INFO: task kworker/u8:11:14668 blocked for more than 143 seconds.
Tainted: G W syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:11 state:D stack:21192 pid:14668 tgid:14668 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:1)
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
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:132
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x6f4/0x1000 fs/fs-writeback.c:1745
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_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xaf4/0xf00 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+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G W syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17856 Comm: syz.8.1040 Tainted: G W syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:preempt_latency_start kernel/sched/core.c:5809 [inline]
RIP: 0010:preempt_count_add+0x9e/0x1a0 kernel/sched/core.c:5832
Code: 65 8b 05 a5 f2 65 10 25 ff ff ff 7f 39 f8 75 43 48 8b 5c 24 18 48 89 df e8 0f c2 0c 00 85 c0 74 09 31 db 31 ff e8 02 c2 0c 00 <65> 4c 8b 34 25 08 b0 f5 91 49 81 c6 f0 14 00 00 4c 89 f0 48 c1 e8
RSP: 0018:ffffc90004fef620 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff81901bcb RCX: ffffffff9900e300
RDX: ffff88802ef25d80 RSI: ffffffff8b620c60 RDI: ffffffff81901bcb
RBP: ffffc90004fef730 R08: ffffffff8f1d3e37 R09: 1ffffffff1e3a7c6
R10: dffffc0000000000 R11: fffffbfff1e3a7c7 R12: ffff88802ef25d70
R13: 1ffff920009fded0 R14: ffff88802ef25940 R15: dffffc0000000000
FS: 00007f46ad2de6c0(0000) GS:ffff8881269c5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055930c82c950 CR3: 000000007fbd6000 CR4: 00000000003526f0
Call Trace:
class_preempt_constructor include/linux/preempt.h:472 [inline]
migrate_enable+0xdb/0x3c0 kernel/sched/core.c:2431
__free_frozen_pages+0x73b/0xce0 mm/page_alloc.c:2924
vfree+0x2ad/0x470 mm/vmalloc.c:3434
bch2_fs_btree_write_buffer_exit+0x179/0x1e0 fs/bcachefs/btree_write_buffer.c:870
__bch2_fs_free fs/bcachefs/super.c:615 [inline]
bch2_fs_release+0x297/0x830 fs/bcachefs/super.c:667
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x22b/0x480 lib/kobject.c:737
bch2_fs_get_tree+0xb6e/0x1520 fs/bcachefs/fs.c:2604
vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4324
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: 0033:0x7f46af08038a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f46ad2dde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f46ad2ddef0 RCX: 00007f46af08038a
RDX: 00002000000000c0 RSI: 0000200000000040 RDI: 00007f46ad2ddeb0
RBP: 00002000000000c0 R08: 00007f46ad2ddef0 R09: 0000000000810000
R10: 0000000000810000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f46ad2ddeb0 R14: 000000000000598f R15: 0000200000000280