INFO: task syz.5.2426:15886 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.2426 state:D stack:28136 pid:15886 tgid:15884 ppid:7066 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x60e0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
sync_bdevs+0x153/0x480 block/bdev.c:1304
ksys_sync+0xb0/0xf0 fs/sync.c:105
__do_sys_sync+0xe/0x20 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f36a599c629
RSP: 002b:00007f36a3b91028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f36a5c16090 RCX: 00007f36a599c629
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f36a5c16090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f36a5c16128 R14: 00007f36a5c16090 R15: 00007ffc9da12ae8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5561:
#0: ffff888034a660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
2 locks held by kworker/u8:10/7017:
2 locks held by udevd/13354:
1 lock held by udevd/13363:
#0: ffff888027e33358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
1 lock held by syz.5.2426/15886:
#0: ffff888027e33358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304
6 locks held by syz.2.2917/17740:
#0: ffffffff8e7d59c0 (console_lock){+.+.}-{0:0}, at: class_console_lock_constructor include/linux/console.h:736 [inline]
#0: ffffffff8e7d59c0 (console_lock){+.+.}-{0:0}, at: vt_resizex drivers/tty/vt/vt_ioctl.c:700 [inline]
#0: ffffffff8e7d59c0 (console_lock){+.+.}-{0:0}, at: vt_ioctl+0x2657/0x31a0 drivers/tty/vt/vt_ioctl.c:923
#1: ffff888020fb4280 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_pan_display+0xd6/0xa40 drivers/gpu/drm/drm_fb_helper.c:1260
#2: ffff8880271f0130 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_internal_acquire+0x21/0x80 drivers/gpu/drm/drm_auth.c:435
#3: ffff888020fb4098 (&client->modeset_mutex){+.+.}-{4:4}, at: drm_client_modeset_commit_locked+0x4c/0x580 drivers/gpu/drm/drm_client_modeset.c:1204
#4: ffffc90005687300 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_client_modeset_commit_atomic+0xc4/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1042
#5: ffffc90005687328 (crtc_ww_class_mutex){+.+.}-{4:4}, at: drm_client_modeset_commit_atomic+0xc4/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1042
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
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: 16 Comm: rcu_preempt Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3802 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3876 [inline]
RIP: 0010:__lock_acquire+0x879/0x2630 kernel/locking/lockdep.c:5237
Code: 4d 0f af e7 49 c1 ec 2d 4a 8b 04 e5 60 dc 51 97 4e 8d 34 e5 60 dc 51 97 48 85 c0 74 1f 48 83 e8 08 48 85 c0 74 16 48 8b 50 18 <49> 39 d7 0f 84 a7 fd ff ff 48 8b 40 08 48 85 c0 75 e1 8b 0d ef 58
RSP: 0018:ffffc90000157b60 EFLAGS: 00000082
RAX: ffffffff94146540 RBX: ffff88801e6a8b18 RCX: 0000000000000000
RDX: 381b898d1068a33d RSI: 000000006ad06a09 RDI: 00000000ffed9324
RBP: ffff88801e6a8000 R08: 00000000951d291b R09: 0000000000000047
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000002428f
R13: 0000000000000047 R14: ffffffff9763f0d8 R15: 381b898d1068a33d
FS: 0000000000000000(0000) GS:ffff888124448000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbfa53e6158 CR3: 000000003620b000 CR4: 00000000003526f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170
rcu_gp_init+0x9a/0x1480 kernel/rcu/tree.c:1815
rcu_gp_kthread+0xb2/0x230 kernel/rcu/tree.c:2287
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245