BUG: unable to handle kernel paging request in __enqueue_entity

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: ce28bb445388 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1185e8c3400000
kernel config: https://syzkaller.appspot.com/x/.config?x=67a2081147a23142
dashboard link: https://syzkaller.appspot.com/bug?extid=a9adaae6a0f1569f2c04
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [linux-...@vger.kernel.org tg...@linutronix.de
net...@vger.kernel.org]

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+a9adaa...@syzkaller.appspotmail.com

sctp: [Deprecated]: syz-executor4 (pid 7944) Use of int in maxseg socket
option.
Use struct sctp_assoc_value instead
BUG: unable to handle kernel paging request at ffffff38858d493f
PGD a51a067 P4D a51a067 PUD 0
Thread overran stack, or stack corrupted
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 16 Comm: ��ف��� Not tainted 4.20.0-rc7+ #358
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__enqueue_entity+0x84/0x1f0 kernel/sched/fair.c:548
Code: 24 48 85 db 74 30 41 80 3f 00 0f 85 ff 00 00 00 48 8d 7b 40 4d 8b 66
58 48 89 f9 48 c1 e9 03 42 80 3c 29 00 0f 85 c4 00 00 00 <4c> 3b 63 40 79
b2 4c 8d 63 10 eb b2 49 8d 5e 18 48 b8 00 00 00 00
RSP: 0018:ffff8881daf073b0 EFLAGS: 00010046
RAX: 1ffffffff0dc2a11 RBX: ffffff38858d48ff RCX: 1fffffe710b1a927
RDX: 0000000000000000 RSI: ffff8881daf2cd70 RDI: ffffff38858d493f
RBP: ffff8881daf073f8 R08: ffff8881d7ab6558 R09: 1ffff1103af56cd5
R10: ffff8881d7ab6688 R11: 1ffff1103b5e0e2c R12: 0000001351e729e1
R13: dffffc0000000000 R14: ffff8881d7ab6500 R15: ffffed103af56cab
FS: 0000000000000000(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffff38858d493f CR3: 000000019ae0f000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
enqueue_entity+0x34b/0x1ff0 kernel/sched/fair.c:3902
enqueue_task_fair+0x24d/0xa50 kernel/sched/fair.c:5106
enqueue_task kernel/sched/core.c:730 [inline]
activate_task+0x136/0x430 kernel/sched/core.c:751
ttwu_activate kernel/sched/core.c:1643 [inline]
ttwu_do_activate+0xd5/0x1f0 kernel/sched/core.c:1702
ttwu_queue kernel/sched/core.c:1847 [inline]
try_to_wake_up+0x9a3/0x1460 kernel/sched/core.c:2057
wake_up_process+0x10/0x20 kernel/sched/core.c:2129
hrtimer_wakeup+0x48/0x60 kernel/time/hrtimer.c:1646
__run_hrtimer kernel/time/hrtimer.c:1398 [inline]
__hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1460
hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline]
smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
</IRQ>
Modules linked in:
CR2: ffffff38858d493f
---[ end trace fba4772489f7c5b5 ]---
RIP: 0010:__enqueue_entity+0x84/0x1f0 kernel/sched/fair.c:548
Code: 24 48 85 db 74 30 41 80 3f 00 0f 85 ff 00 00 00 48 8d 7b 40 4d 8b 66
58 48 89 f9 48 c1 e9 03 42 80 3c 29 00 0f 85 c4 00 00 00 <4c> 3b 63 40 79
b2 4c 8d 63 10 eb b2 49 8d 5e 18 48 b8 00 00 00 00
RSP: 0018:ffff8881daf073b0 EFLAGS: 00010046
RAX: 1ffffffff0dc2a11 RBX: ffffff38858d48ff RCX: 1fffffe710b1a927
RDX: 0000000000000000 RSI: ffff8881daf2cd70 RDI: ffffff38858d493f
RBP: ffff8881daf073f8 R08: ffff8881d7ab6558 R09: 1ffff1103af56cd5
R10: ffff8881d7ab6688 R11: 1ffff1103b5e0e2c R12: 0000001351e729e1
R13: dffffc0000000000 R14: ffff8881d7ab6500 R15: ffffed103af56cab
FS: 0000000000000000(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffff38858d493f CR3: 000000019ae0f000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

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