[v5.15] WARNING in rcu_check_gp_start_stall

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8a1d809b0545 Linux 5.15.142
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=143d7974e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=ee92f7141049e8f2
dashboard link: https://syzkaller.appspot.com/bug?extid=acdbafbd3e2c31ed774e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8965895d90e2/disk-8a1d809b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f8d2c2cd9799/vmlinux-8a1d809b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4fa328be23e7/bzImage-8a1d809b.xz

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

------------[ cut here ]------------
WARNING: CPU: 0 PID: 29406 at kernel/rcu/tree_stall.h:937 rcu_check_gp_start_stall+0x2c8/0x450 kernel/rcu/tree_stall.h:922
Modules linked in:
CPU: 0 PID: 29406 Comm: syz-executor.3 Not tainted 5.15.142-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
RIP: 0010:rcu_check_gp_start_stall+0x2c8/0x450 kernel/rcu/tree_stall.h:937
Code: c7 c7 60 bc 40 91 be 04 00 00 00 e8 02 73 5e 00 b8 01 00 00 00 87 05 f7 4d d5 0f 85 c0 0f 85 1c ff ff ff 48 c7 c0 80 30 92 8c <0f> 0b 49 39 c7 74 47 48 c7 c0 44 ca e3 8d 48 c1 e8 03 42 0f b6 04
RSP: 0018:ffffc90000007bd8 EFLAGS: 00010046
RAX: ffffffff8c923080 RBX: 000000010002c7e0 RCX: ffffffff816b6e5e
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9140bc60
RBP: ffffc90000007e10 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8c923080
FS: 00007fc6e1e1e6c0(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002006b000 CR3: 0000000032c67000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
rcu_core+0x657/0x1650 kernel/rcu/tree.c:2758
__do_softirq+0x3b3/0x93a kernel/softirq.c:558
invoke_softirq kernel/softirq.c:432 [inline]
__irq_exit_rcu+0x155/0x240 kernel/softirq.c:637
irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1096
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 81 7e f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 9e 3b 3d f7 48 89 df e8 76 8f 3e f7 e8 81 3f 61 f7 fb bf 01 00 00 00 <e8> d6 cb 31 f7 65 8b 05 77 06 dd 75 85 c0 74 02 5b c3 e8 04 1e db
RSP: 0018:ffffc90003827bc0 EFLAGS: 00000282
RAX: cea947cc7bf91c00 RBX: ffff8880199e2e40 RCX: ffffffff913c6f03
RDX: dffffc0000000000 RSI: ffffffff8a8b0d60 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff8186a8f0 R09: ffffed100333c5c9
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000021
R13: dffffc0000000000 R14: ffff8880199e32d8 R15: ffff8880199e2e40
spin_unlock_irq include/linux/spinlock.h:413 [inline]
get_signal+0x13ee/0x14e0 kernel/signal.c:2892
arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301
do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fc6e389cba7
Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89
RSP: 002b:00007fc6e1e1e0c8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fc6e39bbf80 RCX: 00007fc6e389cba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fc6e38e847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fc6e39bbf80 R15: 00007ffd99d37348
</TASK>
----------------
Code disassembly (best guess):
0: 81 7e f6 ff 90 53 48 cmpl $0x485390ff,-0xa(%rsi)
7: 89 fb mov %edi,%ebx
9: 48 83 c7 18 add $0x18,%rdi
d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi
12: e8 9e 3b 3d f7 call 0xf73d3bb5
17: 48 89 df mov %rbx,%rdi
1a: e8 76 8f 3e f7 call 0xf73e8f95
1f: e8 81 3f 61 f7 call 0xf7613fa5
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 d6 cb 31 f7 call 0xf731cc05 <-- trapping instruction
2f: 65 8b 05 77 06 dd 75 mov %gs:0x75dd0677(%rip),%eax # 0x75dd06ad
36: 85 c0 test %eax,%eax
38: 74 02 je 0x3c
3a: 5b pop %rbx
3b: c3 ret
3c: e8 .byte 0xe8
3d: 04 1e add $0x1e,%al
3f: db .byte 0xdb


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[syzbot]

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