INFO: task syz.1.4619:23331 blocked for more than 143 seconds.
Not tainted 6.15.0-rc3-syzkaller-00001-g9d7a0577c9db #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.4619 state:D stack:27944 pid:23331 tgid:23326 ppid:20293 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x1b33/0x51f0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x163/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746
bdev_release+0x17e/0x700 block/bdev.c:1090
blkdev_release+0x15/0x20 block/fops.c:660
__fput+0x3e9/0x9f0 fs/file_table.c:465
task_work_run+0x251/0x310 kernel/task_work.c:227
get_signal+0x15db/0x1730 kernel/signal.c:2807
arch_do_signal_or_restart+0x98/0x810 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
do_syscall_64+0x100/0x210 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f198338e169
RSP: 002b:00007f1984248038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f19835b6080 RCX: 00007f198338e169
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f1983410a68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f19835b6080 R15: 00007ffc3796d7c8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764
2 locks held by getty/5582:
#0: ffff8880358aa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036b62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222
2 locks held by kworker/1:5/5881:
1 lock held by udevd/20273:
#0: ffff888025ecb358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf7/0xcd0 block/bdev.c:907
1 lock held by syz.1.4619/23331:
#0: ffff888025ecb358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x17e/0x700 block/bdev.c:1090
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00001-g9d7a0577c9db #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0x1058/0x10a0 kernel/hung_task.c:437
kthread+0x7b7/0x940 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 6054 Comm: kworker/u8:11 Not tainted 6.15.0-rc3-syzkaller-00001-g9d7a0577c9db #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4902 [inline]
RIP: 0010:__lock_acquire+0x5a5/0xd80 kernel/locking/lockdep.c:5185
Code: ff ff 89 d0 e9 44 ff ff ff 48 c7 c7 f0 ef c0 8e 48 89 de 44 89 c5 e8 4a 95 99 03 41 89 e8 e9 51 ff ff ff 44 89 f0 38 44 24 34 <4c> 8b 64 24 38 4c 8b 74 24 20 76 1c 44 89 c5 e8 47 30 5a 03 41 89
RSP: 0018:ffffc9000ad87328 EFLAGS: 00000093
RAX: 0000000000000003 RBX: 0000000000000004 RCX: 0000000000000004
RDX: 0000000000000003 RSI: 0000000000000004 RDI: 0000000000000000
RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88807726c7b0
R13: ffff88807726bc00 R14: 0000000000000003 R15: 0000000000000004
FS: 0000000000000000(0000) GS:ffff8881250cf000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e8a1c80600 CR3: 000000000eb38000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd5/0x23b0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4161 [inline]
slab_alloc_node mm/slub.c:4210 [inline]
kmem_cache_alloc_node_noprof+0x1f2/0x3b0 mm/slub.c:4262
__alloc_skb+0x1c2/0x480 net/core/skbuff.c:658
alloc_skb include/linux/skbuff.h:1340 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x260/0xb50 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
worker_thread+0x870/0xd50 kernel/workqueue.c:3400
kthread+0x7b7/0x940 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245