panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 951
Starting stack trace...
panic(ffffffff83339b80) at panic+0x1ba sys/kern/subr_prf.c:229
__assert(ffffffff833764fe,ffffffff833d60ca,3b7,ffffffff833afe55) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80003a55a5e0,ffffffff83331f4d) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:952
pppx_if_destroy(205b9a,ffff80003a55a5d8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794
pppxclose(205b9a,1,2000,ffff80002a900800) at pppxclose+0xa0 sys/net/if_pppx.c:541
spec_close(ffff80002a8095a0) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd806bfe8008,1,fffffd8007bfb478,ffff80002a900800) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156
vn_closefile(fffffd8070740008,ffff80002a900800) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd8070740008,ffff80002a900800) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615
fdrop(fffffd8070740008,ffff80002a900800) at fdrop+0x121 sys/kern/kern_descrip.c:1267
closef(fffffd8070740008,ffff80002a900800) at closef+0x190 sys/kern/kern_descrip.c:1251
fdfree(ffff80002a900800) at fdfree+0x115 sys/kern/kern_descrip.c:1182
exit1(ffff80002a900800,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff80002a900800,ffff80002a809900,ffff80002a809850) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a809900) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a809900) at syscall+0x962 sys/arch/amd64/amd64/trap.c:748
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x72b15dd64a30, count: 242
End of stack trace.