panic: Data modified on freelist: word 6 of object 0xffff80000131b000 size 0x1800 previous type proc (0xdeaf4153 != 0xdeaf4152)

Starting stack trace...
panic(ffffffff830133e2) at panic+0x1ba sys/kern/subr_prf.c:229
malloc(1800,29,9) at malloc+0xd7c sys/kern/kern_malloc.c:349
unveil_add(ffff80002a4d0020,ffff80002a53d858,ffff80002a53d913) at unveil_add+0x1dd sys/kern/kern_unveil.c:423
sys_unveil(ffff80002a4d0020,ffff80002a53da40,ffff80002a53d990) at sys_unveil+0x60c sys/kern/vfs_syscalls.c:1020
syscall(ffff80002a53da40) at syscall+0x97e sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7eecbff73d70, count: 251
End of stack trace.