syzbot

panic: trap type 4, code=0, pc=ffffffff827d53b7
Starting stack trace...
panic(ffffffff833332c9) at panic+0x1d0 sys/kern/subr_prf.c:229
kerntrap(ffff80003c4e4010) at kerntrap+0x29b sys/arch/amd64/amd64/trap.c:327
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
lf_advlock(ffff8000014580a0,0,fffffd806c549a28,2,ffff80003c4e4200,20) at lf_advlock+0x2f7 ls_ref sys/kern/vfs_lockf.c:138 [inline]
lf_advlock(ffff8000014580a0,0,fffffd806c549a28,2,ffff80003c4e4200,20) at lf_advlock+0x2f7 sys/kern/vfs_lockf.c:278
VOP_ADVLOCK(fffffd806c237638,fffffd806c549a28,2,ffff80003c4e4200,20) at VOP_ADVLOCK+0x87 sys/kern/vfs_vops.c:620
vn_closefile(fffffd806c549a28,ffff8000393faa68) at vn_closefile+0xba sys/kern/vfs_vnops.c:615
fdrop(fffffd806c549a28,ffff8000393faa68) at fdrop+0x126 sys/kern/kern_descrip.c:1265
closef(fffffd806c549a28,ffff8000393faa68) at closef+0x192 sys/kern/kern_descrip.c:1249
finishdup(ffff8000393faa68,fffffd806be74218,5,4,ffff80003c4e43f0,2) at finishdup+0x444 sys/kern/kern_descrip.c:677
syscall(ffff80003c4e44a0) at syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4e44a0) at syscall+0xbc6 sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x6aae49cd9f0, count: 246
End of stack trace.