panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 994
Starting stack trace...
panic(ffffffff8346a1fc) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff8341539a,ffffffff8341d5e8,3e2,ffffffff8341d630) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80002efda928,ffffffff83359224) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:995
pppx_if_destroy(0,ffff80002efda920) at pppx_if_destroy+0x3d sys/net/if_pppx.c:806
pppxclose(205b9a,1,2000,ffff8000ffff07d0) at pppxclose+0xa0 sys/net/if_pppx.c:553
spec_close(ffff80002a3cc730) at spec_close+0x412 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd8066f9c978,1,fffffd80097fb4e0,ffff8000ffff07d0) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806c6b1870,ffff8000ffff07d0) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd806c6b1870,ffff8000ffff07d0) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd806c6b1870,ffff8000ffff07d0) at fdrop+0x126 sys/kern/kern_descrip.c:1267
closef(fffffd806c6b1870,ffff8000ffff07d0) at closef+0x192 sys/kern/kern_descrip.c:1251
fdfree(ffff8000ffff07d0) at fdfree+0x116 sys/kern/kern_descrip.c:1182
exit1(ffff8000ffff07d0,0,0,1) at exit1+0x5a0 sys/kern/kern_exit.c:215
sys_exit(ffff8000ffff07d0,ffff80002a3ccaa0,ffff80002a3cc9f0) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a3ccaa0) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a3ccaa0) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:579
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x744a193f96b0, count: 242
End of stack trace.