------------[ cut here ]------------
!valid_signal(sig)
WARNING: kernel/signal.c:2174 at do_notify_parent+0xd0e/0xe20 kernel/signal.c:2174, CPU#1: syz.2.211/6576
Modules linked in:
CPU: 1 UID: 0 PID: 6576 Comm: syz.2.211 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+0xd0e/0xe20 kernel/signal.c:2174
Code: c6 05 02 4c 8f 0e 01 48 c7 c7 00 3b cb 8b be a3 08 00 00 48 c7 c2 80 3c cb 8b e8 cd 7b 17 00 e9 2d fa ff ff e8 e3 2f 3b 00 90 <0f> 0b 90 45 31 e4 e9 1c ff ff ff e8 d2 2f 3b 00 90 0f 0b 90 e9 e5
RSP: 0018:ffffc9001b42f9c0 EFLAGS: 00010093
RAX: ffffffff818a1fdd RBX: dffffc0000000000 RCX: ffff88801db73e00
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000000000040
RBP: ffffc9001b42fb30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52003685f58 R12: ffff88802fbb1d10
R13: ffff88801db73e00 R14: 0000000000000080 R15: 1ffff92003685f44
FS:  0000000000000000(0000) GS:ffff8881253af000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f54fe9e3ff8 CR3: 00000000332ce000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 exit_notify kernel/exit.c:758 [inline]
 do_exit+0x13f8/0x2360 kernel/exit.c:988
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1119
 get_signal+0x121b/0x12c0 kernel/signal.c:3037
 arch_do_signal_or_restart+0xbb/0x860 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/0x8e0 kernel/entry/common.c:162
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f4bca79ce61
Code: Unable to access opcode bytes at 0x7f4bca79ce37.
RSP: 002b:00000000ffffffb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f4bcaa15fa0 RCX: 00007f4bca79ce59
RDX: 0000000000000000 RSI: 00000000ffffffb0 RDI: 0000000000800480
RBP: 00007f4bca832d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f4bcaa16038 R14: 00007f4bcaa15fa0 R15: 00007fffe0d525f8
 </TASK>