panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 955
Starting stack trace...
panic(ffffffff8340c772) at panic+0x1ba sys/kern/subr_prf.c:229
__assert(ffffffff8344cdf7,ffffffff834a77aa,3bb,ffffffff83480b9c) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80003c9d2b58,ffffffff83402e77) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:956
pppx_if_destroy(0,ffff80003c9d2b50) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794
pppxclose(285b9a,41,2000,ffff80003c970a88) at pppxclose+0xa0 sys/net/if_pppx.c:541
spec_close(ffff800039d0d360) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd806ec24528,41,fffffd8007ffd680,ffff80003c970a88) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806ad48178,ffff80003c970a88) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd806ad48178,ffff80003c970a88) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615
fdrop(fffffd806ad48178,ffff80003c970a88) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffffd806ad48178,ffff80003c970a88) at closef+0x190 sys/kern/kern_descrip.c:1265
fdfree(ffff80003c970a88) at fdfree+0x115 sys/kern/kern_descrip.c:1196
exit1(ffff80003c970a88,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff80003c970a88,ffff800039d0d6c0,ffff800039d0d610) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff800039d0d6c0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff800039d0d6c0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x70631df286c0, count: 242
End of stack trace.