syzbot


INFO: task hung in acct_process

Status: auto-closed as invalid on 2020/04/26 03:12
Reported-by: syzbot+84b2f2bda1c9e4d273ba@syzkaller.appspotmail.com
First crash: 1984d, last: 1803d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in acct_process kernel 24 1877d 1869d 0/28 auto-closed as invalid on 2020/02/12 06:45

Sample crash report:
team0 (unregistering): Port device team_slave_0 removed
bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves
INFO: task syz-executor.1:14574 blocked for more than 140 seconds.
      Not tainted 4.19.91-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D23592 14574      1 0x80000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 acct_get kernel/acct.c:161 [inline]
 slow_acct_process kernel/acct.c:577 [inline]
 acct_process+0x2e5/0x61e kernel/acct.c:605
 do_exit+0x17ca/0x3080 kernel/exit.c:866
 do_group_exit+0x135/0x370 kernel/exit.c:979
 get_signal+0x3ec/0x1fc0 kernel/signal.c:2578
 do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x41475a
Code: 48 83 c4 20 c3 48 8b 44 24 28 48 8d 50 10 48 89 14 24 48 89 4c 24 08 e8 64 e5 00 00 48 8b 44 24 28 48 89 04 24 e8 56 a6 ff ff <48> 8d 05 ff 92 54 01 48 89 04 24 48 8b 44 24 30 48 89 44 24 08 c7
RSP: 002b:00007ffd9224bcb8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 0000000000eed940 RCX: 000000000041475a
RDX: 0000000040000000 RSI: 00007ffd9224bcf0 RDI: ffffffffffffffff
RBP: 0000000000000152 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd9224bcf0 R14: 0000000000eed99b R15: 00007ffd9224bd00

Showing all locks held in the system:
1 lock held by khungtaskd/1068:
 #0: 00000000a0e70a47 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438
2 locks held by getty/7716:
 #0: 000000003975d693 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000005a74af83 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7717:
 #0: 00000000f2f45102 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000078e5e079 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7718:
 #0: 0000000007557ebc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000004f1e72a4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7719:
 #0: 000000004bb3d936 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000040ac6397 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7720:
 #0: 00000000045211d6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000002cde6a99 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7721:
 #0: 00000000202cf961 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000006290d6d2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8674:
 #0: 0000000099a3c1c1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000007d648281 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
1 lock held by syz-executor.1/14574:
 #0: 000000007a880cca (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline]
 #0: 000000007a880cca (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline]
 #0: 000000007a880cca (&acct->lock#2){+.+.}, at: acct_process+0x2e5/0x61e kernel/acct.c:605
3 locks held by syz-executor.1/17926:
 #0: 000000007a880cca (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline]
 #0: 000000007a880cca (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline]
 #0: 000000007a880cca (&acct->lock#2){+.+.}, at: acct_process+0x2e5/0x61e kernel/acct.c:605
 #1: 00000000ead8eaf1 (sb_writers#4){.+.+}, at: file_start_write_trylock include/linux/fs.h:2782 [inline]
 #1: 00000000ead8eaf1 (sb_writers#4){.+.+}, at: do_acct_process+0xf37/0x1150 kernel/acct.c:517
 #2: 00000000f9d41b11 (&sb->s_type->i_mutex_key#9){++++}, at: inode_trylock include/linux/fs.h:767 [inline]
 #2: 00000000f9d41b11 (&sb->s_type->i_mutex_key#9){++++}, at: ext4_file_write_iter+0x23f/0x1060 fs/ext4/file.c:236

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

NMI backtrace for cpu 0
CPU: 0 PID: 1068 Comm: khungtaskd Not tainted 4.19.91-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+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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:203 [inline]
 watchdog+0x9df/0xee0 kernel/hung_task.c:287
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 17067 Comm: kworker/u4:2 Not tainted 4.19.91-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_tt_purge
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:lockdep_hardirqs_on+0x35d/0x5d0 kernel/locking/lockdep.c:2875
Code: fc ff df 48 89 c1 83 e0 07 48 c1 e9 03 0f b6 14 11 38 c2 7f 08 84 d2 0f 85 87 01 00 00 80 3d 51 38 7a 08 00 0f 85 ba 01 00 00 <65> 48 8b 1c 25 40 ee 01 00 48 8d bb 4c 08 00 00 48 b8 00 00 00 00
RSP: 0018:ffff888027acfb98 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 1ffffffff1399781
RDX: 0000000000000000 RSI: ffffffff81707f0e RDI: 0000000000000000
RBP: ffff888027acfba8 R08: ffff88808c4ea6c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8140635a
R13: ffffffff874c3391 R14: ffffffff8140635a R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 000000008251a000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 trace_hardirqs_on+0x67/0x220 kernel/trace/trace_preemptirq.c:30
 __local_bh_enable_ip+0x15a/0x270 kernel/softirq.c:194
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
 _raw_spin_unlock_bh+0x31/0x40 kernel/locking/spinlock.c:200
 spin_unlock_bh include/linux/spinlock.h:374 [inline]
 batadv_tt_local_purge+0x27a/0x360 net/batman-adv/translation-table.c:1454
 batadv_tt_purge+0x2e/0xa70 net/batman-adv/translation-table.c:3809
 process_one_work+0x989/0x1750 kernel/workqueue.c:2153
 worker_thread+0x98/0xe40 kernel/workqueue.c:2296
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/12/28 03:12 linux-4.19.y 672481c2deff be5c2c81 .config console log report ci2-linux-4-19
2019/10/05 02:43 linux-4.19.y 555161ee1b7a f3f7d9c8 .config console log report ci2-linux-4-19
2019/10/03 10:13 linux-4.19.y 555161ee1b7a fc17ba49 .config console log report ci2-linux-4-19
2019/10/02 10:41 linux-4.19.y 555161ee1b7a 2e29b534 .config console log report ci2-linux-4-19
2019/06/29 19:32 linux-4.19.y aec3002d07fd 7509bf36 .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.