INFO: task syz.1.1619:10667 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1619 state:D stack:27784 pid:10667 ppid:5775 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
blkdev_open+0x152/0x360 block/fops.c:589
do_dentry_open+0x8c6/0x1500 fs/open.c:929
do_open fs/namei.c:3640 [inline]
path_openat+0x27f1/0x3230 fs/namei.c:3797
do_filp_open+0x1f5/0x430 fs/namei.c:3824
do_sys_openat2+0x134/0x1d0 fs/open.c:1421
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1447
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f90c415b78e
RSP: 002b:00007f90c4f6fb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f90c4f706c0 RCX: 00007f90c415b78e
RDX: 0000000000002400 RSI: 00007f90c4f6fc00 RDI: ffffffffffffff9c
RBP: 00007f90c4f6fc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f90c4416038 R14: 00007f90c4415fa0 R15: 00007ffc00580308
Showing all locks held in the system:
1 lock held by ksoftirqd/1/22:
1 lock held by khungtaskd/29:
#0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:7/2920:
#0: ffff888018bfe538 (
(wq_completion)iou_exit
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:2609 [inline]
, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc9000c1e7d00
((work_completion)(&ctx->exit_work)
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:2609 [inline]
, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
2 locks held by getty/5530:
#0: ffff888031aba0a0 (&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+0x433/0x1390 drivers/tty/n_tty.c:2217
1 lock held by udevd/5912:
#0: ffff8880222d34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by syz.1.1619/10667:
#0: ffff8880222d34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by syz-executor/12213:
3 locks held by syz.2.2492/13461:
#0: ffff888019e52418 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x21b/0x990 fs/read_write.c:580
#1: ffff88807ce809c0 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff88807ce809c0 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:2873
#2: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#2: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#2: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: blk_cgroup_congested+0x1f/0x220 block/blk-cgroup.c:2190
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Tainted: G D syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 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+0xf3d/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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1096 Comm: kworker/u4:6 Tainted: G D syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__sanitizer_cov_trace_switch+0x7/0x120 kernel/kcov.c:330
Code: ca 77 1e 49 ff c0 4c 89 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
RSP: 0018:ffffc90004a5f4d0 EFLAGS: 00000202
RAX: 0000000000000003 RBX: ffffffff8f89cd1f RCX: ffff888024278000
RDX: ffffc90004a5fad0 RSI: ffffffff8cfa07b0 RDI: 0000000000000002
RBP: ffffc90004a5f5f8 R08: ffff888024278000 R09: 0000000000000008
R10: 0000000000000009 R11: 0000000000000000 R12: ffffc90004a5f5a8
R13: dffffc0000000000 R14: 0000000000000002 R15: ffffffff8f89cd1e
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f425a3e0000 CR3: 0000000078c76000 CR4: 00000000003506e0
Call Trace:
unwind_next_frame+0xe46/0x2970 arch/x86/kernel/unwind_orc.c:581
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
__kmem_cache_free+0xba/0x1e0 mm/slub.c:3843
skb_kfree_head net/core/skbuff.c:949 [inline]
skb_free_head net/core/skbuff.c:961 [inline]
skb_release_data+0x634/0x800 net/core/skbuff.c:991
skb_release_all net/core/skbuff.c:1057 [inline]
__kfree_skb net/core/skbuff.c:1071 [inline]
consume_skb+0xb2/0x110 net/core/skbuff.c:1287
nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
nsim_dev_trap_report_work+0x76f/0xb00 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
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
vkms_vblank_simulate: vblank timer overrun