INFO: task kworker/u8:9:1391 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:9 state:D stack:20088 pid:1391 tgid:1391 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x81/0xe0 kernel/sched/core.c:7903 folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1317 folio_lock include/linux/pagemap.h:1133 [inline] writeback_get_folio mm/page-writeback.c:2468 [inline] writeback_iter+0x8d8/0x12a0 mm/page-writeback.c:2562 blkdev_writepages+0xb7/0x170 block/fops.c:483 do_writepages+0x32b/0x550 mm/page-writeback.c:2634 __writeback_single_inode+0x145/0x1000 fs/fs-writeback.c:1680 writeback_sb_inodes+0x6b7/0xf60 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158 wb_check_start_all fs/fs-writeback.c:2284 [inline] wb_do_writeback fs/fs-writeback.c:2310 [inline] wb_workfn+0x910/0xf00 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task udevd:6875 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:26312 pid:6875 tgid:6875 ppid:5207 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547 bdev_open+0xe0/0xcc0 block/bdev.c:945 blkdev_open+0x46c/0x610 block/fops.c:694 do_dentry_open+0x9ae/0x1350 fs/open.c:965 vfs_open+0x3b/0x350 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x2ef1/0x3840 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9a95479407 RSP: 002b:00007ffe5eee49f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f9a9538b880 RCX: 00007f9a95479407 RDX: 00000000000a0800 RSI: 000055670a6924f0 RDI: ffffffffffffff9c RBP: 000055670a600910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055670a620840 R13: 000055670a60e190 R14: 0000000000000000 R15: 000055670a620840 INFO: task syz.0.55:6894 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.55 state:D stack:25800 pid:6894 tgid:6891 ppid:6411 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x81/0xe0 kernel/sched/core.c:7903 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250 __wait_on_bit_lock+0xe3/0x4c0 kernel/sched/wait_bit.c:93 out_of_line_wait_on_bit_lock+0x123/0x170 kernel/sched/wait_bit.c:120 lock_buffer include/linux/buffer_head.h:432 [inline] hfs_mdb_commit+0x115/0x1160 fs/hfs/mdb.c:271 hfs_sync_fs+0x15/0x20 fs/hfs/super.c:37 __iterate_supers+0x13a/0x290 fs/super.c:924 ksys_sync+0xa3/0x150 fs/sync.c:103 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1c8c54ebe9 RSP: 002b:00007f1c8bbb6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f1c8c785fa0 RCX: 00007f1c8c54ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f1c8c785fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1c8c786038 R14: 00007f1c8c785fa0 R15: 00007ffee8f2f9b8 INFO: task syz.2.56:6895 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.56 state:D stack:25800 pid:6895 tgid:6892 ppid:6423 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x81/0xe0 kernel/sched/core.c:7903 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250 __wait_on_bit_lock+0xe3/0x4c0 kernel/sched/wait_bit.c:93 out_of_line_wait_on_bit_lock+0x123/0x170 kernel/sched/wait_bit.c:120 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline] __lock_buffer fs/buffer.c:71 [inline] lock_buffer include/linux/buffer_head.h:432 [inline] __block_write_full_folio+0x54f/0xe10 fs/buffer.c:1910 blkdev_writepages+0xd1/0x170 block/fops.c:484 do_writepages+0x32b/0x550 mm/page-writeback.c:2634 filemap_fdatawrite_wbc mm/filemap.c:386 [inline] __filemap_fdatawrite_range mm/filemap.c:419 [inline] __filemap_fdatawrite mm/filemap.c:425 [inline] filemap_fdatawrite+0x19c/0x240 mm/filemap.c:430 sync_bdevs+0x242/0x340 block/bdev.c:1300 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe49429ebe9 RSP: 002b:00007fe493906038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fe4944d5fa0 RCX: 00007fe49429ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fe4944d5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe4944d6038 R14: 00007fe4944d5fa0 R15: 00007ffcfd768cd8 INFO: task syz.4.21:6896 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.21 state:D stack:25800 pid:6896 tgid:6893 ppid:6421 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x81/0xe0 kernel/sched/core.c:7903 folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1317 folio_lock include/linux/pagemap.h:1133 [inline] __find_get_block_slow fs/buffer.c:205 [inline] find_get_block_common+0x2e6/0xfc0 fs/buffer.c:1408 bdev_getblk+0x4b/0x660 fs/buffer.c:-1 __bread_gfp+0x89/0x3c0 fs/buffer.c:1515 sb_bread include/linux/buffer_head.h:346 [inline] hfs_mdb_commit+0xa42/0x1160 fs/hfs/mdb.c:318 hfs_sync_fs+0x15/0x20 fs/hfs/super.c:37 __iterate_supers+0x13a/0x290 fs/super.c:924 ksys_sync+0xb2/0x150 fs/sync.c:104 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7f1127ebe9 RSP: 002b:00007f7f108e6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f7f114b5fa0 RCX: 00007f7f1127ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f7f114b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7f114b6038 R14: 00007f7f114b5fa0 R15: 00007ffcb41c0028 INFO: task syz.3.57:6899 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.57 state:D stack:25416 pid:6899 tgid:6897 ppid:6427 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x81/0xe0 kernel/sched/core.c:7903 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250 __wait_on_bit_lock+0xe3/0x4c0 kernel/sched/wait_bit.c:93 out_of_line_wait_on_bit_lock+0x123/0x170 kernel/sched/wait_bit.c:120 lock_buffer include/linux/buffer_head.h:432 [inline] hfs_mdb_commit+0x115/0x1160 fs/hfs/mdb.c:271 hfs_sync_fs+0x15/0x20 fs/hfs/super.c:37 __iterate_supers+0x13a/0x290 fs/super.c:924 ksys_sync+0xa3/0x150 fs/sync.c:103 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff464c8ebe9 RSP: 002b:00007ff4642fe038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007ff464ec5fa0 RCX: 00007ff464c8ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ff464ec5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff464ec6038 R14: 00007ff464ec5fa0 R15: 