------------[ cut here ]------------
WARNING: [!valid_signal(sig)] kernel/signal.c:2174 at do_notify_parent+0xe1c/0xfc0 kernel/signal.c:2174, CPU#0: syz.1.316/4643
Modules linked in:
CPU: 0 UID: 0 PID: 4643 Comm: syz.1.316 Tainted: G        W           syzkaller #0 PREEMPT 
Tainted: [W]=WARN
Hardware name: riscv-virtio,qemu (DT)
epc : do_notify_parent+0xe1c/0xfc0 kernel/signal.c:2174
 ra : do_notify_parent+0xe1c/0xfc0 kernel/signal.c:2174
epc : ffffffff80196b64 ra : ffffffff80196b64 sp : ffff8f800a077790
 gp : ffffffff8a2739a0 tp : ffffaf801adeb500 t0 : ffff8f800a0776e0
 t1 : 0000000041b58ab3 t2 : ffffffff9164ab80 s0 : ffff8f800a077920
 s1 : ffffaf801adeb500 a0 : 0000000000000007 a1 : 0000000000000040
 a2 : 0000000000000002 a3 : ffffffff80196b64 a4 : 0000000000000000
 a5 : ffffaf801adec500 a6 : 0000000000000003 a7 : fffffffff1f1f1f1
 s2 : ffff8f800a0778a0 s3 : 0000000000000080 s4 : ffff8f800a077830
 s5 : dfffffff00000000 s6 : 0000000000000001 s7 : ffffaf8016a70000
 s8 : 1ffff1f00140eef8 s9 : ffff8f800a0779a0 s10: 0000000000000001
 s11: ffff8f800a077ba0 t3 : ffffffff80195d48 t4 : ffffffff88075c30
 t5 : fffff1ef0140ef0d t6 : 0000000000000002 ssp : 0000000000000000
status: 0000000200000100 badaddr: ffffffff80196b64 cause: 0000000000000003
[<ffffffff80196b64>] do_notify_parent+0xe1c/0xfc0 kernel/signal.c:2174
[<ffffffff80164778>] exit_notify kernel/exit.c:758 [inline]
[<ffffffff80164778>] do_exit+0x1810/0x2a18 kernel/exit.c:988
[<ffffffff80165eae>] do_group_exit+0xca/0x258 kernel/exit.c:1119
[<ffffffff8019fb66>] get_signal+0x1f56/0x2224 kernel/signal.c:3037
[<ffffffff80072924>] arch_do_signal_or_restart+0xf4/0x1e08 arch/riscv/kernel/signal.c:534
[<ffffffff8646b1b4>] __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
[<ffffffff8646b1b4>] exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
[<ffffffff8646b1b4>] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
[<ffffffff8646b1b4>] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
[<ffffffff8646b1b4>] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
[<ffffffff8646b1b4>] irqentry_exit+0x540/0x11ac kernel/entry/common.c:162
[<ffffffff86469e12>] do_page_fault+0x3e/0x58 arch/riscv/kernel/traps.c:420
[<ffffffff86494da4>] handle_exception+0x168/0x174 arch/riscv/kernel/entry.S:237