PF_KCOMPACTD flag and current_is_kcompactd() helper to check for it so nfs_release_folio() can skip calling nfs_wb_folio() from kcompactd. Otherwise NFS can deadlock waiting for kcompactd enduced writeback which recurses back to NFS (which triggers writeback to NFSD via NFS loopback mount on the same host, NFSD blocks waiting for XFS's call to __filemap_get_folio): 6070.550357] INFO: task kcompactd0:58 blocked for more than 4435 seconds. {--- [58] "kcompactd0" [<0>] folio_wait_bit+0xe8/0x200 [<0>] folio_wait_writeback+0x2b/0x80 [<0>] nfs_wb_folio+0x80/0x1b0 [nfs] [<0>] nfs_release_folio+0x68/0x130 [nfs] [<0>] split_huge_page_to_list_to_order+0x362/0x840 [<0>] migrate_pages_batch+0x43d/0xb90 [<0>] migrate_pages_sync+0x9a/0x240 [<0>] migrate_pages+0x93c/0x9f0 [<0>] compact_zone+0x8e2/0x1030 [<0>] compact_node+0xdb/0x120 [<0>] kcompactd+0x121/0x2e0 [<0>] kthread+0xcf/0x100 [<0>] ret_from_fork+0x31/0x40 [<0>] ret_from_fork_asm+0x1a/0x30 ---} [akpm@linux-foundation.org: fix build]

In the Linux kernel, the following vulnerability has been resolved: drm/imagination: avoid deadlock on fence release Do scheduler queue fence release processing on a workqueue, rather than in the release function itself. Fixes deadlock issues such as the following: [ 607.400437] ============================================ [ 607.405755] WARNING: possible recursive locking detected [ 607.415500] -------------------------------------------- [ 607.420817] weston:zfq0/24149 is trying to acquire lock: [ 607.426131] ffff000017d041a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: pvr_gem_object_vunmap+0x40/0xc0 [powervr] [ 607.436728] but task is already holding lock: [ 607.442554] ffff000017d105a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: dma_buf_ioctl+0x250/0x554 [ 607.451727] other info that might help us debug this: [ 607.458245] Possible unsafe locking scenario: [ 607.464155] CPU0 [ 607.466601] ---- [ 607.469044] lock(reservation_ww_class_mutex); [ 607.473584] lock(reservation_ww_class_mutex); [ 607.478114] *** DEADLOCK ***

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix bug on trap in smb2_lock If lock count is greater than 1, flags could be old value. It should be checked with flags of smb_lock, not flags. It will cause bug-on trap from locks_free_lock in error handling routine.

