panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 957
Starting stack trace...
panic(ffffffff8344fa23) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff833f9d11,ffffffff833fcfab,3bd,ffffffff833fcff3) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80002a494418,ffffffff83345877) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:958
pppx_if_destroy(285b9a,ffff80002a494410) at pppx_if_destroy+0x3d sys/net/if_pppx.c:806
pppxclose(285b9a,1,2000,ffff8000338a9738) at pppxclose+0xa0 sys/net/if_pppx.c:553
spec_close(ffff80002a4e2b50) at spec_close+0x412 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd8079157610,1,fffffd807f7d3618,ffff8000338a9738) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806be10bf8,ffff8000338a9738) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd806be10bf8,ffff8000338a9738) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd806be10bf8,ffff8000338a9738) at fdrop+0x126 sys/kern/kern_descrip.c:1265
closef(fffffd806be10bf8,ffff8000338a9738) at closef+0x192 sys/kern/kern_descrip.c:1249
fdfree(ffff8000338a9738) at fdfree+0x116 sys/kern/kern_descrip.c:1181
exit1(ffff8000338a9738,0,0,1) at exit1+0x58f sys/kern/kern_exit.c:214
sys_exit(ffff8000338a9738,ffff80002a4e2ec0,ffff80002a4e2e10) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a4e2ec0) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a4e2ec0) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7daa11b44df0, count: 242
End of stack trace.