INFO: rcu detected stall in inet_sendmsg

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syzbot

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May 24, 2019, 7:15:05 PM5/24/19
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Hello,

syzbot found the following crash on:

HEAD commit: bbcb3c09 Linux 4.14.121
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16cc39bca00000
kernel config: https://syzkaller.appspot.com/x/.config?x=2a2cb26ecd414213
dashboard link: https://syzkaller.appspot.com/bug?extid=a8033fbb1f13b4f6bb8c
compiler: gcc (GCC) 9.0.0 20181231 (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+a8033f...@syzkaller.appspotmail.com

INFO: rcu_preempt self-detected stall on CPU
1-...: (10499 ticks this GP) idle=bc6/140000000000001/0
softirq=19225/19225 fqs=0
(t=10500 jiffies g=4769 c=4768 q=69)
rcu_preempt kthread starved for 10500 jiffies! g4769 c4768 f0x0
RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=0
rcu_preempt I29776 8 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2807 [inline]
__schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383
schedule+0x92/0x1c0 kernel/sched/core.c:3427
schedule_timeout+0x43e/0xe10 kernel/time/timer.c:1744
rcu_gp_kthread+0xbf4/0x1ec0 kernel/rcu/tree.c:2255
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
NMI backtrace for cpu 1
CPU: 1 PID: 8905 Comm: syz-executor.0 Not tainted 4.14.121 #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x138/0x19c lib/dump_stack.c:53
nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline]
rcu_dump_cpu_stacks+0x186/0x1d2 kernel/rcu/tree.c:1396
print_cpu_stall kernel/rcu/tree.c:1542 [inline]
check_cpu_stall kernel/rcu/tree.c:1610 [inline]
__rcu_pending kernel/rcu/tree.c:3390 [inline]
rcu_pending kernel/rcu/tree.c:3452 [inline]
rcu_check_callbacks.cold+0x43d/0xd0a kernel/rcu/tree.c:2792
update_process_times+0x31/0x70 kernel/time/timer.c:1588
tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:161
tick_sched_timer+0x43/0x130 kernel/time/tick-sched.c:1219
__run_hrtimer kernel/time/hrtimer.c:1220 [inline]
__hrtimer_run_queues+0x270/0xbc0 kernel/time/hrtimer.c:1284
hrtimer_interrupt+0x1d8/0x5d0 kernel/time/hrtimer.c:1318
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline]
smp_apic_timer_interrupt+0x11c/0x5e0 arch/x86/kernel/apic/apic.c:1062
apic_timer_interrupt+0x8e/0xa0 arch/x86/entry/entry_64.S:789
</IRQ>
RIP: 0010:__read_seqcount_begin include/linux/seqlock.h:114 [inline]
RIP: 0010:raw_read_seqcount_begin include/linux/seqlock.h:148 [inline]
RIP: 0010:read_seqcount_begin include/linux/seqlock.h:165 [inline]
RIP: 0010:xfrm_state_find+0x1249/0x28a0 net/xfrm/xfrm_state.c:950
RSP: 0018:ffff888085cdefb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000015 RBX: 0000000000000212 RCX: ffffc9000803e000
RDX: 0000000000040000 RSI: ffffffff854122d1 RDI: 0000000000000212
RBP: ffff888085cdf138 R08: ffff88808d1826c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880a8971d38
xfrm_tmpl_resolve_one+0x1b0/0x7f0 net/xfrm/xfrm_policy.c:1394
xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:1438 [inline]
xfrm_resolve_and_create_bundle+0x219/0x2480 net/xfrm/xfrm_policy.c:1832
xfrm_lookup+0x212/0x1920 net/xfrm/xfrm_policy.c:2164
xfrm_lookup_route+0x38/0x1b0 net/xfrm/xfrm_policy.c:2284
ip_route_output_flow+0x90/0xa0 net/ipv4/route.c:2599
udp_sendmsg+0x14a1/0x1da0 net/ipv4/udp.c:1021
udpv6_sendmsg+0x1356/0x2640 net/ipv6/udp.c:1193
inet_sendmsg+0x122/0x500 net/ipv4/af_inet.c:762
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xce/0x110 net/socket.c:656
___sys_sendmsg+0x349/0x840 net/socket.c:2062
__sys_sendmmsg+0x152/0x3a0 net/socket.c:2152
SYSC_sendmmsg net/socket.c:2183 [inline]
