INFO: task syz.2.5131:19285 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.5131 state:D stack:27560 pid:19285 ppid:12686 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: 0033:0x7fed68b8eec9
RSP: 002b:00007fed69a8a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fed68de5fa0 RCX: 00007fed68b8eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fed68de5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fed68de6038 R14: 00007fed68de5fa0 R15: 00007ffd574e1f08
Showing all locks held in the system:
3 locks held by kworker/u4:1/12:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by udevd/5158:
1 lock held by dhcpcd/5452:
2 locks held by getty/5550:
#0: ffff8880309ca0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by dhcpcd/5589:
1 lock held by udevd/8138:
#0: ffff888021d044c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
1 lock held by dhcpcd/12236:
1 lock held by dhcpcd/12415:
1 lock held by syz.2.5131/19285:
#0: ffff888021d044c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1059
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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: 5594 Comm: dhcpcd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline]
RIP: 0010:kasan_check_range+0x16/0x290 mm/kasan/generic.c:187
Code: ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc 66 0f 1f 00 b0 01 48 85 f6 0f 84 b8 01 00 00 55 41 57 41 56 41 55 <41> 54 53 4c 8d 04 37 49 39 f8 0f 82 5a 02 00 00 49 89 f9 49 c1 e9
RSP: 0018:ffffc90003a97798 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffff8880285bbc00 RCX: ffffffff8167b094
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90da7530
RBP: 0000000000000003 R08: dffffc0000000000 R09: 1ffffffff21b4ea6
R10: dffffc0000000000 R11: fffffbfff21b4ea7 R12: 0000000000000008
R13: dffffc0000000000 R14: ffff8880285bc6e0 R15: 00000000000001ab
FS: 00007fb3847d6740(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055682d9f9f60 CR3: 0000000028502000 CR4: 00000000003506f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
hlock_class kernel/locking/lockdep.c:228 [inline]
mark_lock+0x94/0x320 kernel/locking/lockdep.c:4656
mark_usage kernel/locking/lockdep.c:4579 [inline]
__lock_acquire+0x110b/0x7c80 kernel/locking/lockdep.c:5091
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__might_fault+0xc6/0x120 mm/memory.c:5946
_copy_to_user+0x2a/0xa0 lib/usercopy.c:36
copy_to_user include/linux/uaccess.h:191 [inline]
copy_siginfo_to_user+0x24/0xa0 kernel/signal.c:3372
x64_setup_rt_frame+0x740/0xcd0 arch/x86/kernel/signal_64.c:194
setup_rt_frame arch/x86/kernel/signal.c:223 [inline]
handle_signal arch/x86/kernel/signal.c:267 [inline]
arch_do_signal_or_restart+0x3e5/0x780 arch/x86/kernel/signal.c:312
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb384860407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff0b7757e0 EFLAGS: 00000202 ORIG_RAX: 000000000000010f
RAX: fffffffffffffffc RBX: 00007fb3847d6740 RCX: 00007fb384860407
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 000055682d9dd510
RBP: 00007fff0b775b20 R08: 0000000000000008 R09: 0000000000000000
R10: 00007fff0b775b20 R11: 0000000000000202 R12: 00005567ff5ad5e0
R13: 000055682d9d0df0 R14: 00000000ffffffff R15: 00007fff0b7758d0