In the Linux kernel, the following vulnerability has been resolved: mac80211: fix locking in ieee80211_start_ap error path We need to hold the local->mtx to release the channel context, as even encoded by the lockdep_assert_held() there. Fix it.

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix soft lockup during fsstress Below traces are observed during fsstress and system got hung. [ 130.698396] watchdog: BUG: soft lockup - CPU#6 stuck for 26s!

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: avoid deadlock between hci_dev->lock and socket lock Commit eab2404ba798 ("Bluetooth: Add BT_PHY socket option") added a dependency between socket lock and hci_dev->lock that could lead to deadlock. It turns out that hci_conn_get_phy() is not in any way relying on hdev being immutable during the runtime of this function, neither does it even look at any of the members of hdev, and as such there is no need to hold that lock. This fixes the lockdep splat below: ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc1-00026-g73d464503354 #10 Not tainted ------------------------------------------------------ bluetoothd/1118 is trying to acquire lock: ffff8f078383c078 (&hdev->lock){+.+.}-{3:3}, at: hci_conn_get_phy+0x1c/0x150 [bluetooth] but task is already holding lock: ffff8f07e831d920 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: l2cap_sock_getsockopt+0x8b/0x610 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}: lock_sock_nested+0x72/0xa0 l2cap_sock_ready_cb+0x18/0x70 [bluetooth] l2cap_config_rsp+0x27a/0x520 [bluetooth] l2cap_sig_channel+0x658/0x1330 [bluetooth] l2cap_recv_frame+0x1ba/0x310 [bluetooth] hci_rx_work+0x1cc/0x640 [bluetooth] process_one_work+0x244/0x5f0 worker_thread+0x3c/0x380 kthread+0x13e/0x160 ret_from_fork+0x22/0x30 -> #2 (&chan->lock#2/1){+.+.}-{3:3}: __mutex_lock+0xa3/0xa10 l2cap_chan_connect+0x33a/0x940 [bluetooth] l2cap_sock_connect+0x141/0x2a0 [bluetooth] __sys_connect+0x9b/0xc0 __x64_sys_connect+0x16/0x20 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #1 (&conn->chan_lock){+.+.}-{3:3}: __mutex_lock+0xa3/0xa10 l2cap_chan_connect+0x322/0x940 [bluetooth] l2cap_sock_connect+0x141/0x2a0 [bluetooth] __sys_connect+0x9b/0xc0 __x64_sys_connect+0x16/0x20 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&hdev->lock){+.+.}-{3:3}: __lock_acquire+0x147a/0x1a50 lock_acquire+0x277/0x3d0 __mutex_lock+0xa3/0xa10 hci_conn_get_phy+0x1c/0x150 [bluetooth] l2cap_sock_getsockopt+0x5a9/0x610 [bluetooth] __sys_getsockopt+0xcc/0x200 __x64_sys_getsockopt+0x20/0x30 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: &hdev->lock --> &chan->lock#2/1 --> sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); lock(&chan->lock#2/1); lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP); lock(&hdev->lock); *** DEADLOCK *** 1 lock held by bluetoothd/1118: #0: ffff8f07e831d920 (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+.}-{0:0}, at: l2cap_sock_getsockopt+0x8b/0x610 [bluetooth] stack backtrace: CPU: 3 PID: 1118 Comm: bluetoothd Not tainted 5.12.0-rc1-00026-g73d464503354 #10 Hardware name: LENOVO 20K5S22R00/20K5S22R00, BIOS R0IET38W (1.16 ) 05/31/2017 Call Trace: dump_stack+0x7f/0xa1 check_noncircular+0x105/0x120 ? __lock_acquire+0x147a/0x1a50 __lock_acquire+0x147a/0x1a50 lock_acquire+0x277/0x3d0 ? hci_conn_get_phy+0x1c/0x150 [bluetooth] ? __lock_acquire+0x2e1/0x1a50 ? lock_is_held_type+0xb4/0x120 ? hci_conn_get_phy+0x1c/0x150 [bluetooth] __mutex_lock+0xa3/0xa10 ? hci_conn_get_phy+0x1c/0x150 [bluetooth] ? lock_acquire+0x277/0x3d0 ? mark_held_locks+0x49/0x70 ? mark_held_locks+0x49/0x70 ? hci_conn_get_phy+0x1c/0x150 [bluetooth] hci_conn_get_phy+0x ---truncated---

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: fix incorrect locking in state_change sk callback We are not changing anything in the TCP connection state so we should not take a write_lock but rather a read lock. This caused a deadlock when running nvmet-tcp and nvme-tcp on the same system, where state_change callbacks on the host and on the controller side have causal relationship and made lockdep report on this with blktests: ================================ WARNING: inconsistent lock state 5.12.0-rc3 #1 Tainted: G I -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-R} usage. nvme/1324 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff888363151000 (clock-AF_INET){++-?}-{2:2}, at: nvme_tcp_state_change+0x21/0x150 [nvme_tcp] {IN-SOFTIRQ-W} state was registered at: __lock_acquire+0x79b/0x18d0 lock_acquire+0x1ca/0x480 _raw_write_lock_bh+0x39/0x80 nvmet_tcp_state_change+0x21/0x170 [nvmet_tcp] tcp_fin+0x2a8/0x780 tcp_data_queue+0xf94/0x1f20 tcp_rcv_established+0x6ba/0x1f00 tcp_v4_do_rcv+0x502/0x760 tcp_v4_rcv+0x257e/0x3430 ip_protocol_deliver_rcu+0x69/0x6a0 ip_local_deliver_finish+0x1e2/0x2f0 ip_local_deliver+0x1a2/0x420 ip_rcv+0x4fb/0x6b0 __netif_receive_skb_one_core+0x162/0x1b0 process_backlog+0x1ff/0x770 __napi_poll.constprop.0+0xa9/0x5c0 net_rx_action+0x7b3/0xb30 __do_softirq+0x1f0/0x940 do_softirq+0xa1/0xd0 __local_bh_enable_ip+0xd8/0x100 ip_finish_output2+0x6b7/0x18a0 __ip_queue_xmit+0x706/0x1aa0 __tcp_transmit_skb+0x2068/0x2e20 tcp_write_xmit+0xc9e/0x2bb0 __tcp_push_pending_frames+0x92/0x310 inet_shutdown+0x158/0x300 __nvme_tcp_stop_queue+0x36/0x270 [nvme_tcp] nvme_tcp_stop_queue+0x87/0xb0 [nvme_tcp] nvme_tcp_teardown_admin_queue+0x69/0xe0 [nvme_tcp] nvme_do_delete_ctrl+0x100/0x10c [nvme_core] nvme_sysfs_delete.cold+0x8/0xd [nvme_core] kernfs_fop_write_iter+0x2c7/0x460 new_sync_write+0x36c/0x610 vfs_write+0x5c0/0x870 ksys_write+0xf9/0x1d0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae irq event stamp: 10687 hardirqs last enabled at (10687): [<ffffffff9ec376bd>] _raw_spin_unlock_irqrestore+0x2d/0x40 hardirqs last disabled at (10686): [<ffffffff9ec374d8>] _raw_spin_lock_irqsave+0x68/0x90 softirqs last enabled at (10684): [<ffffffff9f000608>] __do_softirq+0x608/0x940 softirqs last disabled at (10649): [<ffffffff9cdedd31>] do_softirq+0xa1/0xd0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(clock-AF_INET); <Interrupt> lock(clock-AF_INET); *** DEADLOCK *** 5 locks held by nvme/1324: #0: ffff8884a01fe470 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0xf9/0x1d0 #1: ffff8886e435c090 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x216/0x460 #2: ffff888104d90c38 (kn->active#255){++++}-{0:0}, at: kernfs_remove_self+0x22d/0x330 #3: ffff8884634538d0 (&queue->queue_lock){+.+.}-{3:3}, at: nvme_tcp_stop_queue+0x52/0xb0 [nvme_tcp] #4: ffff888363150d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_shutdown+0x59/0x300 stack backtrace: CPU: 26 PID: 1324 Comm: nvme Tainted: G I 5.12.0-rc3 #1 Hardware name: Dell Inc. PowerEdge R640/06NR82, BIOS 2.10.0 11/12/2020 Call Trace: dump_stack+0x93/0xc2 mark_lock_irq.cold+0x2c/0xb3 ? verify_lock_unused+0x390/0x390 ? stack_trace_consume_entry+0x160/0x160 ? lock_downgrade+0x100/0x100 ? save_trace+0x88/0x5e0 ? _raw_spin_unlock_irqrestore+0x2d/0x40 mark_lock+0x530/0x1470 ? mark_lock_irq+0x1d10/0x1d10 ? enqueue_timer+0x660/0x660 mark_usage+0x215/0x2a0 __lock_acquire+0x79b/0x18d0 ? tcp_schedule_loss_probe.part.0+0x38c/0x520 lock_acquire+0x1ca/0x480 ? nvme_tcp_state_change+0x21/0x150 [nvme_tcp] ? rcu_read_unlock+0x40/0x40 ? tcp_mtu_probe+0x1ae0/0x1ae0 ? kmalloc_reserve+0xa0/0xa0 ? sysfs_file_ops+0x170/0x170 _raw_read_lock+0x3d/0xa0 ? nvme_tcp_state_change+0x21/0x150 [nvme_tcp] nvme_tcp_state_change+0x21/0x150 [nvme_tcp] ? sysfs_file_ops ---truncated---

