[syzbot] [kernel?] WARNING in posixtimer_send_sigqueue (2)

syzbot
2024-12-17T17:14:23Z

Hello,

syzbot found the following issue on:

HEAD commit: 78d4f34e2115 Linux 6.13-rc3
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10010b44580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b86955f5c0c7be27
dashboard link: https://syzkaller.appspot.com/bug?extid=3c2e3cc60665d71de2f7
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10d4b4f8580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132b9730580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-78d4f34e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e3d545fe5a74/vmlinux-78d4f34e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3c244cffe535/bzImage-78d4f34e.xz

The issue was bisected to:

commit df7a996b4dab03c889fa86d849447b716f07b069
Author: Thomas Gleixner <tglx@linutronix.de>
Date: Tue Nov 5 08:14:54 2024 +0000

signal: Queue ignored posixtimers on ignore list

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=110727e8580000
final oops: https://syzkaller.appspot.com/x/report.txt?x=130727e8580000
console output: https://syzkaller.appspot.com/x/log.txt?x=150727e8580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3c2e3cc60665d71de2f7@syzkaller.appspotmail.com
Fixes: df7a996b4dab ("signal: Queue ignored posixtimers on ignore list")

------------[ cut here ]------------
WARNING: CPU: 1 PID: 5933 at kernel/signal.c:2050 posixtimer_send_sigqueue+0xba8/0x1020 kernel/signal.c:2050
Modules linked in:
CPU: 1 UID: 0 PID: 5933 Comm: syz-executor261 Not tainted 6.13.0-rc3-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:posixtimer_send_sigqueue+0xba8/0x1020 kernel/signal.c:2050
Code: ff ff 4c 89 e7 e8 98 ff 9d 00 e9 7e f8 ff ff 41 bf 02 00 00 00 e9 87 f8 ff ff 48 89 54 24 10 48 89 44 24 08 e8 59 51 3b 00 90 <0f> 0b 90 48 8d 7b 10 48 8b 44 24 08 48 b9 00 00 00 00 00 fc ff df
RSP: 0018:ffffc900006b0d50 EFLAGS: 00010046
RAX: 0000000080010003 RBX: ffff888031d62000 RCX: 1ffff110063ac403
RDX: ffff888022920000 RSI: ffffffff815ec2e7 RDI: 0000000000000001
RBP: ffff888029fb2440 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000003 R12: ffff888031d620a4
R13: 1ffff920000d61af R14: ffff888031d620d8 R15: ffff888031d620c0
FS: 00007fb777ee36c0(0000) GS:ffff88806a700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020040fe0 CR3: 0000000023c34000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
posix_timer_fn+0x31/0x60 kernel/time/posix-timers.c:323
__run_hrtimer kernel/time/hrtimer.c:1739 [inline]
__hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1803
hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1865
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 86 04 4b f6 48 89 df e8 ce 83 4b f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 c5 68 3c f6 65 8b 05 96 23 d8 74 85 c0 74 16 5b
RSP: 0018:ffffc900028f7d58 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff888031d62030 RCX: 1ffffffff20bdd41
RDX: 0000000000000000 RSI: ffffffff8b6cd840 RDI: ffffffff8bd1e7e0
RBP: 0000000000000293 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff905f2c57 R11: 0000000000000002 R12: ffffc900028f7e50
R13: 0000000000000000 R14: 1ffff9200051efb1 R15: dffffc0000000000
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
unlock_timer kernel/time/posix-timers.c:128 [inline]
do_timer_settime+0x315/0x400 kernel/time/posix-timers.c:908
__do_sys_timer_settime kernel/time/posix-timers.c:928 [inline]
__se_sys_timer_settime kernel/time/posix-timers.c:914 [inline]
__x64_sys_timer_settime+0x26a/0x2c0 kernel/time/posix-timers.c:914
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb777f283a9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 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 01 48
RSP: 002b:00007fb777ee3228 EFLAGS: 00000246 ORIG_RAX: 00000000000000df
RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007fb777f283a9
RDX: 0000000020040fe0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb777fb2308 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb777fb2300
R13: 00007fb777fb230c R14: 00007fffae0f2ba0 R15: 00007fffae0f2c88
</TASK>
----------------
Code disassembly (best guess):
0: f5 cmc
1: 53 push %rbx
2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi
7: 48 89 fb mov %rdi,%rbx
a: 48 83 c7 18 add $0x18,%rdi
e: e8 86 04 4b f6 call 0xf64b0499
13: 48 89 df mov %rbx,%rdi
16: e8 ce 83 4b f6 call 0xf64b83e9
1b: f7 c5 00 02 00 00 test $0x200,%ebp
21: 75 23 jne 0x46
23: 9c pushf
24: 58 pop %rax
25: f6 c4 02 test $0x2,%ah
28: 75 37 jne 0x61
* 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction
2f: e8 c5 68 3c f6 call 0xf63c68f9
34: 65 8b 05 96 23 d8 74 mov %gs:0x74d82396(%rip),%eax # 0x74d823d1
3b: 85 c0 test %eax,%eax
3d: 74 16 je 0x55
3f: 5b pop %rbx

---
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