[moderation] [kernel?] general protection fault in try_to_wake_up (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 57b8e2d666a3 Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17e9d2ce580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f2e8ebfec4636d32
dashboard link: https://syzkaller.appspot.com/bug?extid=0fc99cd77bfc4f645f30
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
CC: [linux-...@vger.kernel.org pet...@infradead.org tg...@kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c5dd3f1c8b2c/disk-57b8e2d6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/848543e0035b/vmlinux-57b8e2d6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0705a91c069e/bzImage-57b8e2d6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0fc99c...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc000000015e: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000af0-0x0000000000000af7]
CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 79 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 c3 cc cc cc cc cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc90000a3f8e8 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: ffffffff8b1f8bb0 RCX: 0000000080000003
RDX: 0000000000000000 RSI: ffffffff8b1f8bb0 RDI: 000000000000015e
RBP: ffffffff81943d56 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f11a5f R12: 0000000000000000
R13: 0000000000000af0 R14: 0000000000000af0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812627c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f13c2420000 CR3: 0000000041f5e000 CR4: 00000000003526f0
Call Trace:
<TASK>
__kasan_check_byte+0x12/0x40 mm/kasan/common.c:573
kasan_check_byte include/linux/kasan.h:402 [inline]
lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5842
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:571 [inline]
try_to_wake_up+0x66/0x1380 kernel/sched/core.c:4190
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x6a3/0x9f0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1151
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 79 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 c3 cc cc cc cc cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc90000a3f8e8 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: ffffffff8b1f8bb0 RCX: 0000000080000003
RDX: 0000000000000000 RSI: ffffffff8b1f8bb0 RDI: 000000000000015e
RBP: ffffffff81943d56 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f11a5f R12: 0000000000000000
R13: 0000000000000af0 R14: 0000000000000af0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812627c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f13c2420000 CR3: 0000000041f5e000 CR4: 00000000003526f0
----------------
Code disassembly (best guess), 4 bytes skipped:
0: 0f 1f 40 00 nopl 0x0(%rax)
4: 90 nop
5: 90 nop
6: 90 nop
7: 90 nop
8: 90 nop
9: 90 nop
a: 90 nop
b: 90 nop
c: 90 nop
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 0f 1f 40 d6 nopl -0x2a(%rax)
18: 48 c1 ef 03 shr $0x3,%rdi
1c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
23: fc ff df
* 26: 0f b6 04 07 movzbl (%rdi,%rax,1),%eax <-- trapping instruction
2a: 3c 08 cmp $0x8,%al
2c: 0f 92 c0 setb %al
2f: c3 ret
30: cc int3
31: cc int3
32: cc int3
33: cc int3
34: cc int3
35: 66 data16
36: 66 data16
37: 66 data16
38: 66 data16
39: 66 data16
3a: 66 data16
3b: 2e cs


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