panic: Data modified on freelist: word 4 of object 0xffff800000d40c00 size 0x194 previous type free (0x6563 != 0xdeadbeef)

Starting stack trace...
panic(ffffffff8276d11b) at panic+0x159 sys/kern/subr_prf.c:229
malloc(194,7f,1) at malloc+0xa85 sys/kern/kern_malloc.c:362
vndioctl(2902,20006473,ffff80002e80eb40,1,ffff8000fffe8038) at vndioctl+0x452 sys/dev/vnd.c:610
VOP_IOCTL(fffffd80702c6eb8,20006473,ffff80002e80eb40,1,fffffd807f7d7680,ffff8000fffe8038) at VOP_IOCTL+0x91 sys/kern/vfs_vops.c:264
vn_ioctl(fffffd80683df2e8,20006473,ffff80002e80eb40,ffff8000fffe8038) at vn_ioctl+0xbb sys/kern/vfs_vnops.c:525
sys_ioctl(ffff8000fffe8038,ffff80002e80ec50,ffff80002e80eca0) at sys_ioctl+0x49e
syscall(ffff80002e80ed20) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xa54a09d3f60, count: 249
End of stack trace.