In the Linux kernel, the following vulnerability has been resolved: nitro_enclaves: Use get_user_pages_unlocked() call to handle mmap assert After commit 5b78ed24e8ec ("mm/pagemap: add mmap_assert_locked() annotations to find_vma*()"), the call to get_user_pages() will trigger the mmap assert. static inline void mmap_assert_locked(struct mm_struct *mm) { lockdep_assert_held(&mm->mmap_lock); VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm); } [ 62.521410] kernel BUG at include/linux/mmap_lock.h:156! ........................................................... [ 62.538938] RIP: 0010:find_vma+0x32/0x80 ........................................................... [ 62.605889] Call Trace: [ 62.608502] <TASK> [ 62.610956] ? lock_timer_base+0x61/0x80 [ 62.614106] find_extend_vma+0x19/0x80 [ 62.617195] __get_user_pages+0x9b/0x6a0 [ 62.620356] __gup_longterm_locked+0x42d/0x450 [ 62.623721] ? finish_wait+0x41/0x80 [ 62.626748] ? __kmalloc+0x178/0x2f0 [ 62.629768] ne_set_user_memory_region_ioctl.isra.0+0x225/0x6a0 [nitro_enclaves] [ 62.635776] ne_enclave_ioctl+0x1cf/0x6d7 [nitro_enclaves] [ 62.639541] __x64_sys_ioctl+0x82/0xb0 [ 62.642620] do_syscall_64+0x3b/0x90 [ 62.645642] entry_SYSCALL_64_after_hwframe+0x44/0xae Use get_user_pages_unlocked() when setting the enclave memory regions. That's a similar pattern as mmap_read_lock() used together with get_user_pages().

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix deadlock when cloning inline extents and using qgroups There are a few exceptional cases where cloning an inline extent needs to copy the inline extent data into a page of the destination inode. When this happens, we end up starting a transaction while having a dirty page for the destination inode and while having the range locked in the destination's inode iotree too. Because when reserving metadata space for a transaction we may need to flush existing delalloc in case there is not enough free space, we have a mechanism in place to prevent a deadlock, which was introduced in commit 3d45f221ce627d ("btrfs: fix deadlock when cloning inline extent and low on free metadata space"). However when using qgroups, a transaction also reserves metadata qgroup space, which can also result in flushing delalloc in case there is not enough available space at the moment. When this happens we deadlock, since flushing delalloc requires locking the file range in the inode's iotree and the range was already locked at the very beginning of the clone operation, before attempting to start the transaction. When this issue happens, stack traces like the following are reported: [72747.556262] task:kworker/u81:9 state:D stack: 0 pid: 225 ppid: 2 flags:0x00004000 [72747.556268] Workqueue: writeback wb_workfn (flush-btrfs-1142) [72747.556271] Call Trace: [72747.556273] __schedule+0x296/0x760 [72747.556277] schedule+0x3c/0xa0 [72747.556279] io_schedule+0x12/0x40 [72747.556284] __lock_page+0x13c/0x280 [72747.556287] ? generic_file_readonly_mmap+0x70/0x70 [72747.556325] extent_write_cache_pages+0x22a/0x440 [btrfs] [72747.556331] ? __set_page_dirty_nobuffers+0xe7/0x160 [72747.556358] ? set_extent_buffer_dirty+0x5e/0x80 [btrfs] [72747.556362] ? update_group_capacity+0x25/0x210 [72747.556366] ? cpumask_next_and+0x1a/0x20 [72747.556391] extent_writepages+0x44/0xa0 [btrfs] [72747.556394] do_writepages+0x41/0xd0 [72747.556398] __writeback_single_inode+0x39/0x2a0 [72747.556403] writeback_sb_inodes+0x1ea/0x440 [72747.556407] __writeback_inodes_wb+0x5f/0xc0 [72747.556410] wb_writeback+0x235/0x2b0 [72747.556414] ? get_nr_inodes+0x35/0x50 [72747.556417] wb_workfn+0x354/0x490 [72747.556420] ? newidle_balance+0x2c5/0x3e0 [72747.556424] process_one_work+0x1aa/0x340 [72747.556426] worker_thread+0x30/0x390 [72747.556429] ? create_worker+0x1a0/0x1a0 [72747.556432] kthread+0x116/0x130 [72747.556435] ? kthread_park+0x80/0x80 [72747.556438] ret_from_fork+0x1f/0x30 [72747.566958] Workqueue: btrfs-flush_delalloc btrfs_work_helper [btrfs] [72747.566961] Call Trace: [72747.566964] __schedule+0x296/0x760 [72747.566968] ? finish_wait+0x80/0x80 [72747.566970] schedule+0x3c/0xa0 [72747.566995] wait_extent_bit.constprop.68+0x13b/0x1c0 [btrfs] [72747.566999] ? finish_wait+0x80/0x80 [72747.567024] lock_extent_bits+0x37/0x90 [btrfs] [72747.567047] btrfs_invalidatepage+0x299/0x2c0 [btrfs] [72747.567051] ? find_get_pages_range_tag+0x2cd/0x380 [72747.567076] __extent_writepage+0x203/0x320 [btrfs] [72747.567102] extent_write_cache_pages+0x2bb/0x440 [btrfs] [72747.567106] ? update_load_avg+0x7e/0x5f0 [72747.567109] ? enqueue_entity+0xf4/0x6f0 [72747.567134] extent_writepages+0x44/0xa0 [btrfs] [72747.567137] ? enqueue_task_fair+0x93/0x6f0 [72747.567140] do_writepages+0x41/0xd0 [72747.567144] __filemap_fdatawrite_range+0xc7/0x100 [72747.567167] btrfs_run_delalloc_work+0x17/0x40 [btrfs] [72747.567195] btrfs_work_helper+0xc2/0x300 [btrfs] [72747.567200] process_one_work+0x1aa/0x340 [72747.567202] worker_thread+0x30/0x390 [72747.567205] ? create_worker+0x1a0/0x1a0 [72747.567208] kthread+0x116/0x130 [72747.567211] ? kthread_park+0x80/0x80 [72747.567214] ret_from_fork+0x1f/0x30 [72747.569686] task:fsstress state:D stack: ---truncated---

A vulnerability was found in btrfs_alloc_tree_b in fs/btrfs/extent-tree.c in the Linux kernel due to an improper lock operation in btrfs. In this flaw, a user with a local privilege may cause a denial of service (DOS) due to a deadlock problem.

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: 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: 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: 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: 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.

A vulnerability was found due to missing lock for IOPOLL flaw in io_cqring_event_overflow() in io_uring.c in Linux Kernel. This flaw allows a local attacker with user privilege to trigger a Denial of Service threat.

In the Linux kernel before 4.16.4, a double-locking error in drivers/usb/dwc3/gadget.c may potentially cause a deadlock with f_hid.

