INFO: task syz.1.342:7247 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.342 state:D stack:26992 pid:7247 ppid:5783 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
sync_bdevs+0x1af/0x330 block/bdev.c:1059
ksys_sync+0xba/0x150 fs/sync.c:105
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdcb1d8ebe9
RSP: 002b:00007fdcaffd5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fdcb1fc6090 RCX: 00007fdcb1d8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fdcb1fc6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdcb1fc6128 R14: 00007fdcb1fc6090 R15: 00007ffc6f527958
Showing all locks held in the system:
1 lock held by khungtaskd/28:
#0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:2/41:
2 locks held by getty/5546:
#0: ffff88802ce160a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by udevd/5777:
#0: ffff888021de04c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
2 locks held by kworker/1:4/5834:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000479fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000479fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by syz.1.342/7247:
#0: ffff888021de04c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1059
1 lock held by syz.0.431/7601:
#0: ffff888021de04c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1059
1 lock held by syz.3.432/7604:
#0: ffff888021de04c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1059
1 lock held by syz.2.434/7608:
#0: ffff888021de04c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1059
1 lock held by syz.7.570/8282:
#0: ffff88801d7b20e0 (&type->s_umount_key#80/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352
2 locks held by udevadm/8310:
2 locks held by cmp/8311:
2 locks held by syz.8.572/8313:
#0: ffffffff8cbece88 (sched_core_mutex){+.+.}-{3:3}, at: sched_core_get+0x52/0x180 kernel/sched/core.c:419
#1: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd35bb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
1 lock held by syz.8.572/8316:
1 lock held by rm/8315:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8316 Comm: syz.8.572 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__sanitizer_cov_trace_switch+0xf/0x120 kernel/kcov.c:333
Code: 02 48 c7 44 0a 08 07 00 00 00 48 89 7c 0a 10 48 89 74 0a 18 48 89 44 0a 20 c3 90 f3 0f 1e fa 48 8b 06 48 8b 4e 08 48 83 c1 f8 <48> c1 c1 3d 48 83 f9 02 7f 1e 48 85 c9 74 3c 48 83 f9 01 0f 85 ee
RSP: 0018:ffffc900049cef28 EFLAGS: 00000203
RAX: 0000000000000002 RBX: ffffffff8ecd0f14 RCX: 0000000000000008
RDX: ffffc90024018000 RSI: ffffffff8cb9e500 RDI: 0000000000000002
RBP: ffffc900049cf0b8 R08: ffffc900049cf001 R09: 0000000000000000
R10: ffffc900049cf068 R11: fffff52000939e19 R12: ffffc900049cf068
R13: dffffc0000000000 R14: 0000000000000002 R15: ffffffff8ecd0f19
FS: 00007f23392866c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f232f1f6000 CR3: 000000004672d000 CR4: 00000000003506f0
Call Trace:
unwind_next_frame+0x655/0x2970 arch/x86/kernel/unwind_orc.c:505
__unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:128
__set_page_owner+0x1d/0x60 mm/page_owner.c:192
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
__folio_alloc+0x10/0x20 mm/page_alloc.c:4489
vma_alloc_folio+0x47a/0x8f0 mm/mempolicy.c:2242
shmem_alloc_folio+0x179/0x230 mm/shmem.c:1680
shmem_alloc_and_acct_folio+0x189/0x630 mm/shmem.c:1705
shmem_get_folio_gfp+0xcde/0x2ac0 mm/shmem.c:2042
shmem_get_folio mm/shmem.c:2165 [inline]
shmem_write_begin+0xf2/0x420 mm/shmem.c:2707
generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4016
shmem_file_write_iter+0xfb/0x120 mm/shmem.c:2884
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x43b/0x940 fs/read_write.c:584
ksys_write+0x147/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f233838d69f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f2339285df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f233838d69f
RDX: 0000000001000000 RSI: 00007f232e1f7000 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000061ca
R10: 0000200000016fc2 R11: 0000000000000293 R12: 0000000000000006
R13: 00007f2339285ef0 R14: 00007f2339285eb0 R15: 00007f232e1f7000