syzbot

panic: trap type 4, code=0, pc=ffffffff82564739
Starting stack trace...
panic(ffffffff830555a5) at panic+0x1d0 sys/kern/subr_prf.c:229
kerntrap(ffff80003c61a5a0) at kerntrap+0x29b sys/arch/amd64/amd64/trap.c:327
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
sys_semop(ffff8000ffffdbe0,ffff80003c61a850,ffff80003c61a7a0) at sys_semop+0x3f9 sys/kern/sysv_sem.c:602
syscall(ffff80003c61a850) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c61a850) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xe03908caeb0, count: 251
End of stack trace.