In the Linux kernel, the following vulnerability has been resolved: usb: musb: Fix hardware lockup on first Rx endpoint request There is a possibility that a request's callback could be invoked from usb_ep_queue() (call trace below, supplemented with missing calls): req->complete from usb_gadget_giveback_request (drivers/usb/gadget/udc/core.c:999) usb_gadget_giveback_request from musb_g_giveback (drivers/usb/musb/musb_gadget.c:147) musb_g_giveback from rxstate (drivers/usb/musb/musb_gadget.c:784) rxstate from musb_ep_restart (drivers/usb/musb/musb_gadget.c:1169) musb_ep_restart from musb_ep_restart_resume_work (drivers/usb/musb/musb_gadget.c:1176) musb_ep_restart_resume_work from musb_queue_resume_work (drivers/usb/musb/musb_core.c:2279) musb_queue_resume_work from musb_gadget_queue (drivers/usb/musb/musb_gadget.c:1241) musb_gadget_queue from usb_ep_queue (drivers/usb/gadget/udc/core.c:300) According to the docstring of usb_ep_queue(), this should not happen: "Note that @req's ->complete() callback must never be called from within usb_ep_queue() as that can create deadlock situations." In fact, a hardware lockup might occur in the following sequence: 1. The gadget is initialized using musb_gadget_enable(). 2. Meanwhile, a packet arrives, and the RXPKTRDY flag is set, raising an interrupt. 3. If IRQs are enabled, the interrupt is handled, but musb_g_rx() finds an empty queue (next_request() returns NULL). The interrupt flag has already been cleared by the glue layer handler, but the RXPKTRDY flag remains set. 4. The first request is enqueued using usb_ep_queue(), leading to the call of req->complete(), as shown in the call trace above. 5. If the callback enables IRQs and another packet is waiting, step (3) repeats. The request queue is empty because usb_g_giveback() removes the request before invoking the callback. 6. The endpoint remains locked up, as the interrupt triggered by hardware setting the RXPKTRDY flag has been handled, but the flag itself remains set. For this scenario to occur, it is only necessary for IRQs to be enabled at some point during the complete callback. This happens with the USB Ethernet gadget, whose rx_complete() callback calls netif_rx(). If called in the task context, netif_rx() disables the bottom halves (BHs). When the BHs are re-enabled, IRQs are also enabled to allow soft IRQs to be processed. The gadget itself is initialized at module load (or at boot if built-in), but the first request is enqueued when the network interface is brought up, triggering rx_complete() in the task context via ioctl(). If a packet arrives while the interface is down, it can prevent the interface from receiving any further packets from the USB host. The situation is quite complicated with many parties involved. This particular issue can be resolved in several possible ways: 1. Ensure that callbacks never enable IRQs. This would be difficult to enforce, as discovering how netif_rx() interacts with interrupts was already quite challenging and u_ether is not the only function driver. Similar "bugs" could be hidden in other drivers as well. 2. Disable MUSB interrupts in musb_g_giveback() before calling the callback and re-enable them afterwars (by calling musb_{dis,en}able_interrupts(), for example). This would ensure that MUSB interrupts are not handled during the callback, even if IRQs are enabled. In fact, it would allow IRQs to be enabled when releasing the lock. However, this feels like an inelegant hack. 3. Modify the interrupt handler to clear the RXPKTRDY flag if the request queue is empty. While this approach also feels like a hack, it wastes CPU time by attempting to handle incoming packets when the software is not ready to process them. 4. Flush the Rx FIFO instead of calling rxstate() in musb_ep_restart(). This ensures that the hardware can receive packets when there is at least one request in the queue. Once I ---truncated---

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: Fix possible deadlocks This fixes possible deadlocks like the following caused by hci_cmd_sync_dequeue causing the destroy function to run: INFO: task kworker/u19:0:143 blocked for more than 120 seconds. Tainted: G W O 6.8.0-2024-03-19-intel-next-iLS-24ww14 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u19:0 state:D stack:0 pid:143 tgid:143 ppid:2 flags:0x00004000 Workqueue: hci0 hci_cmd_sync_work [bluetooth] Call Trace: <TASK> __schedule+0x374/0xaf0 schedule+0x3c/0xf0 schedule_preempt_disabled+0x1c/0x30 __mutex_lock.constprop.0+0x3ef/0x7a0 __mutex_lock_slowpath+0x13/0x20 mutex_lock+0x3c/0x50 mgmt_set_connectable_complete+0xa4/0x150 [bluetooth] ? kfree+0x211/0x2a0 hci_cmd_sync_dequeue+0xae/0x130 [bluetooth] ? __pfx_cmd_complete_rsp+0x10/0x10 [bluetooth] cmd_complete_rsp+0x26/0x80 [bluetooth] mgmt_pending_foreach+0x4d/0x70 [bluetooth] __mgmt_power_off+0x8d/0x180 [bluetooth] ? _raw_spin_unlock_irq+0x23/0x40 hci_dev_close_sync+0x445/0x5b0 [bluetooth] hci_set_powered_sync+0x149/0x250 [bluetooth] set_powered_sync+0x24/0x60 [bluetooth] hci_cmd_sync_work+0x90/0x150 [bluetooth] process_one_work+0x13e/0x300 worker_thread+0x2f7/0x420 ? __pfx_worker_thread+0x10/0x10 kthread+0x107/0x140 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3d/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK>

The ptrace_start function in kernel/ptrace.c in the Linux kernel 2.6.18 does not properly handle simultaneous execution of the do_coredump function, which allows local users to cause a denial of service (deadlock) via vectors involving the ptrace system call and a coredumping thread.

In the Linux kernel, the following vulnerability has been resolved: powerpc/qspinlock: Fix deadlock in MCS queue If an interrupt occurs in queued_spin_lock_slowpath() after we increment qnodesp->count and before node->lock is initialized, another CPU might see stale lock values in get_tail_qnode(). If the stale lock value happens to match the lock on that CPU, then we write to the "next" pointer of the wrong qnode. This causes a deadlock as the former CPU, once it becomes the head of the MCS queue, will spin indefinitely until it's "next" pointer is set by its successor in the queue. Running stress-ng on a 16 core (16EC/16VP) shared LPAR, results in occasional lockups similar to the following: $ stress-ng --all 128 --vm-bytes 80% --aggressive \ --maximize --oomable --verify --syslog \ --metrics --times --timeout 5m watchdog: CPU 15 Hard LOCKUP ...... NIP [c0000000000b78f4] queued_spin_lock_slowpath+0x1184/0x1490 LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90 Call Trace: 0xc000002cfffa3bf0 (unreliable) _raw_spin_lock+0x6c/0x90 raw_spin_rq_lock_nested.part.135+0x4c/0xd0 sched_ttwu_pending+0x60/0x1f0 __flush_smp_call_function_queue+0x1dc/0x670 smp_ipi_demux_relaxed+0xa4/0x100 xive_muxed_ipi_action+0x20/0x40 __handle_irq_event_percpu+0x80/0x240 handle_irq_event_percpu+0x2c/0x80 handle_percpu_irq+0x84/0xd0 generic_handle_irq+0x54/0x80 __do_irq+0xac/0x210 __do_IRQ+0x74/0xd0 0x0 do_IRQ+0x8c/0x170 hardware_interrupt_common_virt+0x29c/0x2a0 --- interrupt: 500 at queued_spin_lock_slowpath+0x4b8/0x1490 ...... NIP [c0000000000b6c28] queued_spin_lock_slowpath+0x4b8/0x1490 LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90 --- interrupt: 500 0xc0000029c1a41d00 (unreliable) _raw_spin_lock+0x6c/0x90 futex_wake+0x100/0x260 do_futex+0x21c/0x2a0 sys_futex+0x98/0x270 system_call_exception+0x14c/0x2f0 system_call_vectored_common+0x15c/0x2ec The following code flow illustrates how the deadlock occurs. For the sake of brevity, assume that both locks (A and B) are contended and we call the queued_spin_lock_slowpath() function. CPU0 CPU1 ---- ---- spin_lock_irqsave(A) | spin_unlock_irqrestore(A) | spin_lock(B) | | | ▼ | id = qnodesp->count++; | (Note that nodes[0].lock == A) | | | ▼ | Interrupt | (happens before "nodes[0].lock = B") | | | ▼ | spin_lock_irqsave(A) | | | ▼ | id = qnodesp->count++ | nodes[1].lock = A | | | ▼ | Tail of MCS queue | | spin_lock_irqsave(A) ▼ | Head of MCS queue ▼ | CPU0 is previous tail ▼ | Spin indefinitely ▼ (until "nodes[1].next != NULL") prev = get_tail_qnode(A, CPU0) | ▼ prev == &qnodes[CPU0].nodes[0] (as qnodes ---truncated---

In the Linux kernel, the following vulnerability has been resolved: pinmux: Use sequential access to access desc->pinmux data When two client of the same gpio call pinctrl_select_state() for the same functionality, we are seeing NULL pointer issue while accessing desc->mux_owner. Let's say two processes A, B executing in pin_request() for the same pin and process A updates the desc->mux_usecount but not yet updated the desc->mux_owner while process B see the desc->mux_usecount which got updated by A path and further executes strcmp and while accessing desc->mux_owner it crashes with NULL pointer. Serialize the access to mux related setting with a mutex lock. cpu0 (process A) cpu1(process B) pinctrl_select_state() { pinctrl_select_state() { pin_request() { pin_request() { ... .... } else { desc->mux_usecount++; desc->mux_usecount && strcmp(desc->mux_owner, owner)) { if (desc->mux_usecount > 1) return 0; desc->mux_owner = owner; } }

In the Linux kernel, the following vulnerability has been resolved: dma-debug: fix a possible deadlock on radix_lock radix_lock() shouldn't be held while holding dma_hash_entry[idx].lock otherwise, there's a possible deadlock scenario when dma debug API is called holding rq_lock(): CPU0 CPU1 CPU2 dma_free_attrs() check_unmap() add_dma_entry() __schedule() //out (A) rq_lock() get_hash_bucket() (A) dma_entry_hash check_sync() (A) radix_lock() (W) dma_entry_hash dma_entry_free() (W) radix_lock() // CPU2's one (W) rq_lock() CPU1 situation can happen when it extending radix tree and it tries to wake up kswapd via wake_all_kswapd(). CPU2 situation can happen while perf_event_task_sched_out() (i.e. dma sync operation is called while deleting perf_event using etm and etr tmc which are Arm Coresight hwtracing driver backends). To remove this possible situation, call dma_entry_free() after put_hash_bucket() in check_unmap().

