KASAN: stack-out-of-bounds Read in update_min_vruntime

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 6fcf9b1d4d6c r8169: fix runtime suspend
git tree: bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13fa3968400000
kernel config: https://syzkaller.appspot.com/x/.config?x=d264f2b04177ca7c
dashboard link: https://syzkaller.appspot.com/bug?extid=1f4d2dc3069001a7c288
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [linux-...@vger.kernel.org tg...@linutronix.de]

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+1f4d2d...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: stack-out-of-bounds in update_min_vruntime+0x182/0x1a0
kernel/sched/fair.c:521
Read of size 8 at addr ffff88019fa386d8 by task syz-executor2/4449

CPU: 0 PID: 4449 Comm: syz-executor2 Not tainted 4.18.0-rc3+ #47
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
PANIC: double fault, error_code: 0x0
update_min_vruntime+0x182/0x1a0 kernel/sched/fair.c:521
CPU: 1 PID: 10520 Comm: syz-executor3 Not tainted 4.18.0-rc3+ #47
update_curr+0x200/0xc00 kernel/sched/fair.c:826
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__lock_acquire+0x2e/0x5020 kernel/locking/lockdep.c:3294
Code:
41
57
41
89
enqueue_entity+0x40d/0x2130 kernel/sched/fair.c:4195
cf
41
56
41
55
49
89
fd 41
54 45
89
cc
53
65
enqueue_task_fair+0x22d/0x910 kernel/sched/fair.c:5408
4c 8b
34 25
40
ee 01
00 48
enqueue_task kernel/sched/core.c:751 [inline]
activate_task+0x123/0x2e0 kernel/sched/core.c:770
83 e4
ttwu_activate kernel/sched/core.c:1659 [inline]
ttwu_do_activate+0xd5/0x1f0 kernel/sched/core.c:1718
f0
ttwu_queue kernel/sched/core.c:1863 [inline]
try_to_wake_up+0x948/0x12b0 kernel/sched/core.c:2076
48 81
ec
60 03
00
00
48 8b
45
10 <89>
94
24
80
00 00
00
wake_up_process+0x10/0x20 kernel/sched/core.c:2149
48
hrtimer_wakeup+0x48/0x60 kernel/time/hrtimer.c:1647
ba
__run_hrtimer kernel/time/hrtimer.c:1398 [inline]
__hrtimer_run_queues+0x3eb/0x10c0 kernel/time/hrtimer.c:1460
00
00
00
00
00
fc
ff
df
48 89 84 24
98
hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
RSP: 0018:ffff8801987ffda0 EFLAGS: 00010086
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
smp_apic_timer_interrupt+0x165/0x730 arch/x86/kernel/apic/apic.c:1050
RAX: 0000000000000000 RBX: 1ffff10033100030 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff88f92620
RBP: ffff880198800128 R08: 0000000000000000 R09: 0000000000000000
R10: ffff88019fdc71b8 R11: ffff8801daf236b3 R12: 0000000000000000
R13: ffffffff88f92620 R14: ffff8801bd6662c0 R15: 0000000000000002
FS: 00007fd5108e0700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
CR2: ffff8801987ffd98 CR3: 00000001a2982000 CR4: 00000000001406e0
</IRQ>
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
RIP: 0010:arch_atomic_inc arch/x86/include/asm/atomic.h:96 [inline]
RIP: 0010:atomic_inc include/asm-generic/atomic-instrumented.h:103 [inline]
RIP: 0010:get_bh include/linux/buffer_head.h:283 [inline]
RIP: 0010:ext4_mark_iloc_dirty+0x1f5/0x30b0 fs/ext4/inode.c:5769
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Code:
Call Trace:
c1


---
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[Dmitry Vyukov]

the bpf socket map bug

#syz invalid

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