In the Linux kernel, the following vulnerability has been resolved: net: ibmveth: make veth_pool_store stop hanging v2: - Created a single error handling unlock and exit in veth_pool_store - Greatly expanded commit message with previous explanatory-only text Summary: Use rtnl_mutex to synchronize veth_pool_store with itself, ibmveth_close and ibmveth_open, preventing multiple calls in a row to napi_disable. Background: Two (or more) threads could call veth_pool_store through writing to /sys/devices/vio/30000002/pool*/*. You can do this easily with a little shell script. This causes a hang. I configured LOCKDEP, compiled ibmveth.c with DEBUG, and built a new kernel. I ran this test again and saw: Setting pool0/active to 0 Setting pool1/active to 1 [ 73.911067][ T4365] ibmveth 30000002 eth0: close starting Setting pool1/active to 1 Setting pool1/active to 0 [ 73.911367][ T4366] ibmveth 30000002 eth0: close starting [ 73.916056][ T4365] ibmveth 30000002 eth0: close complete [ 73.916064][ T4365] ibmveth 30000002 eth0: open starting [ 110.808564][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification. [ 230.808495][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification. [ 243.683786][ T123] INFO: task stress.sh:4365 blocked for more than 122 seconds. [ 243.683827][ T123] Not tainted 6.14.0-01103-g2df0c02dab82-dirty #8 [ 243.683833][ T123] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 243.683838][ T123] task:stress.sh state:D stack:28096 pid:4365 tgid:4365 ppid:4364 task_flags:0x400040 flags:0x00042000 [ 243.683852][ T123] Call Trace: [ 243.683857][ T123] [c00000000c38f690] [0000000000000001] 0x1 (unreliable) [ 243.683868][ T123] [c00000000c38f840] [c00000000001f908] __switch_to+0x318/0x4e0 [ 243.683878][ T123] [c00000000c38f8a0] [c000000001549a70] __schedule+0x500/0x12a0 [ 243.683888][ T123] [c00000000c38f9a0] [c00000000154a878] schedule+0x68/0x210 [ 243.683896][ T123] [c00000000c38f9d0] [c00000000154ac80] schedule_preempt_disabled+0x30/0x50 [ 243.683904][ T123] [c00000000c38fa00] [c00000000154dbb0] __mutex_lock+0x730/0x10f0 [ 243.683913][ T123] [c00000000c38fb10] [c000000001154d40] napi_enable+0x30/0x60 [ 243.683921][ T123] [c00000000c38fb40] [c000000000f4ae94] ibmveth_open+0x68/0x5dc [ 243.683928][ T123] [c00000000c38fbe0] [c000000000f4aa20] veth_pool_store+0x220/0x270 [ 243.683936][ T123] [c00000000c38fc70] [c000000000826278] sysfs_kf_write+0x68/0xb0 [ 243.683944][ T123] [c00000000c38fcb0] [c0000000008240b8] kernfs_fop_write_iter+0x198/0x2d0 [ 243.683951][ T123] [c00000000c38fd00] [c00000000071b9ac] vfs_write+0x34c/0x650 [ 243.683958][ T123] [c00000000c38fdc0] [c00000000071bea8] ksys_write+0x88/0x150 [ 243.683966][ T123] [c00000000c38fe10] [c0000000000317f4] system_call_exception+0x124/0x340 [ 243.683973][ T123] [c00000000c38fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec ... [ 243.684087][ T123] Showing all locks held in the system: [ 243.684095][ T123] 1 lock held by khungtaskd/123: [ 243.684099][ T123] #0: c00000000278e370 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x50/0x248 [ 243.684114][ T123] 4 locks held by stress.sh/4365: [ 243.684119][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150 [ 243.684132][ T123] #1: c000000041aea888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0 [ 243.684143][ T123] #2: c0000000366fb9a8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0 [ 243.684155][ T123] #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_enable+0x30/0x60 [ 243.684166][ T123] 5 locks held by stress.sh/4366: [ 243.684170][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150 [ 243. ---truncated---

In the Linux kernel, the following vulnerability has been resolved: NFSv4: Fix a deadlock when recovering state on a sillyrenamed file If the file is sillyrenamed, and slated for delete on close, it is possible for a server reboot to triggeer an open reclaim, with can again race with the application call to close(). When that happens, the call to put_nfs_open_context() can trigger a synchronous delegreturn call which deadlocks because it is not marked as privileged. Instead, ensure that the call to nfs4_inode_return_delegation_on_close() catches the delegreturn, and schedules it asynchronously.