In the Linux kernel, the following vulnerability has been resolved: RDMA/hns: Fix soft lockup under heavy CEQE load CEQEs are handled in interrupt handler currently. This may cause the CPU core staying in interrupt context too long and lead to soft lockup under heavy load. Handle CEQEs in BH workqueue and set an upper limit for the number of CEQE handled by a single call of work handler.

In the Linux kernel, the following vulnerability has been resolved: i2c: pnx: Fix potential deadlock warning from del_timer_sync() call in isr When del_timer_sync() is called in an interrupt context it throws a warning because of potential deadlock. The timer is used only to exit from wait_for_completion() after a timeout so replacing the call with wait_for_completion_timeout() allows to remove the problematic timer and its related functions altogether.

In the Linux kernel, the following vulnerability has been resolved: riscv: kexec: Avoid deadlock in kexec crash path If the kexec crash code is called in the interrupt context, the machine_kexec_mask_interrupts() function will trigger a deadlock while trying to acquire the irqdesc spinlock and then deactivate irqchip in irq_set_irqchip_state() function. Unlike arm64, riscv only requires irq_eoi handler to complete EOI and keeping irq_set_irqchip_state() will only leave this possible deadlock without any use. So we simply remove it.

In the Linux kernel, the following vulnerability has been resolved: block: fix deadlock between sd_remove & sd_release Our test report the following hung task: [ 2538.459400] INFO: task "kworker/0:0":7 blocked for more than 188 seconds. [ 2538.459427] Call trace: [ 2538.459430] __switch_to+0x174/0x338 [ 2538.459436] __schedule+0x628/0x9c4 [ 2538.459442] schedule+0x7c/0xe8 [ 2538.459447] schedule_preempt_disabled+0x24/0x40 [ 2538.459453] __mutex_lock+0x3ec/0xf04 [ 2538.459456] __mutex_lock_slowpath+0x14/0x24 [ 2538.459459] mutex_lock+0x30/0xd8 [ 2538.459462] del_gendisk+0xdc/0x350 [ 2538.459466] sd_remove+0x30/0x60 [ 2538.459470] device_release_driver_internal+0x1c4/0x2c4 [ 2538.459474] device_release_driver+0x18/0x28 [ 2538.459478] bus_remove_device+0x15c/0x174 [ 2538.459483] device_del+0x1d0/0x358 [ 2538.459488] __scsi_remove_device+0xa8/0x198 [ 2538.459493] scsi_forget_host+0x50/0x70 [ 2538.459497] scsi_remove_host+0x80/0x180 [ 2538.459502] usb_stor_disconnect+0x68/0xf4 [ 2538.459506] usb_unbind_interface+0xd4/0x280 [ 2538.459510] device_release_driver_internal+0x1c4/0x2c4 [ 2538.459514] device_release_driver+0x18/0x28 [ 2538.459518] bus_remove_device+0x15c/0x174 [ 2538.459523] device_del+0x1d0/0x358 [ 2538.459528] usb_disable_device+0x84/0x194 [ 2538.459532] usb_disconnect+0xec/0x300 [ 2538.459537] hub_event+0xb80/0x1870 [ 2538.459541] process_scheduled_works+0x248/0x4dc [ 2538.459545] worker_thread+0x244/0x334 [ 2538.459549] kthread+0x114/0x1bc [ 2538.461001] INFO: task "fsck.":15415 blocked for more than 188 seconds. [ 2538.461014] Call trace: [ 2538.461016] __switch_to+0x174/0x338 [ 2538.461021] __schedule+0x628/0x9c4 [ 2538.461025] schedule+0x7c/0xe8 [ 2538.461030] blk_queue_enter+0xc4/0x160 [ 2538.461034] blk_mq_alloc_request+0x120/0x1d4 [ 2538.461037] scsi_execute_cmd+0x7c/0x23c [ 2538.461040] ioctl_internal_command+0x5c/0x164 [ 2538.461046] scsi_set_medium_removal+0x5c/0xb0 [ 2538.461051] sd_release+0x50/0x94 [ 2538.461054] blkdev_put+0x190/0x28c [ 2538.461058] blkdev_release+0x28/0x40 [ 2538.461063] __fput+0xf8/0x2a8 [ 2538.461066] __fput_sync+0x28/0x5c [ 2538.461070] __arm64_sys_close+0x84/0xe8 [ 2538.461073] invoke_syscall+0x58/0x114 [ 2538.461078] el0_svc_common+0xac/0xe0 [ 2538.461082] do_el0_svc+0x1c/0x28 [ 2538.461087] el0_svc+0x38/0x68 [ 2538.461090] el0t_64_sync_handler+0x68/0xbc [ 2538.461093] el0t_64_sync+0x1a8/0x1ac T1: T2: sd_remove del_gendisk __blk_mark_disk_dead blk_freeze_queue_start ++q->mq_freeze_depth bdev_release mutex_lock(&disk->open_mutex) sd_release scsi_execute_cmd blk_queue_enter wait_event(!q->mq_freeze_depth) mutex_lock(&disk->open_mutex) SCSI does not set GD_OWNS_QUEUE, so QUEUE_FLAG_DYING is not set in this scenario. This is a classic ABBA deadlock. To fix the deadlock, make sure we don't try to acquire disk->open_mutex after freezing the queue.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Fix missing lock on sync reset reload On sync reset reload work, when remote host updates devlink on reload actions performed on that host, it misses taking devlink lock before calling devlink_remote_reload_actions_performed() which results in triggering lock assert like the following: WARNING: CPU: 4 PID: 1164 at net/devlink/core.c:261 devl_assert_locked+0x3e/0x50 … CPU: 4 PID: 1164 Comm: kworker/u96:6 Tainted: G S W 6.10.0-rc2+ #116 Hardware name: Supermicro SYS-2028TP-DECTR/X10DRT-PT, BIOS 2.0 12/18/2015 Workqueue: mlx5_fw_reset_events mlx5_sync_reset_reload_work [mlx5_core] RIP: 0010:devl_assert_locked+0x3e/0x50 … Call Trace: <TASK> ? __warn+0xa4/0x210 ? devl_assert_locked+0x3e/0x50 ? report_bug+0x160/0x280 ? handle_bug+0x3f/0x80 ? exc_invalid_op+0x17/0x40 ? asm_exc_invalid_op+0x1a/0x20 ? devl_assert_locked+0x3e/0x50 devlink_notify+0x88/0x2b0 ? mlx5_attach_device+0x20c/0x230 [mlx5_core] ? __pfx_devlink_notify+0x10/0x10 ? process_one_work+0x4b6/0xbb0 process_one_work+0x4b6/0xbb0 […]

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7921s: fix potential hung tasks during chip recovery During chip recovery (e.g. chip reset), there is a possible situation that kernel worker reset_work is holding the lock and waiting for kernel thread stat_worker to be parked, while stat_worker is waiting for the release of the same lock. It causes a deadlock resulting in the dumping of hung tasks messages and possible rebooting of the device. This patch prevents the execution of stat_worker during the chip recovery.

In the Linux kernel, the following vulnerability has been resolved: io_uring: fix possible deadlock in io_register_iowq_max_workers() The io_register_iowq_max_workers() function calls io_put_sq_data(), which acquires the sqd->lock without releasing the uring_lock. Similar to the commit 009ad9f0c6ee ("io_uring: drop ctx->uring_lock before acquiring sqd->lock"), this can lead to a potential deadlock situation. To resolve this issue, the uring_lock is released before calling io_put_sq_data(), and then it is re-acquired after the function call. This change ensures that the locks are acquired in the correct order, preventing the possibility of a deadlock.