SyS_sendmmsg+0x35/0x60 net/socket.c:2178
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459279
RSP: 002b:00007f67cad8fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459279
RDX: 040000000000029a RSI: 0000000020000180 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f67cad906d4
R13: 00000000004c65fc R14: 00000000004db280 R15: 00000000ffffffff
INFO: rcu_sched detected stalls on CPUs/tasks:
1-...: (10500 ticks this GP) idle=bc6/140000000000000/0
softirq=19225/19225 fqs=0
(detected by 0, t=10557 jiffies, g=2849, c=2848, q=4)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8905 Comm: syz-executor.0 Not tainted 4.14.121 #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
task: ffff88808d1826c0 task.stack: ffff888085cd8000
RIP: 0010:__read_once_size include/linux/compiler.h:186 [inline]
RIP: 0010:__read_seqcount_begin include/linux/seqlock.h:113 [inline]
RIP: 0010:raw_read_seqcount_begin include/linux/seqlock.h:148 [inline]
RIP: 0010:read_seqcount_begin include/linux/seqlock.h:165 [inline]
RIP: 0010:xfrm_state_find+0x1243/0x28a0 net/xfrm/xfrm_state.c:950
RSP: 0018:ffff888085cdefb8 EFLAGS: 00000246
RAX: 0000000000040000 RBX: 0000000000000212 RCX: ffffc9000803e000
RDX: 0000000000040000 RSI: ffffffff854122d1 RDI: 0000000000000212
RBP: ffff888085cdf138 R08: ffff88808d1826c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880a8971d38
FS: 00007f67cad90700(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f911ebb3c50 CR3: 00000000a4e6b000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
xfrm_tmpl_resolve_one+0x1b0/0x7f0 net/xfrm/xfrm_policy.c:1394
xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:1438 [inline]
xfrm_resolve_and_create_bundle+0x219/0x2480 net/xfrm/xfrm_policy.c:1832
xfrm_lookup+0x212/0x1920 net/xfrm/xfrm_policy.c:2164
xfrm_lookup_route+0x38/0x1b0 net/xfrm/xfrm_policy.c:2284
ip_route_output_flow+0x90/0xa0 net/ipv4/route.c:2599
udp_sendmsg+0x14a1/0x1da0 net/ipv4/udp.c:1021
udpv6_sendmsg+0x1356/0x2640 net/ipv6/udp.c:1193
inet_sendmsg+0x122/0x500 net/ipv4/af_inet.c:762
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xce/0x110 net/socket.c:656
___sys_sendmsg+0x349/0x840 net/socket.c:2062
__sys_sendmmsg+0x152/0x3a0 net/socket.c:2152
SYSC_sendmmsg net/socket.c:2183 [inline]
SyS_sendmmsg+0x35/0x60 net/socket.c:2178
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459279
RSP: 002b:00007f67cad8fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459279
RDX: 040000000000029a RSI: 0000000020000180 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f67cad906d4
R13: 00000000004c65fc R14: 00000000004db280 R15: 00000000ffffffff
Code: e8 d3 80 1b fc 85 db 41 bc f5 ff ff ff 0f 85 e9 00 00 00 e8 c0 80 1b
fc 44 8b a5 68 ff ff ff e9 d8 00 00 00 e8 af 80 1b fc f3 90 <8b> 05 47 76
e5 02 a8 01 75 ef 89 85 f0 fe ff ff e9 66 f0 ff ff
rcu_sched kthread starved for 10557 jiffies! g2849 c2848 f0x0
RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=0
rcu_sched I29824 9 2 0x80000000
Call Trace:
context_switch kernel/sched/core.c:2807 [inline]
__schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383
schedule+0x92/0x1c0 kernel/sched/core.c:3427
schedule_timeout+0x43e/0xe10 kernel/time/timer.c:1744
rcu_gp_kthread+0xbf4/0x1ec0 kernel/rcu/tree.c:2255
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404


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syzbot

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Jan 6, 2020, 9:34:06 AM1/6/20
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
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