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix pick_task_scx() picking non-queued tasks when it's called without balance() a6250aa251ea ("sched_ext: Handle cases where pick_task_scx() is called without preceding balance_scx()") added a workaround to handle the cases where pick_task_scx() is called without prececing balance_scx() which is due to a fair class bug where pick_taks_fair() may return NULL after a true return from balance_fair(). The workaround detects when pick_task_scx() is called without preceding balance_scx() and emulates SCX_RQ_BAL_KEEP and triggers kicking to avoid stalling. Unfortunately, the workaround code was testing whether @prev was on SCX to decide whether to keep the task running. This is incorrect as the task may be on SCX but no longer runnable. This could lead to a non-runnable task to be returned from pick_task_scx() which cause interesting confusions and failures. e.g. A common failure mode is the task ending up with (!on_rq && on_cpu) state which can cause potential wakers to busy loop, which can easily lead to deadlocks. Fix it by testing whether @prev has SCX_TASK_QUEUED set. This makes @prev_on_scx only used in one place. Open code the usage and improve the comment while at it.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix inversion dependency warning while enabling IPsec tunnel Attempt to enable IPsec packet offload in tunnel mode in debug kernel generates the following kernel panic, which is happening due to two issues: 1. In SA add section, the should be _bh() variant when marking SA mode. 2. There is not needed flush_workqueue in SA delete routine. It is not needed as at this stage as it is removed from SADB and the running work will be canceled later in SA free. ===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 6.12.0+ #4 Not tainted ----------------------------------------------------- charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire: ffff88810f365020 (&xa->xa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core] and this task is already holding: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30 which would create a new lock dependency: (&x->lock){+.-.}-{3:3} -> (&xa->xa_lock#24){+.+.}-{3:3} but this new dependency connects a SOFTIRQ-irq-safe lock: (&x->lock){+.-.}-{3:3} ... which became SOFTIRQ-irq-safe at: lock_acquire+0x1be/0x520 _raw_spin_lock_bh+0x34/0x40 xfrm_timer_handler+0x91/0xd70 __hrtimer_run_queues+0x1dd/0xa60 hrtimer_run_softirq+0x146/0x2e0 handle_softirqs+0x266/0x860 irq_exit_rcu+0x115/0x1a0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x16/0x20 default_idle+0x13/0x20 default_idle_call+0x67/0xa0 do_idle+0x2da/0x320 cpu_startup_entry+0x50/0x60 start_secondary+0x213/0x2a0 common_startup_64+0x129/0x138 to a SOFTIRQ-irq-unsafe lock: (&xa->xa_lock#24){+.+.}-{3:3} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0x1be/0x520 _raw_spin_lock+0x2c/0x40 xa_set_mark+0x70/0x110 mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core] xfrm_dev_state_add+0x3bb/0xd70 xfrm_add_sa+0x2451/0x4a90 xfrm_user_rcv_msg+0x493/0x880 netlink_rcv_skb+0x12e/0x380 xfrm_netlink_rcv+0x6d/0x90 netlink_unicast+0x42f/0x740 netlink_sendmsg+0x745/0xbe0 __sock_sendmsg+0xc5/0x190 __sys_sendto+0x1fe/0x2c0 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&xa->xa_lock#24); local_irq_disable(); lock(&x->lock); lock(&xa->xa_lock#24); <Interrupt> lock(&x->lock); *** DEADLOCK *** 2 locks held by charon/1337: #0: ffffffff87f8f858 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90 #1: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&x->lock){+.-.}-{3:3} ops: 29 { HARDIRQ-ON-W at: lock_acquire+0x1be/0x520 _raw_spin_lock_bh+0x34/0x40 xfrm_alloc_spi+0xc0/0xe60 xfrm_alloc_userspi+0x5f6/0xbc0 xfrm_user_rcv_msg+0x493/0x880 netlink_rcv_skb+0x12e/0x380 xfrm_netlink_rcv+0x6d/0x90 netlink_unicast+0x42f/0x740 netlink_sendmsg+0x745/0xbe0 __sock_sendmsg+0xc5/0x190 __sys_sendto+0x1fe/0x2c0 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 IN-SOFTIRQ-W at: lock_acquire+0x1be/0x520 _raw_spin_lock_bh+0x34/0x40 xfrm_timer_handler+0x91/0xd70 __hrtimer_run_queues+0x1dd/0xa60 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: USB: gadget: f_midi: f_midi_complete to call queue_work When using USB MIDI, a lock is attempted to be acquired twice through a re-entrant call to f_midi_transmit, causing a deadlock. Fix it by using queue_work() to schedule the inner f_midi_transmit() via a high priority work queue from the completion handler.

In the Linux kernel, the following vulnerability has been resolved: tty: xilinx_uartps: split sysrq handling lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock.

In the Linux kernel, the following vulnerability has been resolved: net: rose: lock the socket in rose_bind() syzbot reported a soft lockup in rose_loopback_timer(), with a repro calling bind() from multiple threads. rose_bind() must lock the socket to avoid this issue.