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: drop_monitor: replace spin_lock by raw_spin_lock trace_drop_common() is called with preemption disabled, and it acquires a spin_lock. This is problematic for RT kernels because spin_locks are sleeping locks in this configuration, which causes the following splat: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 449, name: rcuc/47 preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 2 5 locks held by rcuc/47/449: #0: ff1100086ec30a60 ((softirq_ctrl.lock)){+.+.}-{2:2}, at: __local_bh_disable_ip+0x105/0x210 #1: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0xbf/0x130 #2: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: __local_bh_disable_ip+0x11c/0x210 #3: ffffffffb394a160 (rcu_callback){....}-{0:0}, at: rcu_do_batch+0x360/0xc70 #4: ff1100086ee07520 (&data->lock){+.+.}-{2:2}, at: trace_drop_common.constprop.0+0xb5/0x290 irq event stamp: 139909 hardirqs last enabled at (139908): [<ffffffffb1df2b33>] _raw_spin_unlock_irqrestore+0x63/0x80 hardirqs last disabled at (139909): [<ffffffffb19bd03d>] trace_drop_common.constprop.0+0x26d/0x290 softirqs last enabled at (139892): [<ffffffffb07a1083>] __local_bh_enable_ip+0x103/0x170 softirqs last disabled at (139898): [<ffffffffb0909b33>] rcu_cpu_kthread+0x93/0x1f0 Preemption disabled at: [<ffffffffb1de786b>] rt_mutex_slowunlock+0xab/0x2e0 CPU: 47 PID: 449 Comm: rcuc/47 Not tainted 6.9.0-rc2-rt1+ #7 Hardware name: Dell Inc. PowerEdge R650/0Y2G81, BIOS 1.6.5 04/15/2022 Call Trace: <TASK> dump_stack_lvl+0x8c/0xd0 dump_stack+0x14/0x20 __might_resched+0x21e/0x2f0 rt_spin_lock+0x5e/0x130 ? trace_drop_common.constprop.0+0xb5/0x290 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_drop_common.constprop.0+0xb5/0x290 ? preempt_count_sub+0x1c/0xd0 ? _raw_spin_unlock_irqrestore+0x4a/0x80 ? __pfx_trace_drop_common.constprop.0+0x10/0x10 ? rt_mutex_slowunlock+0x26a/0x2e0 ? skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_rt_mutex_slowunlock+0x10/0x10 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_kfree_skb_hit+0x15/0x20 trace_kfree_skb+0xe9/0x150 kfree_skb_reason+0x7b/0x110 skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_skb_queue_purge_reason.part.0+0x10/0x10 ? mark_lock.part.0+0x8a/0x520 ... trace_drop_common() also disables interrupts, but this is a minor issue because we could easily replace it with a local_lock. Replace the spin_lock with raw_spin_lock to avoid sleeping in atomic context.

In the Linux kernel, the following vulnerability has been resolved: media: uvcvideo: Fix deadlock during uvc_probe If uvc_probe() fails, it can end up calling uvc_status_unregister() before uvc_status_init() is called. Fix this by checking if dev->status is NULL or not in uvc_status_unregister().

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix deadlock when freeing cgroup storage The following commit bc235cdb423a ("bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]") first introduced deadlock prevention for fentry/fexit programs attaching on bpf_task_storage helpers. That commit also employed the logic in map free path in its v6 version. Later bpf_cgrp_storage was first introduced in c4bcfb38a95e ("bpf: Implement cgroup storage available to non-cgroup-attached bpf progs") which faces the same issue as bpf_task_storage, instead of its busy counter, NULL was passed to bpf_local_storage_map_free() which opened a window to cause deadlock: <TASK> (acquiring local_storage->lock) _raw_spin_lock_irqsave+0x3d/0x50 bpf_local_storage_update+0xd1/0x460 bpf_cgrp_storage_get+0x109/0x130 bpf_prog_a4d4a370ba857314_cgrp_ptr+0x139/0x170 ? __bpf_prog_enter_recur+0x16/0x80 bpf_trampoline_6442485186+0x43/0xa4 cgroup_storage_ptr+0x9/0x20 (holding local_storage->lock) bpf_selem_unlink_storage_nolock.constprop.0+0x135/0x160 bpf_selem_unlink_storage+0x6f/0x110 bpf_local_storage_map_free+0xa2/0x110 bpf_map_free_deferred+0x5b/0x90 process_one_work+0x17c/0x390 worker_thread+0x251/0x360 kthread+0xd2/0x100 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1a/0x30 </TASK> Progs: - A: SEC("fentry/cgroup_storage_ptr") - cgid (BPF_MAP_TYPE_HASH) Record the id of the cgroup the current task belonging to in this hash map, using the address of the cgroup as the map key. - cgrpa (BPF_MAP_TYPE_CGRP_STORAGE) If current task is a kworker, lookup the above hash map using function parameter @owner as the key to get its corresponding cgroup id which is then used to get a trusted pointer to the cgroup through bpf_cgroup_from_id(). This trusted pointer can then be passed to bpf_cgrp_storage_get() to finally trigger the deadlock issue. - B: SEC("tp_btf/sys_enter") - cgrpb (BPF_MAP_TYPE_CGRP_STORAGE) The only purpose of this prog is to fill Prog A's hash map by calling bpf_cgrp_storage_get() for as many userspace tasks as possible. Steps to reproduce: - Run A; - while (true) { Run B; Destroy B; } Fix this issue by passing its busy counter to the free procedure so it can be properly incremented before storage/smap locking.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: iso: Fix circular lock in iso_conn_big_sync This fixes the circular locking dependency warning below, by reworking iso_sock_recvmsg, to ensure that the socket lock is always released before calling a function that locks hdev. [ 561.670344] ====================================================== [ 561.670346] WARNING: possible circular locking dependency detected [ 561.670349] 6.12.0-rc6+ #26 Not tainted [ 561.670351] ------------------------------------------------------ [ 561.670353] iso-tester/3289 is trying to acquire lock: [ 561.670355] ffff88811f600078 (&hdev->lock){+.+.}-{3:3}, at: iso_conn_big_sync+0x73/0x260 [bluetooth] [ 561.670405] but task is already holding lock: [ 561.670407] ffff88815af58258 (sk_lock-AF_BLUETOOTH){+.+.}-{0:0}, at: iso_sock_recvmsg+0xbf/0x500 [bluetooth] [ 561.670450] which lock already depends on the new lock. [ 561.670452] the existing dependency chain (in reverse order) is: [ 561.670453] -> #2 (sk_lock-AF_BLUETOOTH){+.+.}-{0:0}: [ 561.670458] lock_acquire+0x7c/0xc0 [ 561.670463] lock_sock_nested+0x3b/0xf0 [ 561.670467] bt_accept_dequeue+0x1a5/0x4d0 [bluetooth] [ 561.670510] iso_sock_accept+0x271/0x830 [bluetooth] [ 561.670547] do_accept+0x3dd/0x610 [ 561.670550] __sys_accept4+0xd8/0x170 [ 561.670553] __x64_sys_accept+0x74/0xc0 [ 561.670556] x64_sys_call+0x17d6/0x25f0 [ 561.670559] do_syscall_64+0x87/0x150 [ 561.670563] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 561.670567] -> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}: [ 561.670571] lock_acquire+0x7c/0xc0 [ 561.670574] lock_sock_nested+0x3b/0xf0 [ 561.670577] iso_sock_listen+0x2de/0xf30 [bluetooth] [ 561.670617] __sys_listen_socket+0xef/0x130 [ 561.670620] __x64_sys_listen+0xe1/0x190 [ 561.670623] x64_sys_call+0x2517/0x25f0 [ 561.670626] do_syscall_64+0x87/0x150 [ 561.670629] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 561.670632] -> #0 (&hdev->lock){+.+.}-{3:3}: [ 561.670636] __lock_acquire+0x32ad/0x6ab0 [ 561.670639] lock_acquire.part.0+0x118/0x360 [ 561.670642] lock_acquire+0x7c/0xc0 [ 561.670644] __mutex_lock+0x18d/0x12f0 [ 561.670647] mutex_lock_nested+0x1b/0x30 [ 561.670651] iso_conn_big_sync+0x73/0x260 [bluetooth] [ 561.670687] iso_sock_recvmsg+0x3e9/0x500 [bluetooth] [ 561.670722] sock_recvmsg+0x1d5/0x240 [ 561.670725] sock_read_iter+0x27d/0x470 [ 561.670727] vfs_read+0x9a0/0xd30 [ 561.670731] ksys_read+0x1a8/0x250 [ 561.670733] __x64_sys_read+0x72/0xc0 [ 561.670736] x64_sys_call+0x1b12/0x25f0 [ 561.670738] do_syscall_64+0x87/0x150 [ 561.670741] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 561.670744] other info that might help us debug this: [ 561.670745] Chain exists of: &hdev->lock --> sk_lock-AF_BLUETOOTH-BTPROTO_ISO --> sk_lock-AF_BLUETOOTH [ 561.670751] Possible unsafe locking scenario: [ 561.670753] CPU0 CPU1 [ 561.670754] ---- ---- [ 561.670756] lock(sk_lock-AF_BLUETOOTH); [ 561.670758] lock(sk_lock AF_BLUETOOTH-BTPROTO_ISO); [ 561.670761] lock(sk_lock-AF_BLUETOOTH); [ 561.670764] lock(&hdev->lock); [ 561.670767] *** DEADLOCK ***

