panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 953
Starting stack trace...
panic(ffffffff83394ffb) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff833d3acc,ffffffff833de77f,3b9,ffffffff83408422) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80003bc0e348,ffffffff8338daa7) at refcnt_finalize+0x1db sys/kern/kern_synch.c:954
pppx_if_destroy(205b9a,ffff80003bc0e340) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794
pppxclose(205b9a,1,2000,ffff8000fffe14f0) at pppxclose+0xa0 sys/net/if_pppx.c:541
spec_close(ffff80003bc049a0) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd8060209cc0,1,fffffd80097fb0d0,ffff8000fffe14f0) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd8061260b90,ffff8000fffe14f0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd8061260b90,ffff8000fffe14f0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd8061260b90,ffff8000fffe14f0) at fdrop+0x121 sys/kern/kern_descrip.c:1280
closef(fffffd8061260b90,ffff8000fffe14f0) at closef+0x192 sys/kern/kern_descrip.c:1264
fdfree(ffff8000fffe14f0) at fdfree+0x116 sys/kern/kern_descrip.c:1195
exit1(ffff8000fffe14f0,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff8000fffe14f0,ffff80003bc04d10,ffff80003bc04c60) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003bc04d10) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003bc04d10) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:765
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7e561fcfa210, count: 242
End of stack trace.