In the Linux kernel, the following vulnerability has been resolved: gpio: xilinx: Convert gpio_lock to raw spinlock irq_chip functions may be called in raw spinlock context. Therefore, we must also use a raw spinlock for our own internal locking. This fixes the following lockdep splat: [ 5.349336] ============================= [ 5.353349] [ BUG: Invalid wait context ] [ 5.357361] 6.13.0-rc5+ #69 Tainted: G W [ 5.363031] ----------------------------- [ 5.367045] kworker/u17:1/44 is trying to lock: [ 5.371587] ffffff88018b02c0 (&chip->gpio_lock){....}-{3:3}, at: xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8)) [ 5.380079] other info that might help us debug this: [ 5.385138] context-{5:5} [ 5.387762] 5 locks held by kworker/u17:1/44: [ 5.392123] #0: ffffff8800014958 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3204) [ 5.402260] #1: ffffffc082fcbdd8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3205) [ 5.411528] #2: ffffff880172c900 (&dev->mutex){....}-{4:4}, at: __device_attach (drivers/base/dd.c:1006) [ 5.419929] #3: ffffff88039c8268 (request_class#2){+.+.}-{4:4}, at: __setup_irq (kernel/irq/internals.h:156 kernel/irq/manage.c:1596) [ 5.428331] #4: ffffff88039c80c8 (lock_class#2){....}-{2:2}, at: __setup_irq (kernel/irq/manage.c:1614) [ 5.436472] stack backtrace: [ 5.439359] CPU: 2 UID: 0 PID: 44 Comm: kworker/u17:1 Tainted: G W 6.13.0-rc5+ #69 [ 5.448690] Tainted: [W]=WARN [ 5.451656] Hardware name: xlnx,zynqmp (DT) [ 5.455845] Workqueue: events_unbound deferred_probe_work_func [ 5.461699] Call trace: [ 5.464147] show_stack+0x18/0x24 C [ 5.467821] dump_stack_lvl (lib/dump_stack.c:123) [ 5.471501] dump_stack (lib/dump_stack.c:130) [ 5.474824] __lock_acquire (kernel/locking/lockdep.c:4828 kernel/locking/lockdep.c:4898 kernel/locking/lockdep.c:5176) [ 5.478758] lock_acquire (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851 kernel/locking/lockdep.c:5814) [ 5.482429] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162) [ 5.486797] xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8)) [ 5.490737] irq_enable (kernel/irq/internals.h:236 kernel/irq/chip.c:170 kernel/irq/chip.c:439 kernel/irq/chip.c:432 kernel/irq/chip.c:345) [ 5.494060] __irq_startup (kernel/irq/internals.h:241 kernel/irq/chip.c:180 kernel/irq/chip.c:250) [ 5.497645] irq_startup (kernel/irq/chip.c:270) [ 5.501143] __setup_irq (kernel/irq/manage.c:1807) [ 5.504728] request_threaded_irq (kernel/irq/manage.c:2208)

In the Linux kernel, the following vulnerability has been resolved: tcp: correct handling of extreme memory squeeze Testing with iperf3 using the "pasta" protocol splicer has revealed a problem in the way tcp handles window advertising in extreme memory squeeze situations. Under memory pressure, a socket endpoint may temporarily advertise a zero-sized window, but this is not stored as part of the socket data. The reasoning behind this is that it is considered a temporary setting which shouldn't influence any further calculations. However, if we happen to stall at an unfortunate value of the current window size, the algorithm selecting a new value will consistently fail to advertise a non-zero window once we have freed up enough memory. This means that this side's notion of the current window size is different from the one last advertised to the peer, causing the latter to not send any data to resolve the sitution. The problem occurs on the iperf3 server side, and the socket in question is a completely regular socket with the default settings for the fedora40 kernel. We do not use SO_PEEK or SO_RCVBUF on the socket. The following excerpt of a logging session, with own comments added, shows more in detail what is happening: // tcp_v4_rcv(->) // tcp_rcv_established(->) [5201<->39222]: ==== Activating log @ net/ipv4/tcp_input.c/tcp_data_queue()/5257 ==== [5201<->39222]: tcp_data_queue(->) [5201<->39222]: DROPPING skb [265600160..265665640], reason: SKB_DROP_REASON_PROTO_MEM [rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184] [copied_seq 259909392->260034360 (124968), unread 5565800, qlen 85, ofoq 0] [OFO queue: gap: 65480, len: 0] [5201<->39222]: tcp_data_queue(<-) [5201<->39222]: __tcp_transmit_skb(->) [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] [5201<->39222]: tcp_select_window(->) [5201<->39222]: (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_NOMEM) ? --> TRUE [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] returning 0 [5201<->39222]: tcp_select_window(<-) [5201<->39222]: ADVERTISING WIN 0, ACK_SEQ: 265600160 [5201<->39222]: [__tcp_transmit_skb(<-) [5201<->39222]: tcp_rcv_established(<-) [5201<->39222]: tcp_v4_rcv(<-) // Receive queue is at 85 buffers and we are out of memory. // We drop the incoming buffer, although it is in sequence, and decide // to send an advertisement with a window of zero. // We don't update tp->rcv_wnd and tp->rcv_wup accordingly, which means // we unconditionally shrink the window. [5201<->39222]: tcp_recvmsg_locked(->) [5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160 [5201<->39222]: [new_win = 0, win_now = 131184, 2 * win_now = 262368] [5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0] [5201<->39222]: NOT calling tcp_send_ack() [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] [5201<->39222]: __tcp_cleanup_rbuf(<-) [rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184] [copied_seq 260040464->260040464 (0), unread 5559696, qlen 85, ofoq 0] returning 6104 bytes [5201<->39222]: tcp_recvmsg_locked(<-) // After each read, the algorithm for calculating the new receive // window in __tcp_cleanup_rbuf() finds it is too small to advertise // or to update tp->rcv_wnd. // Meanwhile, the peer thinks the window is zero, and will not send // any more data to trigger an update from the interrupt mode side. [5201<->39222]: tcp_recvmsg_locked(->) [5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160 [5201<->39222]: [new_win = 262144, win_now = 131184, 2 * win_n ---truncated---