In the Linux kernel, the following vulnerability has been resolved: btrfs: don't take dev_replace rwsem on task already holding it Running fstests btrfs/011 with MKFS_OPTIONS="-O rst" to force the usage of the RAID stripe-tree, we get the following splat from lockdep: BTRFS info (device sdd): dev_replace from /dev/sdd (devid 1) to /dev/sdb started ============================================ WARNING: possible recursive locking detected 6.11.0-rc3-btrfs-for-next #599 Not tainted -------------------------------------------- btrfs/2326 is trying to acquire lock: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250 but task is already holding lock: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&fs_info->dev_replace.rwsem); lock(&fs_info->dev_replace.rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by btrfs/2326: #0: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250 stack backtrace: CPU: 1 UID: 0 PID: 2326 Comm: btrfs Not tainted 6.11.0-rc3-btrfs-for-next #599 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0x5b/0x80 __lock_acquire+0x2798/0x69d0 ? __pfx___lock_acquire+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x19d/0x4a0 ? btrfs_map_block+0x39f/0x2250 ? __pfx_lock_acquire+0x10/0x10 ? find_held_lock+0x2d/0x110 ? lock_is_held_type+0x8f/0x100 down_read+0x8e/0x440 ? btrfs_map_block+0x39f/0x2250 ? __pfx_down_read+0x10/0x10 ? do_raw_read_unlock+0x44/0x70 ? _raw_read_unlock+0x23/0x40 btrfs_map_block+0x39f/0x2250 ? btrfs_dev_replace_by_ioctl+0xd69/0x1d00 ? btrfs_bio_counter_inc_blocked+0xd9/0x2e0 ? __kasan_slab_alloc+0x6e/0x70 ? __pfx_btrfs_map_block+0x10/0x10 ? __pfx_btrfs_bio_counter_inc_blocked+0x10/0x10 ? kmem_cache_alloc_noprof+0x1f2/0x300 ? mempool_alloc_noprof+0xed/0x2b0 btrfs_submit_chunk+0x28d/0x17e0 ? __pfx_btrfs_submit_chunk+0x10/0x10 ? bvec_alloc+0xd7/0x1b0 ? bio_add_folio+0x171/0x270 ? __pfx_bio_add_folio+0x10/0x10 ? __kasan_check_read+0x20/0x20 btrfs_submit_bio+0x37/0x80 read_extent_buffer_pages+0x3df/0x6c0 btrfs_read_extent_buffer+0x13e/0x5f0 read_tree_block+0x81/0xe0 read_block_for_search+0x4bd/0x7a0 ? __pfx_read_block_for_search+0x10/0x10 btrfs_search_slot+0x78d/0x2720 ? __pfx_btrfs_search_slot+0x10/0x10 ? lock_is_held_type+0x8f/0x100 ? kasan_save_track+0x14/0x30 ? __kasan_slab_alloc+0x6e/0x70 ? kmem_cache_alloc_noprof+0x1f2/0x300 btrfs_get_raid_extent_offset+0x181/0x820 ? __pfx_lock_acquire+0x10/0x10 ? __pfx_btrfs_get_raid_extent_offset+0x10/0x10 ? down_read+0x194/0x440 ? __pfx_down_read+0x10/0x10 ? do_raw_read_unlock+0x44/0x70 ? _raw_read_unlock+0x23/0x40 btrfs_map_block+0x5b5/0x2250 ? __pfx_btrfs_map_block+0x10/0x10 scrub_submit_initial_read+0x8fe/0x11b0 ? __pfx_scrub_submit_initial_read+0x10/0x10 submit_initial_group_read+0x161/0x3a0 ? lock_release+0x20e/0x710 ? __pfx_submit_initial_group_read+0x10/0x10 ? __pfx_lock_release+0x10/0x10 scrub_simple_mirror.isra.0+0x3eb/0x580 scrub_stripe+0xe4d/0x1440 ? lock_release+0x20e/0x710 ? __pfx_scrub_stripe+0x10/0x10 ? __pfx_lock_release+0x10/0x10 ? do_raw_read_unlock+0x44/0x70 ? _raw_read_unlock+0x23/0x40 scrub_chunk+0x257/0x4a0 scrub_enumerate_chunks+0x64c/0xf70 ? __mutex_unlock_slowpath+0x147/0x5f0 ? __pfx_scrub_enumerate_chunks+0x10/0x10 ? bit_wait_timeout+0xb0/0x170 ? __up_read+0x189/0x700 ? scrub_workers_get+0x231/0x300 ? up_write+0x490/0x4f0 btrfs_scrub_dev+0x52e/0xcd0 ? create_pending_snapshots+0x230/0x250 ? __pfx_btrfs_scrub_dev+0x10/0x10 btrfs_dev_replace_by_ioctl+0xd69/0x1d00 ? lock_acquire+0x19d/0x4a0 ? __pfx_btrfs_dev_replace_by_ioctl+0x10/0x10 ? ---truncated---

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Reload only IB representors upon lag disable/enable On lag disable, the bond IB device along with all of its representors are destroyed, and then the slaves' representors get reloaded. In case the slave IB representor load fails, the eswitch error flow unloads all representors, including ethernet representors, where the netdevs get detached and removed from lag bond. Such flow is inaccurate as the lag driver is not responsible for loading/unloading ethernet representors. Furthermore, the flow described above begins by holding lag lock to prevent bond changes during disable flow. However, when reaching the ethernet representors detachment from lag, the lag lock is required again, triggering the following deadlock: Call trace: __switch_to+0xf4/0x148 __schedule+0x2c8/0x7d0 schedule+0x50/0xe0 schedule_preempt_disabled+0x18/0x28 __mutex_lock.isra.13+0x2b8/0x570 __mutex_lock_slowpath+0x1c/0x28 mutex_lock+0x4c/0x68 mlx5_lag_remove_netdev+0x3c/0x1a0 [mlx5_core] mlx5e_uplink_rep_disable+0x70/0xa0 [mlx5_core] mlx5e_detach_netdev+0x6c/0xb0 [mlx5_core] mlx5e_netdev_change_profile+0x44/0x138 [mlx5_core] mlx5e_netdev_attach_nic_profile+0x28/0x38 [mlx5_core] mlx5e_vport_rep_unload+0x184/0x1b8 [mlx5_core] mlx5_esw_offloads_rep_load+0xd8/0xe0 [mlx5_core] mlx5_eswitch_reload_reps+0x74/0xd0 [mlx5_core] mlx5_disable_lag+0x130/0x138 [mlx5_core] mlx5_lag_disable_change+0x6c/0x70 [mlx5_core] // hold ldev->lock mlx5_devlink_eswitch_mode_set+0xc0/0x410 [mlx5_core] devlink_nl_cmd_eswitch_set_doit+0xdc/0x180 genl_family_rcv_msg_doit.isra.17+0xe8/0x138 genl_rcv_msg+0xe4/0x220 netlink_rcv_skb+0x44/0x108 genl_rcv+0x40/0x58 netlink_unicast+0x198/0x268 netlink_sendmsg+0x1d4/0x418 sock_sendmsg+0x54/0x60 __sys_sendto+0xf4/0x120 __arm64_sys_sendto+0x30/0x40 el0_svc_common+0x8c/0x120 do_el0_svc+0x30/0xa0 el0_svc+0x20/0x30 el0_sync_handler+0x90/0xb8 el0_sync+0x160/0x180 Thus, upon lag enable/disable, load and unload only the IB representors of the slaves preventing the deadlock mentioned above. While at it, refactor the mlx5_esw_offloads_rep_load() function to have a static helper method for its internal logic, in symmetry with the representor unload design.

In the Linux kernel, the following vulnerability has been resolved: HID: i2c-hid: remove I2C_HID_READ_PENDING flag to prevent lock-up The flag I2C_HID_READ_PENDING is used to serialize I2C operations. However, this is not necessary, because I2C core already has its own locking for that. More importantly, this flag can cause a lock-up: if the flag is set in i2c_hid_xfer() and an interrupt happens, the interrupt handler (i2c_hid_irq) will check this flag and return immediately without doing anything, then the interrupt handler will be invoked again in an infinite loop. Since interrupt handler is an RT task, it takes over the CPU and the flag-clearing task never gets scheduled, thus we have a lock-up. Delete this unnecessary flag.

