------------[ cut here ]------------
!valid_signal(sig)
WARNING: kernel/signal.c:2174 at do_notify_parent+0xd18/0xe30 kernel/signal.c:2174, CPU#1: syz.8.2086/15402
Modules linked in:
CPU: 1 UID: 0 PID: 15402 Comm: syz.8.2086 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:ffffc9000584f9e0 EFLAGS: 00010093
RAX: ffffffff818a5dd7 RBX: dffffc0000000000 RCX: ffff88807aad3e00
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000000000040
RBP: ffffc9000584fb30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000b09f58 R12: ffff88801cf432d0
R13: ffff88807aad3e00 R14: 0000000000000080 R15: 1ffff92000b09f44
FS:  0000000000000000(0000) GS:ffff88812539f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561a23df1003 CR3: 000000007f4a6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000200000000300 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_group_exit+0x21b/0x2d0 kernel/exit.c:1119
 get_signal+0x1284/0x1330 kernel/signal.c:3037
 arch_do_signal_or_restart+0xbc/0x840 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:244 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
 irqentry_exit+0x2aa/0x8b0 kernel/entry/common.c:162
 asm_exc_stack_segment+0x26/0x30 arch/x86/include/asm/idtentry.h:611
RIP: 0033:0x7f8b4619ce61
Code: Unable to access opcode bytes at 0x7f8b4619ce37.
RSP: 002b:c8b1ec5e9918acf0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f8b46415fa0 RCX: 00007f8b4619ce59
RDX: 0000000000000000 RSI: c8b1ec5e9918acf0 RDI: 0000000000042280
RBP: 00007f8b46232d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f8b46416038 R14: 00007f8b46415fa0 R15: 00007ffe9c121f78
 </TASK>