panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 995
Starting stack trace...
panic(ffffffff8347586b) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff8341f0b2,ffffffff8342073f,3e3,ffffffff83420787) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80003c412f10,ffffffff833676ad) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:996
pppx_if_destroy(0,ffff80003c412f08) at pppx_if_destroy+0x3d sys/net/if_pppx.c:806
pppxclose(205b9a,1,2000,ffff8000ffff2010) at pppxclose+0xa0 sys/net/if_pppx.c:553
spec_close(ffff8000333e4480) at spec_close+0x412 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd8078b49b20,1,fffffd80097fb208,ffff8000ffff2010) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806c09cc18,ffff8000ffff2010) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd806c09cc18,ffff8000ffff2010) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd806c09cc18,ffff8000ffff2010) at fdrop+0x126 sys/kern/kern_descrip.c:1267
closef(fffffd806c09cc18,ffff8000ffff2010) at closef+0x192 sys/kern/kern_descrip.c:1251
fdfree(ffff8000ffff2010) at fdfree+0x116 sys/kern/kern_descrip.c:1182
exit1(ffff8000ffff2010,0,0,1) at exit1+0x5a0 sys/kern/kern_exit.c:215
sys_exit(ffff8000ffff2010,ffff8000333e47f0,ffff8000333e4740) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff8000333e47f0) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff8000333e47f0) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:579
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x78ea516b5eb0, count: 242
End of stack trace.