In the Linux kernel, the following vulnerability has been resolved: block: Prevent potential deadlocks in zone write plug error recovery Zone write plugging for handling writes to zones of a zoned block device always execute a zone report whenever a write BIO to a zone fails. The intent of this is to ensure that the tracking of a zone write pointer is always correct to ensure that the alignment to a zone write pointer of write BIOs can be checked on submission and that we can always correctly emulate zone append operations using regular write BIOs. However, this error recovery scheme introduces a potential deadlock if a device queue freeze is initiated while BIOs are still plugged in a zone write plug and one of these write operation fails. In such case, the disk zone write plug error recovery work is scheduled and executes a report zone. This in turn can result in a request allocation in the underlying driver to issue the report zones command to the device. But with the device queue freeze already started, this allocation will block, preventing the report zone execution and the continuation of the processing of the plugged BIOs. As plugged BIOs hold a queue usage reference, the queue freeze itself will never complete, resulting in a deadlock. Avoid this problem by completely removing from the zone write plugging code the use of report zones operations after a failed write operation, instead relying on the device user to either execute a report zones, reset the zone, finish the zone, or give up writing to the device (which is a fairly common pattern for file systems which degrade to read-only after write failures). This is not an unreasonnable requirement as all well-behaved applications, FSes and device mapper already use report zones to recover from write errors whenever possible by comparing the current position of a zone write pointer with what their assumption about the position is. The changes to remove the automatic error recovery are as follows: - Completely remove the error recovery work and its associated resources (zone write plug list head, disk error list, and disk zone_wplugs_work work struct). This also removes the functions disk_zone_wplug_set_error() and disk_zone_wplug_clear_error(). - Change the BLK_ZONE_WPLUG_ERROR zone write plug flag into BLK_ZONE_WPLUG_NEED_WP_UPDATE. This new flag is set for a zone write plug whenever a write opration targetting the zone of the zone write plug fails. This flag indicates that the zone write pointer offset is not reliable and that it must be updated when the next report zone, reset zone, finish zone or disk revalidation is executed. - Modify blk_zone_write_plug_bio_endio() to set the BLK_ZONE_WPLUG_NEED_WP_UPDATE flag for the target zone of a failed write BIO. - Modify the function disk_zone_wplug_set_wp_offset() to clear this new flag, thus implementing recovery of a correct write pointer offset with the reset (all) zone and finish zone operations. - Modify blkdev_report_zones() to always use the disk_report_zones_cb() callback so that disk_zone_wplug_sync_wp_offset() can be called for any zone marked with the BLK_ZONE_WPLUG_NEED_WP_UPDATE flag. This implements recovery of a correct write pointer offset for zone write plugs marked with BLK_ZONE_WPLUG_NEED_WP_UPDATE and within the range of the report zones operation executed by the user. - Modify blk_revalidate_seq_zone() to call disk_zone_wplug_sync_wp_offset() for all sequential write required zones when a zoned block device is revalidated, thus always resolving any inconsistency between the write pointer offset of zone write plugs and the actual write pointer position of sequential zones.

In the Linux kernel, the following vulnerability has been resolved: mptcp: init: protect sched with rcu_read_lock Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT creates this splat when an MPTCP socket is created: ============================= WARNING: suspicious RCU usage 6.12.0-rc2+ #11 Not tainted ----------------------------- net/mptcp/sched.c:44 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by mptcp_connect/176. stack backtrace: CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ #11 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:123) lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7)) mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1)) ? sock_init_data_uid (arch/x86/include/asm/atomic.h:28) inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386) ? __sock_create (include/linux/rcupdate.h:347 (discriminator 1)) __sock_create (net/socket.c:1576) __sys_socket (net/socket.c:1671) ? __pfx___sys_socket (net/socket.c:1712) ? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1)) __x64_sys_socket (net/socket.c:1728) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) That's because when the socket is initialised, rcu_read_lock() is not used despite the explicit comment written above the declaration of mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the warning.

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Drop VM dma-resv lock on xe_sync_in_fence_get failure in exec IOCTL Upon failure all locks need to be dropped before returning to the user. (cherry picked from commit 7d1a4258e602ffdce529f56686925034c1b3b095)

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential deadlock with newly created symlinks Syzbot reported that page_symlink(), called by nilfs_symlink(), triggers memory reclamation involving the filesystem layer, which can result in circular lock dependencies among the reader/writer semaphore nilfs->ns_segctor_sem, s_writers percpu_rwsem (intwrite) and the fs_reclaim pseudo lock. This is because after commit 21fc61c73c39 ("don't put symlink bodies in pagecache into highmem"), the gfp flags of the page cache for symbolic links are overwritten to GFP_KERNEL via inode_nohighmem(). This is not a problem for symlinks read from the backing device, because the __GFP_FS flag is dropped after inode_nohighmem() is called. However, when a new symlink is created with nilfs_symlink(), the gfp flags remain overwritten to GFP_KERNEL. Then, memory allocation called from page_symlink() etc. triggers memory reclamation including the FS layer, which may call nilfs_evict_inode() or nilfs_dirty_inode(). And these can cause a deadlock if they are called while nilfs->ns_segctor_sem is held: Fix this issue by dropping the __GFP_FS flag from the page cache GFP flags of newly created symlinks in the same way that nilfs_new_inode() and __nilfs_read_inode() do, as a workaround until we adopt nofs allocation scope consistently or improve the locking constraints.

In the Linux kernel, the following vulnerability has been resolved: nouveau: offload fence uevents work to workqueue This should break the deadlock between the fctx lock and the irq lock. This offloads the processing off the work from the irq into a workqueue.

In the Linux kernel, the following vulnerability has been resolved: PCI/ASPM: Fix deadlock when enabling ASPM A last minute revert in 6.7-final introduced a potential deadlock when enabling ASPM during probe of Qualcomm PCIe controllers as reported by lockdep: ============================================ WARNING: possible recursive locking detected 6.7.0 #40 Not tainted -------------------------------------------- kworker/u16:5/90 is trying to acquire lock: ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pcie_aspm_pm_state_change+0x58/0xdc but task is already holding lock: ffffacfa78ced000 (pci_bus_sem){++++}-{3:3}, at: pci_walk_bus+0x34/0xbc other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(pci_bus_sem); lock(pci_bus_sem); *** DEADLOCK *** Call trace: print_deadlock_bug+0x25c/0x348 __lock_acquire+0x10a4/0x2064 lock_acquire+0x1e8/0x318 down_read+0x60/0x184 pcie_aspm_pm_state_change+0x58/0xdc pci_set_full_power_state+0xa8/0x114 pci_set_power_state+0xc4/0x120 qcom_pcie_enable_aspm+0x1c/0x3c [pcie_qcom] pci_walk_bus+0x64/0xbc qcom_pcie_host_post_init_2_7_0+0x28/0x34 [pcie_qcom] The deadlock can easily be reproduced on machines like the Lenovo ThinkPad X13s by adding a delay to increase the race window during asynchronous probe where another thread can take a write lock. Add a new pci_set_power_state_locked() and associated helper functions that can be called with the PCI bus semaphore held to avoid taking the read lock twice.

In the Linux kernel, the following vulnerability has been resolved: block: fix deadlock between bd_link_disk_holder and partition scan 'open_mutex' of gendisk is used to protect open/close block devices. But in bd_link_disk_holder(), it is used to protect the creation of symlink between holding disk and slave bdev, which introduces some issues. When bd_link_disk_holder() is called, the driver is usually in the process of initialization/modification and may suspend submitting io. At this time, any io hold 'open_mutex', such as scanning partitions, can cause deadlocks. For example, in raid: T1 T2 bdev_open_by_dev lock open_mutex [1] ... efi_partition ... md_submit_bio md_ioctl mddev_syspend -> suspend all io md_add_new_disk bind_rdev_to_array bd_link_disk_holder try lock open_mutex [2] md_handle_request -> wait mddev_resume T1 scan partition, T2 add a new device to raid. T1 waits for T2 to resume mddev, but T2 waits for open_mutex held by T1. Deadlock occurs. Fix it by introducing a local mutex 'blk_holder_mutex' to replace 'open_mutex'.

In the Linux kernel, the following vulnerability has been resolved: inet: read sk->sk_family once in inet_recv_error() inet_recv_error() is called without holding the socket lock. IPv6 socket could mutate to IPv4 with IPV6_ADDRFORM socket option and trigger a KCSAN warning.

