syzbot


INFO: task hung in raw_release

Status: auto-closed as invalid on 2020/09/30 10:18
Reported-by: syzbot+6c0fae36e3ead9d0ec2c@syzkaller.appspotmail.com
First crash: 1422d, last: 1422d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in raw_release can 1388 1031d 1569d 0/26 closed as dup on 2021/06/26 09:46
linux-4.19 INFO: task hung in raw_release (2) syz error 4 1107d 1212d 0/1 upstream: reported syz repro on 2020/12/29 11:35

Sample crash report:
IPVS: ftp: loaded support on port[0] = 21
INFO: task syz-executor.2:1172 blocked for more than 140 seconds.
      Not tainted 4.19.125-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28640  1172   6710 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
 rwsem_down_write_failed+0x3d4/0x7a0 kernel/locking/rwsem-xadd.c:618
 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117
 __down_write arch/x86/include/asm/rwsem.h:142 [inline]
 down_write+0x4f/0x90 kernel/locking/rwsem.c:72
 unregister_netdevice_notifier+0x75/0x320 net/core/dev.c:1712
 raw_release+0x53/0x6c0 net/can/raw.c:358
 __sock_release+0xcd/0x2a0 net/socket.c:579
 sock_close+0x15/0x20 net/socket.c:1140
 __fput+0x2cd/0x890 fs/file_table.c:278
 task_work_run+0x13f/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416661
Code: Bad RIP value.
RSP: 002b:00007fffc255ae50 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416661
RDX: 0000001b31b20000 RSI: 0000000000000593 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00000000fa3e2593 R09: 00000000fa3e2597
R10: 00007fffc255af40 R11: 0000000000000293 R12: 000000000078c900
R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078bfac

Showing all locks held in the system:
1 lock held by khungtaskd/1081:
 #0: 00000000d909cda4 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440
1 lock held by systemd-journal/3683:
3 locks held by in:imklog/6140:
 #0: 0000000030cdf26f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767
 #1: 000000008bc471f1 (remove_cache_srcu){....}, at: quarantine_reduce+0x60/0x1a0 mm/kasan/quarantine.c:261
 #2: 00000000d909cda4 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline]
 #2: 00000000d909cda4 (rcu_read_lock){....}, at: update_curr+0x2c3/0x870 kernel/sched/fair.c:857
2 locks held by agetty/6270:
 #0: 00000000b42be1b1 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
 #1: 00000000fa581887 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154
3 locks held by kworker/u4:7/15115:
 #0: 000000004f35fecf (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1823 [inline]
 #0: 000000004f35fecf (&rq->lock){-.-.}, at: __schedule+0x1f9/0x1fc0 kernel/sched/core.c:3453
 #1: 00000000d909cda4 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline]
 #1: 00000000d909cda4 (rcu_read_lock){....}, at: update_curr+0x2c3/0x870 kernel/sched/fair.c:857
 #2: 000000001ec46767 (&base->lock){-.-.}, at: lock_timer_base+0x55/0x1a0 kernel/time/timer.c:938
2 locks held by agetty/24599:
 #0: 00000000adee60d7 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
 #1: 000000008677ad91 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154
2 locks held by syz-executor.2/1172:
 #0: 00000000f9efa30b (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline]
 #0: 00000000f9efa30b (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:578
 #1: 0000000035bdac1f (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x75/0x320 net/core/dev.c:1712
3 locks held by syz-executor.2/1177:

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

NMI backtrace for cpu 1
CPU: 1 PID: 1081 Comm: khungtaskd Not tainted 4.19.125-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+0x1fc/0x2fe lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x962/0xe40 kernel/hung_task.c:287
 kthread+0x30b/0x410 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3683 Comm: systemd-journal Not tainted 4.19.125-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:___bpf_prog_run+0x26db/0x5050 kernel/bpf/core.c:1239
Code: b6 04 18 38 d0 7f 08 84 c0 0f 85 61 1c 00 00 41 0f b6 46 01 48 89 c2 83 e2 0f 4c 8d 7c d5 00 4c 89 fa 48 c1 ea 03 80 3c 1a 00 <0f> 85 cf 23 00 00 c0 e8 04 49 8b 17 0f b6 c0 4c 8d 7c c5 00 4c 89
RSP: 0018:ffff8880946afa30 EFLAGS: 00000246
RAX: 0000000000000020 RBX: dffffc0000000000 RCX: ffff8880946afe70
RDX: 1ffff110128d5f60 RSI: ffffffff81714acf RDI: ffffc9000193f061
RBP: ffff8880946afb00 R08: ffff8880946a4040 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff876fdfc0
R13: ffffed10128d5f62 R14: ffffc9000193f060 R15: ffff8880946afb00
FS:  00007f204464d8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2040115000 CR3: 00000000944fd000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/02 10:17 linux-4.19.y 2d16cf4817bc a0331e89 .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.