INFO: task syz.9.1317:13182 blocked for more than 143 seconds.
Not tainted 6.15.0-rc7-syzkaller-00144-gb1427432d3b6 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1317 state:D stack:24280 pid:13182 tgid:13180 ppid:9052 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 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+0x724/0xe80 kernel/locking/mutex.c:746
snd_seq_info_clients_read+0x14a/0x7e0 sound/core/seq/seq_clientmgr.c:2743
snd_info_seq_show+0xd9/0x100 sound/core/info.c:342
traverse+0x1e9/0x570 fs/seq_file.c:111
seq_read_iter+0xcfe/0xe10 fs/seq_file.c:195
seq_read+0x2e2/0x3d0 fs/seq_file.c:162
pde_read fs/proc/inode.c:308 [inline]
proc_reg_read+0x1e9/0x2e0 fs/proc/inode.c:320
do_loop_readv_writev include/linux/uio.h:-1 [inline]
vfs_readv+0x5a2/0x840 fs/read_write.c:1018
do_preadv fs/read_write.c:1130 [inline]
__do_sys_preadv fs/read_write.c:1177 [inline]
__se_sys_preadv fs/read_write.c:1172 [inline]
__x64_sys_preadv+0x197/0x2a0 fs/read_write.c:1172
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb499b8e969
RSP: 002b:00007fb4979f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007fb499db6080 RCX: 00007fb499b8e969
RDX: 0000000000000001 RSI: 0000200000004ec0 RDI: 0000000000000009
RBP: 00007fb499c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000008100 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb499db6080 R15: 00007fb499edfa28
Showing all locks held in the system:
7 locks held by kworker/1:0/24:
1 lock held by khungtaskd/31:
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
2 locks held by getty/5596:
#0: ffff8880346f10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000362c2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/1:4/5883:
#0: ffff8880b8839b58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:613
#1: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
6 locks held by kworker/0:8/9857:
#0: ffff8881446af148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8881446af148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000b5d7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000b5d7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffff888144fa0198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#2: ffff888144fa0198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5859
#3: ffff888060de7198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#3: ffff888060de7198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1004
#4: ffff88806dd50160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#4: ffff88806dd50160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1004
#5: ffffffff8dde4150 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0 kernel/umh.c:214
4 locks held by udevd/11746:
#0: ffff888051da8668 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182
#1: ffff8880589b8088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154
#2: ffff888032ef42d8 (kn->active#25){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:155
#3: ffff888060de7198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:927 [inline]
#3: ffff888060de7198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz.0.1158/12387:
#0: ffff88801e7921d0 (&client->ioctl_mutex){+.+.}-{4:4}, at: snd_seq_ioctl+0x232/0x420 sound/core/seq/seq_clientmgr.c:2384
2 locks held by syz.9.1317/13182:
#0: ffff888055f09e80 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182
#1: ffff88801e7921d0 (&client->ioctl_mutex){+.+.}-{4:4}, at: snd_seq_info_clients_read+0x14a/0x7e0 sound/core/seq/seq_clientmgr.c:2743
1 lock held by syz.7.1695/15109:
#0: ffff888144fa0198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#0: ffff888144fa0198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.5.1833/15848:
#0: ffffffff8df43880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774
1 lock held by syz.6.1851/15971:
#0: ffffffff8df43880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774
1 lock held by dhcpcd-run-hook/15991:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00144-gb1427432d3b6 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x70e/0x8a0 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: 15994 Comm: sed Not tainted 6.15.0-rc7-syzkaller-00144-gb1427432d3b6 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0033:0x7f5a106088f6
Code: 29 d7 eb 24 8b 4a 04 48 83 c0 13 48 83 e0 f8 48 8d 44 08 07 48 83 e0 f8 48 01 c2 48 8d 04 3a 4c 39 c0 0f 83 f4 00 00 00 8b 02 <83> f8 04 75 d5 83 7a 08 05 75 cf 81 7a 0c 47 4e 55 00 75 c6 8b 4a
RSP: 002b:00007fff880cb518 EFLAGS: 00000283
RAX: 0000000000000004 RBX: 00007f5a10356270 RCX: 000000000000000e
RDX: 00007f5a10522720 RSI: 00007f5a105f85f0 RDI: ffff80a5efadd8ec
RBP: 00007fff880cb990 R08: 0000000000000040 R09: 00000000effffef5
R10: 0000000070000029 R11: 00007fff880cb520 R12: 0000000000000003
R13: 00007f5a105f85f0 R14: 00007fff880cba30 R15: 00007f5a10529000
FS: 0000000000000000 GS: 0000000000000000