In the Linux kernel, the following vulnerability has been resolved: drm/i915/gt: Use spin_lock_irqsave() in interruptible context spin_lock/unlock() functions used in interrupt contexts could result in a deadlock, as seen in GitLab issue #13399, which occurs when interrupt comes in while holding a lock. Try to remedy the problem by saving irq state before spin lock acquisition. v2: add irqs' state save/restore calls to all locks/unlocks in signal_irq_work() execution (Maciej) v3: use with spin_lock_irqsave() in guc_lrc_desc_unpin() instead of other lock/unlock calls and add Fixes and Cc tags (Tvrtko); change title and commit message (cherry picked from commit c088387ddd6482b40f21ccf23db1125e8fa4af7e)

In the Linux kernel, the following vulnerability has been resolved: block: fix queue freeze vs limits lock order in sysfs store methods queue_attr_store() always freezes a device queue before calling the attribute store operation. For attributes that control queue limits, the store operation will also lock the queue limits with a call to queue_limits_start_update(). However, some drivers (e.g. SCSI sd) may need to issue commands to a device to obtain limit values from the hardware with the queue limits locked. This creates a potential ABBA deadlock situation if a user attempts to modify a limit (thus freezing the device queue) while the device driver starts a revalidation of the device queue limits. Avoid such deadlock by not freezing the queue before calling the ->store_limit() method in struct queue_sysfs_entry and instead use the queue_limits_commit_update_frozen helper to freeze the queue after taking the limits lock. This also removes taking the sysfs lock for the store_limit method as it doesn't protect anything here, but creates even more nesting. Hopefully it will go away from the actual sysfs methods entirely soon. (commit log adapted from a similar patch from Damien Le Moal)

In the Linux kernel, the following vulnerability has been resolved: block: mark GFP_NOIO around sysfs ->store() sysfs ->store is called with queue freezed, meantime we have several ->store() callbacks(update_nr_requests, wbt, scheduler) to allocate memory with GFP_KERNEL which may run into direct reclaim code path, then potential deadlock can be caused. Fix the issue by marking NOIO around sysfs ->store()

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface() The documentation for usb_driver_claim_interface() says that "the device lock" is needed when the function is called from places other than probe(). This appears to be the lock for the USB interface device. The Mediatek btusb code gets called via this path: Workqueue: hci0 hci_power_on [bluetooth] Call trace: usb_driver_claim_interface btusb_mtk_claim_iso_intf btusb_mtk_setup hci_dev_open_sync hci_power_on process_scheduled_works worker_thread kthread With the above call trace the device lock hasn't been claimed. Claim it. Without this fix, we'd sometimes see the error "Failed to claim iso interface". Sometimes we'd even see worse errors, like a NULL pointer dereference (where `intf->dev.driver` was NULL) with a trace like: Call trace: usb_suspend_both usb_runtime_suspend __rpm_callback rpm_suspend pm_runtime_work process_scheduled_works Both errors appear to be fixed with the proper locking.

