syzbot


INFO: task can't die in mark_held_locks (2)

Status: auto-closed as invalid on 2022/04/10 14:18
Reported-by: syzbot+88392dd280b06d8f0357@syzkaller.appspotmail.com
First crash: 241d, last: 179d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task can't die in mark_held_locks 1 343d 338d 0/23 auto-closed as invalid on 2021/10/28 15:59

Sample crash report:
INFO: task syz-executor.3:26970 can't die for more than 143 seconds.
task:syz-executor.3  state:R  running task     stack:27776 pid:26970 ppid:  3629 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5000 [inline]
 __schedule+0xab2/0x4db0 kernel/sched/core.c:6309
 mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4206
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6463
2 locks held by getty/3278:
 #0: ffff88807f370098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
 #1: ffffc90002b662e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077
1 lock held by syz-executor.3/26970:

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

Kernel panic - not syncing: hung_task: blocked tasks
CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.17.0-rc2-next-20220204-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 panic+0x2b0/0x605 kernel/panic.c:237
 check_hung_uninterruptible_tasks kernel/hung_task.c:260 [inline]
 watchdog.cold+0x1ca/0x1de kernel/hung_task.c:413
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-linux-next-kasan-gce-root 2022/02/09 14:18 linux-next ef6b35306dd8 0b33604d .config log report info INFO: task can't die in mark_held_locks
ci-upstream-linux-next-kasan-gce-root 2022/01/30 16:26 linux-next b605fdc54c2b 495e00c5 .config log report info INFO: task can't die in mark_held_locks
ci-upstream-linux-next-kasan-gce-root 2021/12/09 13:22 linux-next 4eee8d0b64ec b54aa474 .config log report info INFO: task can't die in mark_held_locks