INFO: task syz-executor.4:24977 blocked for more than 143 seconds.
Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D29136 24977 10031 0x00004006
Call Trace:
context_switch kernel/sched/core.c:3380 [inline]
__schedule+0x934/0x1f90 kernel/sched/core.c:4080
schedule+0xdc/0x2b0 kernel/sched/core.c:4154
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
__mutex_lock_common kernel/locking/mutex.c:1033 [inline]
__mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
vivid_fop_release+0x66/0x480 drivers/media/platform/vivid/vivid-core.c:574
v4l2_release+0x21f/0x390 drivers/media/v4l2-core/v4l2-dev.c:452
__fput+0x2ff/0x890 fs/file_table.c:280
____fput+0x16/0x20 fs/file_table.c:313
task_work_run+0x145/0x1c0 kernel/task_work.c:113
get_signal+0x206e/0x24f0 kernel/signal.c:2528
do_signal+0x87/0x1700 arch/x86/kernel/signal.c:813
exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:160
prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c479
Code: Bad RIP value.
RSP: 002b:00007f856a6aec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffe00 RBX: 00007f856a6af6d4 RCX: 000000000045c479
RDX: 0000000020000200 RSI: 00000000c100565c RDI: 0000000000000005
RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000005ff R14: 00000000004c877d R15: 000000000076c06c
Showing all locks held in the system:
1 lock held by khungtaskd/885:
#0: ffffffff89bac340 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5333
1 lock held by rsyslogd/9883:
#0: ffff8880a91396a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:821
2 locks held by getty/9973:
#0: ffff8880978f6090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
#1: ffffc9000596b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/9974:
#0: ffff88809c1b0090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
#1: ffffc900059db2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/9975:
#0: ffff888098f20090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
#1: ffffc9000598b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/9976:
#0: ffff88809b730090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
#1: ffffc900059cb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/9977:
#0: ffff8880a7343090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
#1: ffffc900059a72e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/9978:
#0: ffff88809fdba090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
#1: ffffc900059eb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/9979:
#0: ffff8880a232f090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
#1: ffffc9000592b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by kworker/1:0/10050:
#0: ffff8880aa436928 ((wq_completion)rcu_gp){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline]
#0: ffff8880aa436928 ((wq_completion)rcu_gp){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff8880aa436928 ((wq_completion)rcu_gp){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
#0: ffff8880aa436928 ((wq_completion)rcu_gp){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
#0: ffff8880aa436928 ((wq_completion)rcu_gp){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline]
#0: ffff8880aa436928 ((wq_completion)rcu_gp){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline]
#0: ffff8880aa436928 ((wq_completion)rcu_gp){+.+.}, at: process_one_work+0x8dd/0x17a0 kernel/workqueue.c:2235
#1: ffffc90003fcfdc0 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x917/0x17a0 kernel/workqueue.c:2239
5 locks held by kworker/u4:16/13821:
#0: ffff8880a9a85928 ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline]
#0: ffff8880a9a85928 ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff8880a9a85928 ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
#0: ffff8880a9a85928 ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
#0: ffff8880a9a85928 ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline]
#0: ffff8880a9a85928 ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline]
#0: ffff8880a9a85928 ((wq_completion)netns){+.+.}, at: process_one_work+0x8dd/0x17a0 kernel/workqueue.c:2235
#1: ffffc90015cb7dc0 (net_cleanup_work){+.+.}, at: process_one_work+0x917/0x17a0 kernel/workqueue.c:2239
#2: ffffffff8a7421c8 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa1/0xb10 net/core/net_namespace.c:551
#3: ffffffff8a74de80 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
#4: ffffffff89bb0178 (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#4: ffffffff89bb0178 (rcu_state.exp_mutex){+.+.}, at: synchronize_rcu_expedited+0x4d6/0x5f0 kernel/rcu/tree_exp.h:851
6 locks held by kworker/u4:0/30823:
1 lock held by syz-executor.4/24448:
2 locks held by syz-executor.4/24977:
#0: ffff888216f80420 (&mdev->req_queue_mutex){+.+.}, at: v4l2_release+0x1d7/0x390 drivers/media/v4l2-core/v4l2-dev.c:451
#1: ffff888216f864a8 (&dev->mutex#3){+.+.}, at: vivid_fop_release+0x66/0x480 drivers/media/platform/vivid/vivid-core.c:574
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 885 Comm: khungtaskd Not tainted 5.6.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x197/0x210 lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
watchdog+0xb11/0x10c0 kernel/hung_task.c:289
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10004 Comm: syz-fuzzer Not tainted 5.6.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0033:0x4206b5
Code: cb 89 f1 41 89 fc d3 ef 49 83 fb 08 74 0a 0f ba e7 04 0f 83 c2 00 00 00 41 0f a3 cc 73 b8 4b 8d 3c 0b 48 8b 3f 48 85 ff 74 ac <49> 89 fc 4c 29 cf 48 39 d7 72 a1 4c 89 44 24 70 89 44 24 38 89 4c
RSP: 002b:000000c000121ea8 EFLAGS: 00000206
RAX: 0000000000203007 RBX: 00007f628988fc00 RCX: 0000000000000001
RDX: 0000000000000080 RSI: 0000000000000001 RDI: 000000c01e23ffc0
RBP: 000000c000121f28 R08: 00007f628997cfff R09: 000000c01e258000
R10: 000000c00002f770 R11: 0000000000000008 R12: 00000000000000da
R13: 0000000000000001 R14: 000000c018c35680 R15: 0000000000000000
FS: 000000c00007c090 GS: 0000000000000000