------------[ cut here ]------------
!valid_signal(sig)
WARNING: kernel/signal.c:2174 at do_notify_parent+0xd18/0xe30 kernel/signal.c:2174, CPU#1: syz.6.573/8545
Modules linked in:
CPU: 1 UID: 0 PID: 8545 Comm: syz.6.573 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:do_notify_parent+0xd18/0xe30 kernel/signal.c:2174
Code: c6 05 c8 ae 8f 0e 01 48 c7 c7 e0 3a cb 8b be a3 08 00 00 48 c7 c2 60 3c cb 8b e8 c3 91 17 00 e9 2e fa ff ff e8 09 5a 3b 00 90 <0f> 0b 90 45 31 e4 e9 1c ff ff ff e8 f8 59 3b 00 90 0f 0b 90 e9 db
RSP: 0018:ffffc900071afc40 EFLAGS: 00010093
RAX: ffffffff818a5dd7 RBX: dffffc0000000000 RCX: ffff8880294abe00
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000000000040
RBP: ffffc900071afd90 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000e35fa4 R12: ffff888032428e90
R13: ffff8880294abe00 R14: 0000000000000080 R15: 1ffff92000e35f90
FS:  0000000000000000(0000) GS:ffff88812539f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000002a2000 CR3: 0000000078428000 CR4: 00000000003526f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 exit_notify kernel/exit.c:758 [inline]
 do_exit+0x13f1/0x22c0 kernel/exit.c:988
 __do_sys_exit kernel/exit.c:1086 [inline]
 __se_sys_exit kernel/exit.c:1084 [inline]
 __x64_sys_exit+0x40/0x40 kernel/exit.c:1084
 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+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f06fdd9ce59
Code: Unable to access opcode bytes at 0x7f06fdd9ce2f.
RSP: 002b:00002000000051d8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007f06fdd9ce59
RDX: 00007f06fdd9ce59 RSI: 0000200000005200 RDI: 000000000000000b
RBP: 00007f06fde32d6f R08: 0000200000005840 R09: 105ff2ed2bdf9f3f
R10: 0000200000005840 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f06fe016128 R14: 00007f06fe016090 R15: 00007ffc8d82ac78
 </TASK>