In the Linux kernel, the following vulnerability has been resolved: rxrpc, afs: Fix peer hash locking vs RCU callback In its address list, afs now retains pointers to and refs on one or more rxrpc_peer objects. The address list is freed under RCU and at this time, it puts the refs on those peers. Now, when an rxrpc_peer object runs out of refs, it gets removed from the peer hash table and, for that, rxrpc has to take a spinlock. However, it is now being called from afs's RCU cleanup, which takes place in BH context - but it is just taking an ordinary spinlock. The put may also be called from non-BH context, and so there exists the possibility of deadlock if the BH-based RCU cleanup happens whilst the hash spinlock is held. This led to the attached lockdep complaint. Fix this by changing spinlocks of rxnet->peer_hash_lock back to BH-disabling locks. ================================ WARNING: inconsistent lock state 6.13.0-rc5-build2+ #1223 Tainted: G E -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff88810babe228 (&rxnet->peer_hash_lock){+.?.}-{3:3}, at: rxrpc_put_peer+0xcb/0x180 {SOFTIRQ-ON-W} state was registered at: mark_usage+0x164/0x180 __lock_acquire+0x544/0x990 lock_acquire.part.0+0x103/0x280 _raw_spin_lock+0x2f/0x40 rxrpc_peer_keepalive_worker+0x144/0x440 process_one_work+0x486/0x7c0 process_scheduled_works+0x73/0x90 worker_thread+0x1c8/0x2a0 kthread+0x19b/0x1b0 ret_from_fork+0x24/0x40 ret_from_fork_asm+0x1a/0x30 irq event stamp: 972402 hardirqs last enabled at (972402): [<ffffffff8244360e>] _raw_spin_unlock_irqrestore+0x2e/0x50 hardirqs last disabled at (972401): [<ffffffff82443328>] _raw_spin_lock_irqsave+0x18/0x60 softirqs last enabled at (972300): [<ffffffff810ffbbe>] handle_softirqs+0x3ee/0x430 softirqs last disabled at (972313): [<ffffffff810ffc54>] __irq_exit_rcu+0x44/0x110 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&rxnet->peer_hash_lock); <Interrupt> lock(&rxnet->peer_hash_lock); *** DEADLOCK *** 1 lock held by swapper/1/0: #0: ffffffff83576be0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire+0x7/0x30 stack backtrace: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G E 6.13.0-rc5-build2+ #1223 Tainted: [E]=UNSIGNED_MODULE Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Call Trace: <IRQ> dump_stack_lvl+0x57/0x80 print_usage_bug.part.0+0x227/0x240 valid_state+0x53/0x70 mark_lock_irq+0xa5/0x2f0 mark_lock+0xf7/0x170 mark_usage+0xe1/0x180 __lock_acquire+0x544/0x990 lock_acquire.part.0+0x103/0x280 _raw_spin_lock+0x2f/0x40 rxrpc_put_peer+0xcb/0x180 afs_free_addrlist+0x46/0x90 [kafs] rcu_do_batch+0x2d2/0x640 rcu_core+0x2f7/0x350 handle_softirqs+0x1ee/0x430 __irq_exit_rcu+0x44/0x110 irq_exit_rcu+0xa/0x30 sysvec_apic_timer_interrupt+0x7f/0xa0 </IRQ>

