INFO: task kworker/u4:4:1198 blocked for more than 143 seconds. Not tainted 5.15.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:4 state:D stack:21088 pid: 1198 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 exfat_write_inode+0x65/0x110 fs/exfat/inode.c:87 write_inode fs/fs-writeback.c:1495 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1705 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:2001 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2106 wb_check_background_flush fs/fs-writeback.c:2172 [inline] wb_do_writeback fs/fs-writeback.c:2260 [inline] wb_workfn+0xd07/0x1130 fs/fs-writeback.c:2288 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 INFO: task kworker/u4:5:1243 blocked for more than 143 seconds. Not tainted 5.15.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:22680 pid: 1243 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:4) Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 exfat_write_inode+0x65/0x110 fs/exfat/inode.c:87 write_inode fs/fs-writeback.c:1495 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1705 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:2001 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2106 wb_check_background_flush fs/fs-writeback.c:2172 [inline] wb_do_writeback fs/fs-writeback.c:2260 [inline] wb_workfn+0xd07/0x1130 fs/fs-writeback.c:2288 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:4/1198: #0: ffff88801419c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90004f37d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff88805acd40e0 (&type->s_umount_key#71){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff88805acd20e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_write_inode+0x65/0x110 fs/exfat/inode.c:87 4 locks held by kworker/u4:5/1243: #0: ffff88801419c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90005167d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff888065ef80e0 (&type->s_umount_key#71){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff888078db20e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_write_inode+0x65/0x110 fs/exfat/inode.c:87 2 locks held by getty/3258: #0: ffff888024aa4098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900024b32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 3 locks held by syz-executor.0/3516: 3 locks held by syz-executor.4/3837: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.157-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 154 Comm: kworker/u4:2 Not tainted 5.15.157-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: phy4 ieee80211_iface_work RIP: 0010:match_held_lock+0x0/0xb0 kernel/locking/lockdep.c:5070 Code: c6 03 00 75 cf 48 c7 c7 20 28 8b 8a 48 c7 c6 60 28 8b 8a e8 82 32 2e f7 0f 0b eb b6 e8 09 fb ff ff 66 0f 1f 84 00 00 00 00 00 <55> 53 bd 01 00 00 00 48 39 77 10 74 67 48 89 fb 81 7f 20 00 00 10 RSP: 0018:ffffc900010cf410 EFLAGS: 00000087 RAX: 0000000000000004 RBX: 0000000000000002 RCX: ffff8880133cbb80 RDX: ffff8880133cbb80 RSI: ffff888075458168 RDI: ffff8880133cc6c0 RBP: ffff8880133cc6c0 R08: ffffffff89904030 R09: ffffffff8990d835 R10: 0000000000000002 R11: ffff8880133cbb80 R12: 0000000000000246 R13: ffff8880133cbb80 R14: 00000000ffffffff R15: ffff888075458168 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005639d4d0f600 CR3: 00000000641c9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held kernel/locking/lockdep.c:5366 [inline] lock_is_held_type+0xa4/0x180 kernel/locking/lockdep.c:5666 lock_is_held include/linux/lockdep.h:287 [inline] cfg80211_update_known_bss+0x71/0x9e0 net/wireless/scan.c:1675 cfg80211_bss_update+0x187/0x21e0 net/wireless/scan.c:1771 cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2492 [inline] cfg80211_inform_bss_frame_data+0xa13/0x20f0 net/wireless/scan.c:2525 ieee80211_bss_info_update+0x7a6/0xc80 net/mac80211/scan.c:190 ieee80211_rx_bss_info net/mac80211/ibss.c:1123 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1614 [inline] ieee80211_ibss_rx_queued_mgmt+0x175e/0x2af0 net/mac80211/ibss.c:1643 ieee80211_iface_process_skb net/mac80211/iface.c:1441 [inline] ieee80211_iface_work+0x78f/0xcc0 net/mac80211/iface.c:1495 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300