------------[ cut here ]------------
!valid_signal(sig)
WARNING: kernel/signal.c:2174 at do_notify_parent+0xd18/0xe30 kernel/signal.c:2174, CPU#1: syz.2.171/6372
Modules linked in:
CPU: 1 UID: 0 PID: 6372 Comm: syz.2.171 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:do_notify_parent+0xd18/0xe30 kernel/signal.c:2174
Code: c6 05 a8 99 70 0e 01 48 c7 c7 80 4c cb 8b be a3 08 00 00 48 c7 c2 00 4e cb 8b e8 23 6f 17 00 e9 2e fa ff ff e8 59 35 3b 00 90 <0f> 0b 90 45 31 e4 e9 1c ff ff ff e8 48 35 3b 00 90 0f 0b 90 e9 db
RSP: 0018:ffffc9000653fc40 EFLAGS: 00010093
RAX: ffffffff818b5777 RBX: dffffc0000000000 RCX: ffff888058a21e80
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000000000040
RBP: ffffc9000653fd90 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000ca7fa4 R12: ffff8880292e2450
R13: ffff888058a21e80 R14: 0000000000000080 R15: 1ffff92000ca7f90
FS:  0000000000000000(0000) GS:ffff888125549000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f25c9b456b8 CR3: 000000007c0b8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 exit_notify kernel/exit.c:756 [inline]
 do_exit+0x15b3/0x2490 kernel/exit.c:986
 __do_sys_exit kernel/exit.c:1083 [inline]
 __se_sys_exit kernel/exit.c:1081 [inline]
 __x64_sys_exit+0x40/0x40 kernel/exit.c:1081
 x64_sys_call+0x2231/0x2240 arch/x86/include/generated/asm/syscalls_64.h:61
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c0739c799
Code: Unable to access opcode bytes at 0x7f5c0739c76f.
RSP: 002b:0000200000000018 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007f5c0739c799
RDX: 00007f5c0739c799 RSI: 0000200000000040 RDI: 000000000000000b
RBP: 00007f5c07432bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5c07616038 R14: 00007f5c07615fa0 R15: 00007ffda09867e8
 </TASK>