syzbot


INFO: task hung in odev_release

Status: auto-obsoleted due to no activity on 2024/07/02 14:50
Reported-by: syzbot+95c416c720e351f6e8b6@syzkaller.appspotmail.com
First crash: 241d, last: 241d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-44 INFO: task hung in odev_release 1478 2460d 2482d 0/2 auto-closed as invalid on 2019/02/22 12:59
upstream INFO: task hung in odev_release (3) sound 1 233d 233d 0/28 auto-obsoleted due to no activity on 2024/07/01 05:46
upstream INFO: task hung in odev_release (2) sound 3 767d 836d 0/28 auto-obsoleted due to no activity on 2023/01/17 10:27
upstream INFO: task hung in odev_release sound 5 2050d 2051d 0/28 closed as invalid on 2019/05/08 13:05

Sample crash report:
INFO: task syz-executor.1:6812 blocked for more than 143 seconds.
      Not tainted 5.15.152-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:    0 pid: 6812 ppid:  6095 flags:0x00000005
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6518
 __mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
 odev_release+0x58/0x84 sound/core/seq/oss/seq_oss.c:143
 __fput+0x30c/0x7f0 fs/file_table.c:280
 ____fput+0x20/0x30 fs/file_table.c:308
 task_work_run+0x130/0x1e4 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 do_notify_resume+0x262c/0x32b8 arch/arm64/kernel/signal.c:946
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
 el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
2 locks held by kworker/u4:0/9:
1 lock held by khungtaskd/27:
 #0: ffff800014ae14a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:268
1 lock held by udevd/3583:
 #0: ffff0000cbb83918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12c/0x89c block/bdev.c:817
2 locks held by getty/3718:
 #0: ffff0000d2d77098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001a07e2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:6/4049:
 #0: ffff0000c0021938 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
 #1: ffff80001d127c00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
3 locks held by kworker/u4:6/4073:
3 locks held by kworker/u4:7/4941:
1 lock held by syz-executor.1/6812:
 #0: ffff800016830fc8 (register_mutex#4){+.+.}-{3:3}, at: odev_release+0x58/0x84 sound/core/seq/oss/seq_oss.c:143
2 locks held by syz-executor.1/6813:
1 lock held by syz-executor.1/7020:
1 lock held by syz-executor.1/9445:
1 lock held by syz-executor.0/9483:
2 locks held by syz-executor.4/9504:
 #0: ffff000183e360e0 (&type->s_umount_key#59/1){+.+.}-{3:3}, at: alloc_super+0x1b8/0x844 fs/super.c:229
 #1: ffff800014ae5aa8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffff800014ae5aa8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x660 kernel/rcu/tree_exp.h:845

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


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/24 14:49 linux-5.15.y b95c01af2113 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in odev_release
* Struck through repros no longer work on HEAD.