------------[ cut here ]------------
!valid_signal(sig)
WARNING: kernel/signal.c:2174 at do_notify_parent+0xea8/0x10b0 kernel/signal.c:2174, CPU#0: syz.4.848/8312
Modules linked in:
CPU: 0 UID: 0 PID: 8312 Comm: syz.4.848 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:do_notify_parent+0xea8/0x10b0 kernel/signal.c:2174
Code: f4 ff ff e8 8a f4 3d 00 41 c1 ff 08 c7 84 24 90 00 00 00 01 00 00 00 44 89 bc 24 a0 00 00 00 e9 92 f8 ff ff e8 69 f4 3d 00 90 <0f> 0b 90 45 31 f6 e9 f5 f9 ff ff e8 58 f4 3d 00 90 0f 0b 90 e9 43
RSP: 0018:ffffc9000eaefa98 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffff88804ba00000 RCX: ffffffff81caaf8b
RDX: ffff88804ba00000 RSI: ffffffff81cabd77 RDI: ffff88804ba00000
RBP: 0000000000000080 R08: 0000000000000007 R09: 0000000000000040
R10: 0000000000000080 R11: 0000000000000000 R12: 1ffff92001d5df56
R13: dffffc0000000000 R14: 0000000000000080 R15: ffff88807de7a500
FS:  0000000000000000(0000) GS:ffff88812436a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f89129456b8 CR3: 00000000442ea000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 exit_notify kernel/exit.c:758 [inline]
 do_exit+0x1b84/0x2af0 kernel/exit.c:988
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1119
 get_signal+0x20ff/0x2210 kernel/signal.c:3037
 arch_do_signal_or_restart+0x91/0x7e0 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+0x410/0x7e0 kernel/entry/common.c:162
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x4dddfe
Code: Unable to access opcode bytes at 0x4dddd4.
RSP: 002b:0000200000000478 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fe568c15fa0 RCX: 00007fe56899ce59
RDX: 0000200000000040 RSI: 0000200000000470 RDI: 0000000002000080
RBP: 00007fe568a32d6f R08: 0000200000000300 R09: 0000200000000300
R10: 0000200000000280 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fe568c16038 R14: 00007fe568c15fa0 R15: 00007ffc4ca0bc28
 </TASK>