syzbot


INFO: task hung in _vb2_fop_release

Status: auto-closed as invalid on 2019/07/09 20:36
Subsystems: media
[Documentation on labels]
First crash: 1942d, last: 1904d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in _vb2_fop_release (2) media 1 1339d 1339d 0/26 auto-closed as invalid on 2020/10/26 14:38

Sample crash report:
RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000000000080bae0 RDI: 0000000000000008
RBP: 000000c42728fa70 R08: 0000000000000008 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000743 R12: 000000c42728fb78
R13: 000000c42728fb78 R14: 0000000000000000 R15: 0000000000000000
INFO: task syz-executor5:31461 blocked for more than 140 seconds.
      Not tainted 4.20.0-rc5+ #142
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D23384 31461  21011 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2831 [inline]
 __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
 schedule+0xfe/0x460 kernel/sched/core.c:3516
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 _vb2_fop_release+0x3f/0x2b0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1008
 vb2_fop_release+0x77/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1024
 v4l2_release+0x2f2/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:459
 __fput+0x385/0xa30 fs/file_table.c:278
 ____fput+0x15/0x20 fs/file_table.c:309
 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x411021
Code: Bad RIP value.
RSP: 002b:00007ffd17ba0320 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000411021
RDX: 0000000000000000 RSI: 00000000007303d8 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffd17ba0240 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000178 R15: 0000000000000005

Showing all locks held in the system:
3 locks held by init/1:
1 lock held by khungtaskd/1020:
 #0: 0000000079c0e749 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379
2 locks held by kswapd0/1521:
4 locks held by rs:main Q:Reg/6064:
3 locks held by rsyslogd/6066:
3 locks held by cron/6116:
2 locks held by getty/6188:
 #0: 000000000cbb248c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000f93e4b6b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/6189:
 #0: 00000000c170e8e8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 000000003a5e5eb1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/6190:
 #0: 000000007dcca075 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 000000007f040610 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/6191:
 #0: 00000000eb9eb1ae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000d79a7f73 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/6192:
 #0: 0000000006eba281 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 000000009869dcca (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/6193:
 #0: 00000000f69ada1b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000d15ac5aa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/6194:
 #0: 000000004888fd4f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 0000000027dca87b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by syz-fuzzer/6214:
 #0: 000000008a9025f5 (&mm->mmap_sem){++++}, at: do_user_addr_fault arch/x86/mm/fault.c:1351 [inline]
 #0: 000000008a9025f5 (&mm->mmap_sem){++++}, at: __do_page_fault+0x3da/0xe60 arch/x86/mm/fault.c:1489
 #1: 00000000b2e7bd4c (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7a/0xad fs/ext4/inode.c:6291
3 locks held by syz-fuzzer/6215:
3 locks held by syz-fuzzer/6225:
2 locks held by kworker/u4:6/10156:
1 lock held by syz-executor5/31461:
 #0: 0000000055f7b4fa (&vcap->lock){+.+.}, at: _vb2_fop_release+0x3f/0x2b0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1008
Mem-Info:
active_anon:72364 inactive_anon:208 isolated_anon:0
 active_file:7052 inactive_file:6998 isolated_file:160
 unevictable:0 dirty:14187 writeback:0 unstable:0
 slab_reclaimable:13937 slab_unreclaimable:107271
 mapped:49154 shmem:350 pagetables:2102 bounce:0
 free:24250 free_pcp:0 free_cma:0
2 locks held by syz-executor5/31462:

=============================================

Node 0 active_anon:289456kB inactive_anon:832kB active_file:28484kB inactive_file:28060kB unevictable:0kB isolated(anon):0kB isolated(file):640kB mapped:196616kB dirty:56748kB writeback:0kB shmem:1400kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 165888kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no
NMI backtrace for cpu 0
CPU: 0 PID: 1020 Comm: khungtaskd Not tainted 4.20.0-rc5+ #142
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+0x244/0x39d lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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+0xb51/0x1060 kernel/hung_task.c:289
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 3.032 msecs
NMI backtrace for cpu 1
CPU: 1 PID: 1 Comm: init Not tainted 4.20.0-rc5+ #142
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x1/0x50 kernel/kcov.c:94
Code: dd 28 00 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d c3 66 90 55 <48> 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 f8 51 82
RSP: 0018:ffff8881d9a9bc40 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8393c18d
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: ffff8881d9a9bc80 R08: ffff8881d9a94040 R09: 0000000000000000
R10: fffffbfff128249a R11: ffffffff894124d7 R12: 0000000000000001
R13: ffffffff8860d520 R14: ffffffff88325420 R15: dead000000000100
FS:  00007f779014a7a0(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000410ff7 CR3: 00000001c4fda000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __this_cpu_preempt_check+0x1c/0x20 lib/smp_processor_id.c:62
 __count_memcg_events include/linux/memcontrol.h:726 [inline]
 count_memcg_events include/linux/memcontrol.h:741 [inline]
 count_memcg_page_event include/linux/memcontrol.h:749 [inline]
 shrink_page_list+0x35df/0xccd0 mm/vmscan.c:1490
 shrink_inactive_list+0x77b/0x1c60 mm/vmscan.c:1963
 shrink_list mm/vmscan.c:2275 [inline]
 shrink_node_memcg+0x78b/0x18f0 mm/vmscan.c:2540
 shrink_node+0x3bc/0x16b0 mm/vmscan.c:2755
 ? shrink_node_memcg+0x1
Lost 138 message(s)!
Node 0 DMA free:15908kB min:164kB low:204kB high:244kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/12/03 23:44 upstream 0072a0c14d5b 03f94a45 .config console log report ci-upstream-kasan-gce-selinux-root
2019/01/10 20:36 linux-next 6cab33afc3dd db9b6579 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.