INFO: rcu detected stall in inet_dgram_connect

From: syzbot
Date: Sun Dec 30 2018 - 22:34:19 EST

Hello,

syzbot found the following crash on:

HEAD commit: f7d18ef6a95f Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=152cb86f400000
kernel config: https://syzkaller.appspot.com/x/.config?x=4b137b8ba637eb77
dashboard link: https://syzkaller.appspot.com/bug?extid=94683b47a87718b5dff7
compiler: gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+94683b47a87718b5dff7@xxxxxxxxxxxxxxxxxxxxxxxxx

netlink: 8 bytes leftover after parsing attributes in process `syz-executor4'.
netlink: 8 bytes leftover after parsing attributes in process `syz-executor4'.
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P23939
rcu: (detected by 1, t=10503 jiffies, g=56797, q=1404)
syz-executor5 R running task 24952 23939 8064 0x00000006
Call Trace:
<IRQ>
sched_show_task.cold.86+0x2b6/0x30a kernel/sched/core.c:5293
rcu_print_detail_task_stall_rnp+0xc7/0x103 kernel/rcu/tree_plugin.h:690
rcu_print_detail_task_stall kernel/rcu/tree_plugin.h:703 [inline]
print_other_cpu_stall.cold.69+0x5b5/0x8db kernel/rcu/tree.c:1289
check_cpu_stall kernel/rcu/tree.c:1429 [inline]
rcu_pending kernel/rcu/tree.c:3018 [inline]
rcu_check_callbacks+0xfe8/0x1410 kernel/rcu/tree.c:2521
update_process_times+0x2d/0x70 kernel/time/timer.c:1635
tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:161
tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1271
__run_hrtimer kernel/time/hrtimer.c:1389 [inline]
__hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1451
hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1509
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1060
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
</IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:94
Code: 14 dd 28 00 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d c3 66 90 <55> 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 c8 47
RSP: 0018:ffff888065fa7458 EFLAGS: 00000217 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff86c5ddd8
RDX: 00000000ffffffff RSI: 000000000000227d RDI: 0000000000000004
RBP: ffff888065fa7718 R08: ffff8880a9eac700 R09: 0000000000000000
R10: 0000000000000000 R11: ffff8880a9eac700 R12: 000000000000227d
R13: dffffc0000000000 R14: ffff8880a86c8dc0 R15: 00000000ffffffff
xfrm_policy_lookup+0x7e/0x80 net/xfrm/xfrm_policy.c:2145
xfrm_bundle_lookup net/xfrm/xfrm_policy.c:2939 [inline]
xfrm_lookup_with_ifid+0x972/0x2b80 net/xfrm/xfrm_policy.c:3080
xfrm_lookup net/xfrm/xfrm_policy.c:3172 [inline]
xfrm_lookup_route+0x3c/0x1f0 net/xfrm/xfrm_policy.c:3183
ip_route_output_flow+0xb1/0xc0 net/ipv4/route.c:2582
ip_route_connect include/net/route.h:309 [inline]
__ip4_datagram_connect+0x70e/0x1330 net/ipv4/datagram.c:51
ip4_datagram_connect+0x2f/0x50 net/ipv4/datagram.c:92
inet_dgram_connect+0x154/0x2e0 net/ipv4/af_inet.c:571
__sys_connect+0x37d/0x4c0 net/socket.c:1664
__do_sys_connect net/socket.c:1675 [inline]
__se_sys_connect net/socket.c:1672 [inline]
__x64_sys_connect+0x73/0xb0 net/socket.c:1672
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457ec9
Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fee7c44bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9
RDX: 0000000000000010 RSI: 0000000020593000 RDI: 0000000000000004
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fee7c44c6d4
R13: 00000000004be2ff R14: 00000000004ce440 R15: 00000000ffffffff
syz-executor5 R running task 24952 23939 8064 0x8000000e
Call Trace:
<IRQ>
sched_show_task.cold.86+0x2b6/0x30a kernel/sched/core.c:5293
rcu_print_detail_task_stall_rnp+0xc7/0x103 kernel/rcu/tree_plugin.h:690
rcu_print_detail_task_stall kernel/rcu/tree_plugin.h:705 [inline]
print_other_cpu_stall.cold.69+0x615/0x8db kernel/rcu/tree.c:1289
check_cpu_stall kernel/rcu/tree.c:1429 [inline]
rcu_pending kernel/rcu/tree.c:3018 [inline]
rcu_check_callbacks+0xfe8/0x1410 kernel/rcu/tree.c:2521
update_process_times+0x2d/0x70 kernel/time/timer.c:1635
tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:161
tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1271
__run_hrtimer kernel/time/hrtimer.c:1389 [inline]
__hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1451
hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1509
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1060
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
</IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:94
Code: 14 dd 28 00 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d c3 66 90 <55> 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 c8 47
RSP: 0018:ffff888065fa7458 EFLAGS: 00000217 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff86c5ddd8
RDX: 00000000ffffffff RSI: 000000000000227d RDI: 0000000000000004
RBP: ffff888065fa7718 R08: ffff8880a9eac700 R09: 0000000000000000
R10: 0000000000000000 R11: ffff8880a9eac700 R12: 000000000000227d
R13: dffffc0000000000 R14: ffff8880a86c8dc0 R15: 00000000ffffffff
xfrm_policy_lookup+0x7e/0x80 net/xfrm/xfrm_policy.c:2145
xfrm_bundle_lookup net/xfrm/xfrm_policy.c:2939 [inline]
xfrm_lookup_with_ifid+0x972/0x2b80 net/xfrm/xfrm_policy.c:3080
xfrm_lookup net/xfrm/xfrm_policy.c:3172 [inline]
xfrm_lookup_route+0x3c/0x1f0 net/xfrm/xfrm_policy.c:3183
ip_route_output_flow+0xb1/0xc0 net/ipv4/route.c:2582
ip_route_connect include/net/route.h:309 [inline]
__ip4_datagram_connect+0x70e/0x1330 net/ipv4/datagram.c:51
ip4_datagram_connect+0x2f/0x50 net/ipv4/datagram.c:92
inet_dgram_connect+0x154/0x2e0 net/ipv4/af_inet.c:571
__sys_connect+0x37d/0x4c0 net/socket.c:1664
__do_sys_connect net/socket.c:1675 [inline]
__se_sys_connect net/socket.c:1672 [inline]
__x64_sys_connect+0x73/0xb0 net/socket.c:1672
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457ec9
Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fee7c44bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9
RDX: 0000000000000010 RSI: 0000000020593000 RDI: 0000000000000004
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fee7c44c6d4
R13: 00000000004be2ff R14: 00000000004ce440 R15: 00000000ffffffff
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { P23939 } 10898 jiffies s: 5085 root: 0x0/T
rcu: blocking rcu_node structures:


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