00007ffe9aba4358 INFO: task syz.1.58:6904 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.58 state:D stack:25800 pid:6904 tgid:6902 ppid:6414 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1b7/0xa50 fs/fs-writeback.c:2834 __iterate_supers+0x13a/0x290 fs/super.c:924 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9957c3ebe9 RSP: 002b:00007f99572a6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f9957e75fa0 RCX: 00007f9957c3ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f9957e75fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9957e76038 R14: 00007f9957e75fa0 R15: 00007fff6867c568 Showing all locks held in the system: 3 locks held by kworker/0:1/10: #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc900000f7bc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900000f7bc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff888055805260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x2ac/0x31b0 drivers/net/netdevsim/fib.c:1490 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:9/1391: #0: ffff88801f6d9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801f6d9138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000525fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000525fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff8881404980d0 (&type->s_umount_key#41){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 3 locks held by klogd/5196: 2 locks held by getty/5596: #0: ffff88823bf3a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:3/5916: #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90004ddfbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90004ddfbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff8880613e5260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x2ac/0x31b0 drivers/net/netdevsim/fib.c:1490 2 locks held by kworker/0:5/6699: #0: ffff888019899138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019899138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90003aa7bc0 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90003aa7bc0 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 1 lock held by udevd/6875: #0: ffff88802489a4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:945 1 lock held by syz.0.55/6894: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.2.56/6895: #0: ffff88802489a4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 1 lock held by syz.4.21/6896: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.3.57/6899: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by syz.1.58/6904: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.5.59/7107: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.9.63/7110: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.7.61/7113: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.8.62/7116: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.6.60/7120: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 1 lock held by syz-executor/7126: #0: ffff88802489a4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:945 2 locks held by syz.1.65/7215: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.3.67/7236: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.2.66/7239: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.4.68/7242: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.5.69/7332: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.9.70/7347: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.6.71/7380: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.8.73/7386: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by kworker/u8:20/7392: 1 lock held by syz-executor/7411: #0: ffff88802489a4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:945 3 locks held by kworker/1:9/7452: #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90005cffbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90005cffbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff888059da8260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x2ac/0x31b0 drivers/net/netdevsim/fib.c:1490 2 locks held by syz.7.72/7559: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.1.75/7571: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.2.77/7574: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 2 locks held by syz.3.76/7577: #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880590c00d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802488a870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2832 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:rdtsc_ordered arch/x86/include/asm/tsc.h:57 [inline] RIP: 0010:delay_tsc+0x71/0xc0 arch/x86/lib/delay.c:72 Code: 00 00 e8 82 00 9a f6 65 8b 05 ab 71 00 07 85 c0 74 1c f3 90 bf 01 00 00 00 e8 bb fe 99 f6 e8 46 3c 01 00 39 c5 75 0e 0f 01 f9 <66> 90 eb bd e8 66 a8 3d f6 eb dd 4c 29 fb e8 2c 3c 01 00 89 c5 0f RSP: 0018:ffffc90000167890 EFLAGS: 00000246 RAX: 00000000f51cac04 RBX: 0000000000000899 RCX: 0000000000000000 RDX: 00000000000000ad RSI: ffffffff8b6215e0 RDI: ffffffff8b6215a0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8af5ce30 R12: 1ffffffff3275d0e R13: 00000000ffffffff R14: 000000adf51ca9d2 R15: 00000000000001a6 FS: 0000000000000000(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2dc2421c CR3: 0000000035fc2000 CR4: 00000000003526f0 Call Trace: udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x166/0x2f0 drivers/tty/serial/8250/8250_port.c:1990 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3288 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3311 [inline] serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3396 console_emit_next_record kernel/printk/printk.c:3118 [inline] console_flush_all+0x695/0xcd0 kernel/printk/printk.c:3226 __console_flush_and_unlock+0xa4/0x240 kernel/printk/printk.c:3285 legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3638 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245