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_mirred: use the backlog for mirred ingress The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress") hangs our testing VMs every 10 or so runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by lockdep. The problem as previously described by Davide (see Link) is that if we reverse flow of traffic with the redirect (egress -> ingress) we may reach the same socket which generated the packet. And we may still be holding its socket lock. The common solution to such deadlocks is to put the packet in the Rx backlog, rather than run the Rx path inline. Do that for all egress -> ingress reversals, not just once we started to nest mirred calls. In the past there was a concern that the backlog indirection will lead to loss of error reporting / less accurate stats. But the current workaround does not seem to address the issue.

In the Linux kernel, the following vulnerability has been resolved: net/sched: Fix mirred deadlock on device recursion When the mirred action is used on a classful egress qdisc and a packet is mirrored or redirected to self we hit a qdisc lock deadlock. See trace below. [..... other info removed for brevity....] [ 82.890906] [ 82.890906] ============================================ [ 82.890906] WARNING: possible recursive locking detected [ 82.890906] 6.8.0-05205-g77fadd89fe2d-dirty #213 Tainted: G W [ 82.890906] -------------------------------------------- [ 82.890906] ping/418 is trying to acquire lock: [ 82.890906] ffff888006994110 (&sch->q.lock){+.-.}-{3:3}, at: __dev_queue_xmit+0x1778/0x3550 [ 82.890906] [ 82.890906] but task is already holding lock: [ 82.890906] ffff888006994110 (&sch->q.lock){+.-.}-{3:3}, at: __dev_queue_xmit+0x1778/0x3550 [ 82.890906] [ 82.890906] other info that might help us debug this: [ 82.890906] Possible unsafe locking scenario: [ 82.890906] [ 82.890906] CPU0 [ 82.890906] ---- [ 82.890906] lock(&sch->q.lock); [ 82.890906] lock(&sch->q.lock); [ 82.890906] [ 82.890906] *** DEADLOCK *** [ 82.890906] [..... other info removed for brevity....] Example setup (eth0->eth0) to recreate tc qdisc add dev eth0 root handle 1: htb default 30 tc filter add dev eth0 handle 1: protocol ip prio 2 matchall \ action mirred egress redirect dev eth0 Another example(eth0->eth1->eth0) to recreate tc qdisc add dev eth0 root handle 1: htb default 30 tc filter add dev eth0 handle 1: protocol ip prio 2 matchall \ action mirred egress redirect dev eth1 tc qdisc add dev eth1 root handle 1: htb default 30 tc filter add dev eth1 handle 1: protocol ip prio 2 matchall \ action mirred egress redirect dev eth0 We fix this by adding an owner field (CPU id) to struct Qdisc set after root qdisc is entered. When the softirq enters it a second time, if the qdisc owner is the same CPU, the packet is dropped to break the loop.

In the Linux kernel, the following vulnerability has been resolved: drm/xe/guc_submit: add missing locking in wedged_fini Any non-wedged queue can have a zero refcount here and can be running concurrently with an async queue destroy, therefore dereferencing the queue ptr to check wedge status after the lookup can trigger UAF if queue is not wedged. Fix this by keeping the submission_state lock held around the check to postpone the free and make the check safe, before dropping again around the put() to avoid the deadlock. (cherry picked from commit d28af0b6b9580b9f90c265a7da0315b0ad20bbfd)

In the Linux kernel, the following vulnerability has been resolved: RDMA/hns: Fix spin_unlock_irqrestore() called with IRQs enabled Fix missuse of spin_lock_irq()/spin_unlock_irq() when spin_lock_irqsave()/spin_lock_irqrestore() was hold. This was discovered through the lock debugging, and the corresponding log is as follows: raw_local_irq_restore() called with IRQs enabled WARNING: CPU: 96 PID: 2074 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x30/0x40 ... Call trace: warn_bogus_irq_restore+0x30/0x40 _raw_spin_unlock_irqrestore+0x84/0xc8 add_qp_to_list+0x11c/0x148 [hns_roce_hw_v2] hns_roce_create_qp_common.constprop.0+0x240/0x780 [hns_roce_hw_v2] hns_roce_create_qp+0x98/0x160 [hns_roce_hw_v2] create_qp+0x138/0x258 ib_create_qp_kernel+0x50/0xe8 create_mad_qp+0xa8/0x128 ib_mad_port_open+0x218/0x448 ib_mad_init_device+0x70/0x1f8 add_client_context+0xfc/0x220 enable_device_and_get+0xd0/0x140 ib_register_device.part.0+0xf4/0x1c8 ib_register_device+0x34/0x50 hns_roce_register_device+0x174/0x3d0 [hns_roce_hw_v2] hns_roce_init+0xfc/0x2c0 [hns_roce_hw_v2] __hns_roce_hw_v2_init_instance+0x7c/0x1d0 [hns_roce_hw_v2] hns_roce_hw_v2_init_instance+0x9c/0x180 [hns_roce_hw_v2]

In the Linux kernel, the following vulnerability has been resolved: KVM: Use dedicated mutex to protect kvm_usage_count to avoid deadlock Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock on x86 due to a chain of locks and SRCU synchronizations. Translating the below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the fairness of r/w semaphores). CPU0 CPU1 CPU2 1 lock(&kvm->slots_lock); 2 lock(&vcpu->mutex); 3 lock(&kvm->srcu); 4 lock(cpu_hotplug_lock); 5 lock(kvm_lock); 6 lock(&kvm->slots_lock); 7 lock(cpu_hotplug_lock); 8 sync(&kvm->srcu); Note, there are likely more potential deadlocks in KVM x86, e.g. the same pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with __kvmclock_cpufreq_notifier(): cpuhp_cpufreq_online() | -> cpufreq_online() | -> cpufreq_gov_performance_limits() | -> __cpufreq_driver_target() | -> __target_index() | -> cpufreq_freq_transition_begin() | -> cpufreq_notify_transition() | -> ... __kvmclock_cpufreq_notifier() But, actually triggering such deadlocks is beyond rare due to the combination of dependencies and timings involved. E.g. the cpufreq notifier is only used on older CPUs without a constant TSC, mucking with the NX hugepage mitigation while VMs are running is very uncommon, and doing so while also onlining/offlining a CPU (necessary to generate contention on cpu_hotplug_lock) would be even more unusual. The most robust solution to the general cpu_hotplug_lock issue is likely to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq notifier doesn't to take kvm_lock. For now, settle for fixing the most blatant deadlock, as switching to an RCU-protected list is a much more involved change, but add a comment in locking.rst to call out that care needs to be taken when walking holding kvm_lock and walking vm_list. ====================================================== WARNING: possible circular locking dependency detected 6.10.0-smp--c257535a0c9d-pip #330 Tainted: G S O ------------------------------------------------------ tee/35048 is trying to acquire lock: ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm] but task is already holding lock: ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (kvm_lock){+.+.}-{3:3}: __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 kvm_dev_ioctl+0x4fb/0xe50 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #2 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x2e/0xb0 static_key_slow_inc+0x16/0x30 kvm_lapic_set_base+0x6a/0x1c0 [kvm] kvm_set_apic_base+0x8f/0xe0 [kvm] kvm_set_msr_common+0x9ae/0xf80 [kvm] vmx_set_msr+0xa54/0xbe0 [kvm_intel] __kvm_set_msr+0xb6/0x1a0 [kvm] kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm] kvm_vcpu_ioctl+0x485/0x5b0 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&kvm->srcu){.+.+}-{0:0}: __synchronize_srcu+0x44/0x1a0 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: erofs: handle overlapped pclusters out of crafted images properly syzbot reported a task hang issue due to a deadlock case where it is waiting for the folio lock of a cached folio that will be used for cache I/Os. After looking into the crafted fuzzed image, I found it's formed with several overlapped big pclusters as below: Ext: logical offset | length : physical offset | length 0: 0.. 16384 | 16384 : 151552.. 167936 | 16384 1: 16384.. 32768 | 16384 : 155648.. 172032 | 16384 2: 32768.. 49152 | 16384 : 537223168.. 537239552 | 16384 ... Here, extent 0/1 are physically overlapped although it's entirely _impossible_ for normal filesystem images generated by mkfs. First, managed folios containing compressed data will be marked as up-to-date and then unlocked immediately (unlike in-place folios) when compressed I/Os are complete. If physical blocks are not submitted in the incremental order, there should be separate BIOs to avoid dependency issues. However, the current code mis-arranges z_erofs_fill_bio_vec() and BIO submission which causes unexpected BIO waits. Second, managed folios will be connected to their own pclusters for efficient inter-queries. However, this is somewhat hard to implement easily if overlapped big pclusters exist. Again, these only appear in fuzzed images so let's simply fall back to temporary short-lived pages for correctness. Additionally, it justifies that referenced managed folios cannot be truncated for now and reverts part of commit 2080ca1ed3e4 ("erofs: tidy up `struct z_erofs_bvec`") for simplicity although it shouldn't be any difference.