INFO: task kworker/u8:3:50 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3 state:D stack:22280 pid:50 tgid:50 ppid:2 task_flags:0x4388060 flags:0x00080000
Workqueue: loop6 loop_workfn
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
inode_lock_shared include/linux/fs.h:995 [inline]
blkdev_write_iter+0x50b/0x710 block/fops.c:804
lo_rw_aio+0xcfa/0xfa0 include/linux/percpu-rwsem.h:-1
do_req_filebacked drivers/block/loop.c:-1 [inline]
loop_handle_cmd drivers/block/loop.c:1923 [inline]
loop_process_work+0x835/0xf90 drivers/block/loop.c:1958
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/50:
#0: ffff88806addc148 ((wq_completion)loop6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88806addc148 ((wq_completion)loop6){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90000bb7ba0 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90000bb7ba0 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff8880250f9328 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline]
#2: ffff8880250f9328 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_write_iter+0x50b/0x710 block/fops.c:804
2 locks held by getty/5592:
#0: ffff88814d2a30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/1:16/9460:
#0: ffff88801a055948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88801a055948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9001a63fba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9001a63fba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff888051bdf240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0 drivers/net/netdevsim/fib.c:1490
3 locks held by syz.5.1070/10835:
1 lock held by dhcpcd/11323:
#0: ffff888058b2f508 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
#0: ffff888058b2f508 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff888058b2f508 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
1 lock held by syz.8.1177/11496:
#0: ffff8880250f94c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline]
#0: ffff8880250f94c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494
1 lock held by syz.6.1197/11618:
#0: ffff8880250f94c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline]
#0: ffff8880250f94c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494
1 lock held by syz.6.1197/11619:
#0: ffff8880250f94c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline]
#0: ffff8880250f94c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494
1 lock held by syz.0.1456/12989:
#0: ffff8880250f94c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline]
#0: ffff8880250f94c8 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x3a2/0xe70 mm/readahead.c:494
1 lock held by syz-executor/13158:
#0: ffffffff8df42d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8df42d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
3 locks held by syz.7.1531/13328:
#0: ffff8880589f5288 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
#0: ffff8880589f5288 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff8880589f5288 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
#1: ffff8880333fa260 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1679 [inline]
#1: ffff8880333fa260 (sk_lock-AF_CAN){+.+.}-{0:0}, at: bcm_release+0x1cd/0x940 net/can/bcm.c:1601
#2: ffffffff8df42d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8df42d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by sed/13351:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:mark_lock+0x3c/0x190 kernel/locking/lockdep.c:4731
Code: 00 03 00 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45 da bd 01 00 00 00 89 d9 d3 e5 25 ff 1f 00 00 48 0f a3 05 64 51 d8 11 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 30 d3 16 93 eb 48 83 3d cb e0
RSP: 0018:ffffc90000ac77c0 EFLAGS: 00000003
RAX: 00000000000007f7 RBX: 0000000000000006 RCX: 0000000000000006
RDX: 0000000000000006 RSI: ffff88801e2fe618 RDI: ffff88801e2fdac0
RBP: 0000000000000040 R08: ffffffff8f7cd477 R09: 1ffffffff1ef9a8e
R10: dffffc0000000000 R11: fffffbfff1ef9a8f R12: ffff88801e2fe690
R13: 0000000000000000 R14: ffff88801e2fe618 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812623e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b55fced950 CR3: 000000000dd38000 CR4: 00000000003526f0
Call Trace:
mark_held_locks kernel/locking/lockdep.c:4325 [inline]
__trace_hardirqs_on_caller kernel/locking/lockdep.c:4351 [inline]
lockdep_hardirqs_on_prepare+0x191/0x2a0 kernel/locking/lockdep.c:4410
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78
kasan_quarantine_put+0xdd/0x220 mm/kasan/quarantine.c:234
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2539 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x19a/0x6d0 mm/slub.c:6837
skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1087
skb_release_all net/core/skbuff.c:1152 [inline]
__kfree_skb net/core/skbuff.c:1166 [inline]
consume_skb+0x9e/0xf0 net/core/skbuff.c:1398
nsim_dev_trap_report drivers/net/netdevsim/dev.c:836 [inline]
nsim_dev_trap_report_work+0x7cf/0xb80 drivers/net/netdevsim/dev.c:866
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245