INFO: task syz.1.9486:11924 blocked for more than 143 seconds.
Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.9486 state:D stack:26504 pid:11924 tgid:11923 ppid:4115 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
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
seq_read_iter+0x4ea/0xe10 fs/seq_file.c:230
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 fs/read_write.c:847 [inline]
vfs_readv+0x5a7/0x850 fs/read_write.c:1020
do_preadv fs/read_write.c:1132 [inline]
__do_sys_preadv fs/read_write.c:1179 [inline]
__se_sys_preadv fs/read_write.c:1174 [inline]
__x64_sys_preadv+0x197/0x2a0 fs/read_write.c:1174
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb60d58e929
RSP: 002b:00007fb60b3f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007fb60d7b5fa0 RCX: 00007fb60d58e929
RDX: 0000000000000001 RSI: 0000200000000040 RDI: 0000000000000008
RBP: 00007fb60d610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb60d7b5fa0 R15: 00007fffa433abd8
Showing all locks held in the system:
4 locks held by kworker/u8:1/13:
#0: ffff88801b6fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801b6fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8f715950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
#3: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:174 [inline]
#3: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:249
3 locks held by kworker/1:0/24:
#0: ffff88801a880d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a880d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc900001e7bc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900001e7bc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by khungtaskd/31:
#0: ffffffff8e33eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e33eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
3 locks held by kworker/u8:5/191:
#0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90002ff7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90002ff7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by dhcpcd/5501:
#0: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x20f/0x330 net/ipv6/addrconf.c:4803
2 locks held by getty/5599:
#0: ffff88814cb990a0 (&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
1 lock held by syz.9.8844/5426:
2 locks held by syz.1.9486/11924:
#0: ffff888057333c30 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182
#1: ffff88804d30a9d0 (&client->ioctl_mutex){+.+.}-{4:4}, at: snd_seq_info_clients_read+0x14a/0x7e0 sound/core/seq/seq_clientmgr.c:2743
3 locks held by syz.3.9802/14657:
#0: ffff888027de82b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1217
#1: ffff88802fadd540 (&p->lock){+.+.}-{4:4}, at: seq_lseek+0x52/0x260 fs/seq_file.c:313
#2: ffff88804d30a9d0 (&client->ioctl_mutex){+.+.}-{4:4}, at: snd_seq_info_clients_read+0x14a/0x7e0 sound/core/seq/seq_clientmgr.c:2743
3 locks held by syz.0.10068/16836:
#0: ffff88806495c638 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1217
#1: ffff88804f764d58 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182
#2: ffff88804d30a9d0 (&client->ioctl_mutex){+.+.}-{4:4}, at: snd_seq_info_clients_read+0x14a/0x7e0 sound/core/seq/seq_clientmgr.c:2743
2 locks held by syz-executor/18739:
#0: ffffffff8fc43418 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8fc43418 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8fc43418 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4054
2 locks held by syz.5.10302/18915:
#0: ffffffff8ef06048 (ppp_mutex){+.+.}-{4:4}, at: ppp_ioctl+0xcd/0x19a0 drivers/net/ppp/ppp_generic.c:741
#1: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3355 [inline]
#1: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1072 [inline]
#1: ffffffff8f722548 (rtnl_mutex){+.+.}-{4:4}, at: ppp_ioctl+0x695/0x19a0 drivers/net/ppp/ppp_generic.c:745
1 lock held by syz.6.10305/18928:
#0: ffffffff8e344780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3782
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #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:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
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: 12418 Comm: syz-executor Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:473 [inline]
RIP: 0010:lock_release+0x26e/0x3e0 kernel/locking/lockdep.c:5894
Code: 85 ee fe ff ff 41 8d 45 ff 48 83 c5 d8 45 85 ed 41 89 c5 7f d0 4c 89 ff 4c 89 f6 48 8b 54 24 18 e8 57 30 00 00 48 8b 5c 24 08 <48> c7 c7 71 ae c3 8d e8 e6 a9 ce 09 b8 ff ff ff ff 65 0f c1 05 19
RSP: 0018:ffffc9000ef674d0 EFLAGS: 00000046
RAX: ffffffffffffffff RBX: 0000000000000202 RCX: a87b2047b43a8d00
RDX: 0000000000000000 RSI: ffffffff8e33eda0 RDI: ffff88805f00c6f0
RBP: ffff88805f00c6f0 R08: ffffc9000ef67878 R09: 0000000000000000
R10: ffffc9000ef67658 R11: fffff52001dececd R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8e33eda0 R15: ffff88805f00bc00
FS: 0000000000000000(0000) GS:ffff888125b1c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c302647 CR3: 000000003471a000 CR4: 00000000003526f0
DR0: 0000000000000008 DR1: 00000000000000ff DR2: fffffffffffffffb
DR3: 3e00000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
__free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
vfree+0x25a/0x400 mm/vmalloc.c:3426
kcov_put kernel/kcov.c:439 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:535
__fput+0x44c/0xa70 fs/file_table.c:465
task_work_run+0x1d1/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6ad/0x22e0 kernel/exit.c:955
do_group_exit+0x21c/0x2d0 kernel/exit.c:1104
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7e715c11e5
Code: Unable to access opcode bytes at 0x7f7e715c11bb.
RSP: 002b:00007ffc7d1fa850 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 00000000000002e4 RCX: 00007f7e715c11e5
RDX: 00007ffc7d1fa890 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc7d1fa8fc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 00000000001b7e91 R15: 00007ffc7d1fa950