INFO: task syz.6.2381:12788 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.2381 state:D stack:25624 pid:12788 tgid:12787 ppid:6826 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x147b/0x4f50 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153
kthread_flush_worker+0x138/0x1a0 kernel/kthread.c:1559
__alloc_workqueue+0x1481/0x1b80 kernel/workqueue.c:5797
alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:5820
btrfs_init_workqueues+0x3de/0x680 fs/btrfs/disk-io.c:1992
open_ctree+0x1477/0x3da0 fs/btrfs/disk-io.c:3411
btrfs_fill_super fs/btrfs/super.c:981 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1944 [inline]
btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline]
btrfs_get_tree+0x1061/0x1920 fs/btrfs/super.c:2121
vfs_get_tree+0x92/0x2a0 fs/super.c:1751
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount+0x329/0xa50 fs/namespace.c:3712
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa7429cbf4a
RSP: 002b:00007fa740c25e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fa740c25ee0 RCX: 00007fa7429cbf4a
RDX: 00002000000055c0 RSI: 0000200000000000 RDI: 00007fa740c25ea0
RBP: 00002000000055c0 R08: 00007fa740c25ee0 R09: 000000000300000a
R10: 000000000300000a R11: 0000000000000246 R12: 0000200000000000
R13: 00007fa740c25ea0 R14: 00000000000055a3 R15: 0000200000000080
Showing all locks held in the system:
2 locks held by kworker/u8:1/13:
#0: ffff88813fe69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813fe69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc90000127bc0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90000127bc0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
1 lock held by khungtaskd/38:
#0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d9aea00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5561:
#0: ffff8880344340a0 (&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+0x462/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/8005:
4 locks held by udevd/8041:
4 locks held by kworker/u8:18/10215:
1 lock held by syz.6.2381/12788:
#0: ffff8880275420d0 (&type->s_umount_key#60/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344
4 locks held by syz-executor/14651:
2 locks held by syz.9.2504/16560:
3 locks held by syz.8.2506/16562:
4 locks held by syz.2.2507/16568:
2 locks held by sed/16600:
=============================================
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 10/25/2025
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8041 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x44/0xa0 kernel/kcov.c:314
Code: e0 00 00 ff 00 ba 00 01 00 00 23 91 7c 0b 00 00 41 89 d1 45 09 c1 74 12 45 85 c0 75 5f 85 d2 74 5b 83 b9 3c 16 00 00 00 74 52 <8b> 91 18 16 00 00 83 fa 03 75 47 48 8b 91 20 16 00 00 44 8b 89 1c
RSP: 0018:ffffc9000bc3f2d8 EFLAGS: 00000246
RAX: ffffffff81335810 RBX: 00007f4b3a41a636 RCX: ffff88803cc68000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc9000bc3f398 R11: ffffffff81ad10c0 R12: ffff88803cc68000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92001787e72
FS: 00007f4b3a2e2880(0000) GS:ffff8881268d9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b39995000 CR3: 000000002f00a000 CR4: 00000000003526f0
Call Trace:
in_gate_area_no_mm+0x20/0x60 arch/x86/entry/vsyscall/vsyscall_64.c:332
is_kernel_text include/linux/kallsyms.h:31 [inline]
core_kernel_text kernel/extable.c:68 [inline]
kernel_text_address+0x2d/0xe0 kernel/extable.c:99
__kernel_text_address+0xd/0x30 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x188/0x6a0 mm/slub.c:5270
anon_vma_chain_alloc mm/rmap.c:141 [inline]
anon_vma_clone+0xb8/0x4f0 mm/rmap.c:287
anon_vma_fork+0x79/0x500 mm/rmap.c:350
dup_mmap+0x980/0x1b70 mm/mmap.c:1790
dup_mm kernel/fork.c:1529 [inline]
copy_mm+0x13b/0x4b0 kernel/fork.c:1581
copy_process+0x16db/0x3a90 kernel/fork.c:2221
kernel_clone+0x249/0x7f0 kernel/fork.c:2651
__do_sys_clone kernel/fork.c:2792 [inline]
__se_sys_clone kernel/fork.c:2776 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2776
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b3a41a636
Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc7895ac90 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffc7895ac98 RCX: 00007f4b3a41a636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 000055753bc7c190 R08: 0000000000000000 R09: 000055750c962140
R10: 00007f4b3a2e2b50 R11: 0000000000000246 R12: 000055753bc6e500
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000