------------[ cut here ]------------
!valid_signal(sig)
WARNING: kernel/signal.c:2174 at do_notify_parent+0xd18/0xe30 kernel/signal.c:2174, CPU#1: syz.0.19/5855
Modules linked in:
CPU: 1 UID: 0 PID: 5855 Comm: syz.0.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:do_notify_parent+0xd18/0xe30 kernel/signal.c:2174
Code: c6 05 20 13 90 0e 01 48 c7 c7 e0 3a cb 8b be a3 08 00 00 48 c7 c2 60 3c cb 8b e8 93 8c 17 00 e9 2e fa ff ff e8 79 50 3b 00 90 <0f> 0b 90 45 31 e4 e9 1c ff ff ff e8 68 50 3b 00 90 0f 0b 90 e9 db
RSP: 0018:ffffc900036e79e0 EFLAGS: 00010093
RAX: ffffffff818a6bc7 RBX: dffffc0000000000 RCX: ffff88802f338000
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000000000040
RBP: ffffc900036e7b30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520006dcf58 R12: ffff8880268c6cd0
R13: ffff88802f338000 R14: 0000000000000080 R15: 1ffff920006dcf44
FS:  0000000000000000(0000) GS:ffff888125390000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555e21b4e8 CR3: 000000000e74a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 exit_notify kernel/exit.c:757 [inline]
 do_exit+0x13f1/0x22c0 kernel/exit.c:987
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117
 get_signal+0x1284/0x1330 kernel/signal.c:3037
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:252 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:323 [inline]
 irqentry_exit+0x284/0x730 kernel/entry/common.c:162
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7ff1abd9cde1
Code: Unable to access opcode bytes at 0x7ff1abd9cdb7.
RSP: 002b:0000000000000020 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007ff1ac015fa0 RCX: 00007ff1abd9cdd9
RDX: 0000000000000000 RSI: 0000000000000020 RDI: 0000000080004080
RBP: 00007ff1abe32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ff1ac015fac R14: 00007ff1ac015fa0 R15: 00007ff1ac015fa0
 </TASK>