syzbot


INFO: task hung in ppp_release

Status: auto-closed as invalid on 2020/08/28 19:07
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 847d, last: 847d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in ppp_release (2) 1 376d 376d 0/24 auto-closed as invalid on 2021/12/13 06:07
android-49 INFO: task hung in ppp_release 1 1263d 1260d 0/3 auto-closed as invalid on 2019/10/08 10:46

Sample crash report:
INFO: task syz-executor.4:30500 blocked for more than 143 seconds.
      Not tainted 5.7.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28120 30500   7408 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3367 [inline]
 __schedule+0x937/0x1ff0 kernel/sched/core.c:4083
 schedule+0xd0/0x2a0 kernel/sched/core.c:4158
 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x16a/0x270 kernel/sched/completion.c:138
 __flush_work+0x4fd/0xa80 kernel/workqueue.c:3045
 flush_all_backlogs net/core/dev.c:5537 [inline]
 rollback_registered_many+0x562/0xe70 net/core/dev.c:8823
 rollback_registered+0xf2/0x1c0 net/core/dev.c:8883
 unregister_netdevice_queue net/core/dev.c:9981 [inline]
 unregister_netdevice_queue+0x1d7/0x2b0 net/core/dev.c:9974
 unregister_netdevice include/linux/netdevice.h:2725 [inline]
 ppp_release+0x216/0x240 drivers/net/ppp/ppp_generic.c:403
 __fput+0x33e/0x880 fs/file_table.c:280
 task_work_run+0xf4/0x1b0 kernel/task_work.c:123
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x416661
Code: Bad RIP value.
RSP: 002b:00007ffe9140d3e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000416661
RDX: 0000000000000000 RSI: 0000000000001a4a RDI: 0000000000000006
RBP: 0000000000000001 R08: 00000000ab129a4a R09: 00000000ab129a4e
R10: 00007ffe9140d4d0 R11: 0000000000000293 R12: 0000000000791430
R13: 0000000000143658 R14: ffffffffffffffff R15: 000000000078bf0c

Showing all locks held in the system:
3 locks held by kworker/u4:1/21:
3 locks held by kworker/1:1/39:
 #0: ffff888215386538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:226 [inline]
 #0: ffff888215386538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888215386538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
 #0: ffff888215386538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
 #0: ffff888215386538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline]
 #0: ffff888215386538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline]
 #0: ffff888215386538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239
 #1: ffffc90000ec7dc0 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243
 #2: ffffffff8a586988 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4584
3 locks held by kworker/u4:5/244:
1 lock held by khungtaskd/1144:
 #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754
1 lock held by systemd-udevd/4120:
1 lock held by in:imklog/6838:
 #0: ffff888095d4f6b0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826
2 locks held by systemd-udevd/18734:
 #0: ffff888098e3e450 (sb_writers#7){.+.+}-{0:0}, at: sb_start_write include/linux/fs.h:1655 [inline]
 #0: ffff888098e3e450 (sb_writers#7){.+.+}-{0:0}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:354
 #1: ffff8880ae722ec8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x304/0x410 kernel/sched/psi.c:817
1 lock held by systemd-udevd/18762:
1 lock held by systemd-udevd/18813:
3 locks held by systemd-udevd/18818:
2 locks held by systemd-udevd/18819:
3 locks held by systemd-udevd/18854:
1 lock held by systemd-udevd/18890:
2 locks held by systemd-udevd/18905:
1 lock held by systemd-udevd/20644:
1 lock held by systemd-udevd/20645:
2 locks held by syz-executor.4/30500:
 #0: ffffffff8a586988 (rtnl_mutex){+.+.}-{3:3}, at: ppp_release+0x178/0x240 drivers/net/ppp/ppp_generic.c:401
 #1: ffffffff89979a70 (cpu_hotplug_lock){++++}-{0:0}, at: get_online_cpus include/linux/cpu.h:143 [inline]
 #1: ffffffff89979a70 (cpu_hotplug_lock){++++}-{0:0}, at: flush_all_backlogs net/core/dev.c:5530 [inline]
 #1: ffffffff89979a70 (cpu_hotplug_lock){++++}-{0:0}, at: rollback_registered_many+0x45b/0xe70 net/core/dev.c:8823

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

NMI backtrace for cpu 1
CPU: 1 PID: 1144 Comm: khungtaskd Not tainted 5.7.0-rc7-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+0x188/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xa8c/0x1010 kernel/hung_task.c:289
 kthread+0x388/0x470 kernel/kthread.c:268
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 30385 Comm: syz-executor.3 Not tainted 5.7.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:is_idle_task include/linux/sched.h:1642 [inline]
RIP: 0010:___might_sleep+0x18b/0x2b0 kernel/sched/core.c:6769
Code: ff ff 65 4c 8b 2c 25 00 1f 02 00 49 8d 7d 24 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 <83> c0 03 38 d0 7c 08 84 d2 0f 85 08 01 00 00 41 f6 45 24 02 0f 85
RSP: 0018:ffffc90007d7fdb8 EFLAGS: 00000202
RAX: 0000000000000004 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 1ffff11007ddbd78 RDI: ffff88803eede324
RBP: ffffffff8837bc80 R08: 0000000000000001 R09: ffffed1014dc1e61
R10: ffff8880a6e0f307 R11: ffffed1014dc1e60 R12: 0000000000001c9b
R13: ffff88803eede300 R14: ffff88803eede300 R15: ffffffff81d52a50
FS:  0000000001530940(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004d8b90 CR3: 000000009f96b000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 io_ring_ctx_wait_and_kill+0xa9/0x5f0 fs/io_uring.c:7323
 io_uring_release+0x3e/0x50 fs/io_uring.c:7345
 __fput+0x33e/0x880 fs/file_table.c:280
 task_work_run+0xf4/0x1b0 kernel/task_work.c:123
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x416661
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fff85adaa70 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000416661
RDX: 0000000000000000 RSI: 000000000000085e RDI: 0000000000000005
RBP: 0000000000000001 R08: 000000006c5ae85e R09: 000000006c5ae862
R10: 00007fff85adab60 R11: 0000000000000293 R12: 000000000078c900
R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078bfac

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2020/05/30 19:03 upstream 86852175b016 6f3e1c7c .config log report
* Struck through repros no longer work on HEAD.