In the Linux kernel, the following vulnerability has been resolved: dma-debug: don't call __dma_entry_alloc_check_leak() under free_entries_lock __dma_entry_alloc_check_leak() calls into printk -> serial console output (qcom geni) and grabs port->lock under free_entries_lock spin lock, which is a reverse locking dependency chain as qcom_geni IRQ handler can call into dma-debug code and grab free_entries_lock under port->lock. Move __dma_entry_alloc_check_leak() call out of free_entries_lock scope so that we don't acquire serial console's port->lock under it. Trimmed-down lockdep splat: The existing dependency chain (in reverse order) is: -> #2 (free_entries_lock){-.-.}-{2:2}: _raw_spin_lock_irqsave+0x60/0x80 dma_entry_alloc+0x38/0x110 debug_dma_map_page+0x60/0xf8 dma_map_page_attrs+0x1e0/0x230 dma_map_single_attrs.constprop.0+0x6c/0xc8 geni_se_rx_dma_prep+0x40/0xcc qcom_geni_serial_isr+0x310/0x510 __handle_irq_event_percpu+0x110/0x244 handle_irq_event_percpu+0x20/0x54 handle_irq_event+0x50/0x88 handle_fasteoi_irq+0xa4/0xcc handle_irq_desc+0x28/0x40 generic_handle_domain_irq+0x24/0x30 gic_handle_irq+0xc4/0x148 do_interrupt_handler+0xa4/0xb0 el1_interrupt+0x34/0x64 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x64/0x68 arch_local_irq_enable+0x4/0x8 ____do_softirq+0x18/0x24 ... -> #1 (&port_lock_key){-.-.}-{2:2}: _raw_spin_lock_irqsave+0x60/0x80 qcom_geni_serial_console_write+0x184/0x1dc console_flush_all+0x344/0x454 console_unlock+0x94/0xf0 vprintk_emit+0x238/0x24c vprintk_default+0x3c/0x48 vprintk+0xb4/0xbc _printk+0x68/0x90 register_console+0x230/0x38c uart_add_one_port+0x338/0x494 qcom_geni_serial_probe+0x390/0x424 platform_probe+0x70/0xc0 really_probe+0x148/0x280 __driver_probe_device+0xfc/0x114 driver_probe_device+0x44/0x100 __device_attach_driver+0x64/0xdc bus_for_each_drv+0xb0/0xd8 __device_attach+0xe4/0x140 device_initial_probe+0x1c/0x28 bus_probe_device+0x44/0xb0 device_add+0x538/0x668 of_device_add+0x44/0x50 of_platform_device_create_pdata+0x94/0xc8 of_platform_bus_create+0x270/0x304 of_platform_populate+0xac/0xc4 devm_of_platform_populate+0x60/0xac geni_se_probe+0x154/0x160 platform_probe+0x70/0xc0 ... -> #0 (console_owner){-...}-{0:0}: __lock_acquire+0xdf8/0x109c lock_acquire+0x234/0x284 console_flush_all+0x330/0x454 console_unlock+0x94/0xf0 vprintk_emit+0x238/0x24c vprintk_default+0x3c/0x48 vprintk+0xb4/0xbc _printk+0x68/0x90 dma_entry_alloc+0xb4/0x110 debug_dma_map_sg+0xdc/0x2f8 __dma_map_sg_attrs+0xac/0xe4 dma_map_sgtable+0x30/0x4c get_pages+0x1d4/0x1e4 [msm] msm_gem_pin_pages_locked+0x38/0xac [msm] msm_gem_pin_vma_locked+0x58/0x88 [msm] msm_ioctl_gem_submit+0xde4/0x13ac [msm] drm_ioctl_kernel+0xe0/0x15c drm_ioctl+0x2e8/0x3f4 vfs_ioctl+0x30/0x50 ... Chain exists of: console_owner --> &port_lock_key --> free_entries_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(free_entries_lock); lock(&port_lock_key); lock(free_entries_lock); lock(console_owner); *** DEADLOCK *** Call trace: dump_backtrace+0xb4/0xf0 show_stack+0x20/0x30 dump_stack_lvl+0x60/0x84 dump_stack+0x18/0x24 print_circular_bug+0x1cc/0x234 check_noncircular+0x78/0xac __lock_acquire+0xdf8/0x109c lock_acquire+0x234/0x284 console_flush_all+0x330/0x454 consol ---truncated---

In the Linux kernel, the following vulnerability has been resolved: clk: Get runtime PM before walking tree for clk_summary Similar to the previous commit, we should make sure that all devices are runtime resumed before printing the clk_summary through debugfs. Failure to do so would result in a deadlock if the thread is resuming a device to print clk state and that device is also runtime resuming in another thread, e.g the screen is turning on and the display driver is starting up. We remove the calls to clk_pm_runtime_{get,put}() in this path because they're superfluous now that we know the devices are runtime resumed. This also squashes a bug where the return value of clk_pm_runtime_get() wasn't checked, leading to an RPM count underflow on error paths.