syzbot


INFO: rcu detected stall in __skb_try_recv_datagram

Status: auto-closed as invalid on 2019/02/22 10:34
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+c25dc25aa75ed3b7495b@syzkaller.appspotmail.com
First crash: 2059d, last: 2059d

Sample crash report:
INFO: rcu_sched detected stalls on CPUs/tasks:
	(detected by 1, t=105148 jiffies, g=10867, c=10866, q=812)
All QSes seen, last rcu_sched kthread activity 105185 (4294868890-4294763705), jiffies_till_next_fqs=3, root ->qsmask 0x0
syz-executor3   R  running task    25408  6753   4489 0x00000008
Call Trace:
 <IRQ>
 sched_show_task.cold.84+0x27a/0x301 kernel/sched/core.c:5324
 print_other_cpu_stall.cold.77+0x92f/0x9d2 kernel/rcu/tree.c:1441
 check_cpu_stall.isra.60+0x721/0xf70 kernel/rcu/tree.c:1559
 __rcu_pending kernel/rcu/tree.c:3244 [inline]
 rcu_pending kernel/rcu/tree.c:3291 [inline]
 rcu_check_callbacks+0x23f/0xcd0 kernel/rcu/tree.c:2646
 update_process_times+0x2d/0x70 kernel/time/timer.c:1636
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x3eb/0x10c0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1028 [inline]
 smp_apic_timer_interrupt+0x165/0x730 arch/x86/kernel/apic/apic.c:1053
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184
Code: a8 b0 f1 87 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 21 48 83 3d be a2 46 01 00 74 0e 48 89 df 57 9d <0f> 1f 44 00 00 eb bb 0f 0b 0f 0b e8 9f e6 0e fb eb 97 e8 98 e6 0e 
RSP: 0018:ffff8801961ef528 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 0000000000000282 RCX: 1ffff10036566d1b
RDX: 1ffffffff0fe3615 RSI: 0000000000000000 RDI: 0000000000000282
RBP: ffff8801961ef538 R08: ffff8801b2b368b8 R09: 0000000000000006
R10: ffff8801b2b36080 R11: 0000000000000000 R12: ffff8801ad7368e0
R13: ffff8801961ef660 R14: 0000000000000000 R15: 0000000000000282
 spin_unlock_irqrestore include/linux/spinlock.h:365 [inline]
 __skb_try_recv_datagram+0x236/0x5a0 net/core/datagram.c:272
 unix_dgram_recvmsg+0x2f1/0x1bb0 net/unix/af_unix.c:2098
 sock_recvmsg_nosec net/socket.c:815 [inline]
 sock_recvmsg+0xd0/0x110 net/socket.c:822
 __sys_recvfrom+0x311/0x5d0 net/socket.c:1855
 __do_sys_recvfrom net/socket.c:1873 [inline]
 __se_sys_recvfrom net/socket.c:1869 [inline]
 __x64_sys_recvfrom+0xe1/0x1a0 net/socket.c:1869
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456cb9
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007f95d4d21c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
RAX: ffffffffffffffda RBX: 00007f95d4d226d4 RCX: 0000000000456cb9
RDX: 00000000000000ae RSI: 0000000020000080 RDI: 0000000000000015
RBP: 00000000009300a0 R08: 0000000020000140 R09: 0000000000703000
R10: fffffffffffffffe R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d2e50 R14: 00000000004c7e4c R15: 0000000000000000
rcu_sched kthread starved for 107426 jiffies! g10867 c10866 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1
RCU grace-period kthread stack dump:
rcu_sched       R  running task    23688    10      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_timeout+0x140/0x260 kernel/time/timer.c:1801
 rcu_gp_kthread+0x717/0x1c90 kernel/rcu/tree.c:2179
 kthread+0x345/0x410 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/08/07 19:19 net-old 4576cd469d98 1beb8136 .config console log report ci-upstream-net-this-kasan-gce
* Struck through repros no longer work on HEAD.