INFO: rcu detected stall in sctp_inet_connect

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 3fc89857 Linux 4.19.128
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=109583c1100000
kernel config: https://syzkaller.appspot.com/x/.config?x=6c6e6bf14f2aabf
dashboard link: https://syzkaller.appspot.com/bug?extid=9055972a8fe05f2401c4
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+905597...@syzkaller.appspotmail.com

EXT4-fs: failed to create workqueue
EXT4-fs (loop1): mount failed
netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'.
netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'.
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P28522
rcu: (detected by 0, t=10503 jiffies, g=628049, q=3572)
syz-executor.4 R running task 28912 28522 6858 0x00000006
Call Trace:
<IRQ>
sched_show_task.cold+0x334/0x395 kernel/sched/core.c:5338
rcu_print_detail_task_stall_rnp+0xe7/0x120 kernel/rcu/tree_plugin.h:627
rcu_print_detail_task_stall kernel/rcu/tree_plugin.h:640 [inline]
print_other_cpu_stall kernel/rcu/tree.c:1418 [inline]
check_cpu_stall kernel/rcu/tree.c:1557 [inline]
__rcu_pending kernel/rcu/tree.c:3293 [inline]
rcu_pending kernel/rcu/tree.c:3336 [inline]
rcu_check_callbacks.cold+0x84a/0xddc kernel/rcu/tree.c:2682
update_process_times+0x2a/0x70 kernel/time/timer.c:1638
tick_sched_handle.isra.0+0x91/0x180 kernel/time/tick-sched.c:168
tick_sched_timer+0x44/0x130 kernel/time/tick-sched.c:1278
__run_hrtimer kernel/time/hrtimer.c:1401 [inline]
__hrtimer_run_queues+0x2ec/0xd20 kernel/time/hrtimer.c:1463
hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1521
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
</IRQ>
RIP: 0010:sctp_bind_addr_state+0x11f/0x330 net/sctp/bind_addr.c:391
Code: 67 02 cc fa 48 8d 7b 3d 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 c6 01 00 00 44 0f b6 7b 3d <31> ff 44 89 fe e8 67 03 cc fa 45 84 ff 74 32 e8 2d 02 cc fa 48 8b
RSP: 0018:ffff8881969dfa68 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff888196a85e00 RCX: ffffc9000e406000
RDX: 0000000000000005 RSI: ffffffff869b9859 RDI: ffff888196a85e3d
RBP: dffffc0000000000 R08: ffff88819450c1c0 R09: ffffed1015cc473b
R10: ffffed1015cc473a R11: ffff8880ae6239d3 R12: ffff8881969dfb00
R13: ffff8881af0f6990 R14: ffffffff897853a0 R15: 0000000000000001
sctp_copy_local_addr_list+0x255/0x530 net/sctp/protocol.c:176
sctp_copy_one_addr+0x5b/0x170 net/sctp/bind_addr.c:449
sctp_bind_addr_copy+0xfc/0x2ca net/sctp/bind_addr.c:71
__sctp_connect+0x74e/0xcc0 net/sctp/socket.c:1214
sctp_connect net/sctp/socket.c:4520 [inline]
sctp_inet_connect+0x14b/0x1b0 net/sctp/socket.c:4535
__sys_connect+0x238/0x2c0 net/socket.c:1663
__do_sys_connect net/socket.c:1674 [inline]
__se_sys_connect net/socket.c:1671 [inline]
__x64_sys_connect+0x6f/0xb0 net/socket.c:1671
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45ca69
Code: 0d 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fa43d4efc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00000000004db440 RCX: 000000000045ca69
RDX: 000000000000001c RSI: 0000000020000080 RDI: 0000000000000006
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000089 R14: 00000000004c3476 R15: 00007fa43d4f06d4
syz-executor.4 R running task 28912 28522 6858 0x80000006
Call Trace:
<IRQ>
sched_show_task.cold+0x334/0x395 kernel/sched/core.c:5338
rcu_print_detail_task_stall_rnp+0xe7/0x120 kernel/rcu/tree_plugin.h:627
rcu_print_detail_task_stall kernel/rcu/tree_plugin.h:642 [inline]
print_other_cpu_stall kernel/rcu/tree.c:1418 [inline]
check_cpu_stall kernel/rcu/tree.c:1557 [inline]
__rcu_pending kernel/rcu/tree.c:3293 [inline]
rcu_pending kernel/rcu/tree.c:3336 [inline]
rcu_check_callbacks.cold+0x8a8/0xddc kernel/rcu/tree.c:2682
update_process_times+0x2a/0x70 kernel/time/timer.c:1638
tick_sched_handle.isra.0+0x91/0x180 kernel/time/tick-sched.c:168
tick_sched_timer+0x44/0x130 kernel/time/tick-sched.c:1278
__run_hrtimer kernel/time/hrtimer.c:1401 [inline]
__hrtimer_run_queues+0x2ec/0xd20 kernel/time/hrtimer.c:1463
hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1521
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
</IRQ>
RIP: 0010:sctp_bind_addr_state+0x11f/0x330 net/sctp/bind_addr.c:391
Code: 67 02 cc fa 48 8d 7b 3d 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 c6 01 00 00 44 0f b6 7b 3d <31> ff 44 89 fe e8 67 03 cc fa 45 84 ff 74 32 e8 2d 02 cc fa 48 8b
RSP: 0018:ffff8881969dfa68 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff888196a85e00 RCX: ffffc9000e406000
RDX: 0000000000000005 RSI: ffffffff869b9859 RDI: ffff888196a85e3d
RBP: dffffc0000000000 R08: ffff88819450c1c0 R09: ffffed1015cc473b
R10: ffffed1015cc473a R11: ffff8880ae6239d3 R12: ffff8881969dfb00
R13: ffff8881af0f6990 R14: ffffffff897853a0 R15: 0000000000000001
sctp_copy_local_addr_list+0x255/0x530 net/sctp/protocol.c:176
sctp_copy_one_addr+0x5b/0x170 net/sctp/bind_addr.c:449
sctp_bind_addr_copy+0xfc/0x2ca net/sctp/bind_addr.c:71
__sctp_connect+0x74e/0xcc0 net/sctp/socket.c:1214
sctp_connect net/sctp/socket.c:4520 [inline]
sctp_inet_connect+0x14b/0x1b0 net/sctp/socket.c:4535
__sys_connect+0x238/0x2c0 net/socket.c:1663
__do_sys_connect net/socket.c:1674 [inline]
__se_sys_connect net/socket.c:1671 [inline]
__x64_sys_connect+0x6f/0xb0 net/socket.c:1671
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45ca69
Code: 0d 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fa43d4efc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00000000004db440 RCX: 000000000045ca69
RDX: 000000000000001c RSI: 0000000020000080 RDI: 0000000000000006
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000089 R14: 00000000004c3476 R15: 00007fa43d4f06d4
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { P28694 P28522 } 10732 jiffies s: 18733 root: 0x0/T
rcu: blocking rcu_node structures:


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.