panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 959
Starting stack trace...
panic(ffffffff83487227) at panic+0x1ba sys/kern/subr_prf.c:229
__assert(ffffffff834c2827,ffffffff83520e4d,3bf,ffffffff834fa372) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80002a7d7758,ffffffff8347bd6f) at refcnt_finalize+0x1e7 sys/kern/kern_synch.c:960
pppx_if_destroy(0,ffff80002a7d7750) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794
pppxclose(285b9a,1,2000,ffff8000314b34e0) at pppxclose+0xa0 sys/net/if_pppx.c:541
spec_close(ffff80003c994d30) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffa806d2d5a38,1,fffffa8007ffd958,ffff8000314b34e0) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156
vn_closefile(fffffa806d198d98,ffff8000314b34e0) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(fffffa806d198d98,ffff8000314b34e0) at vn_closefile+0x11d sys/kern/vfs_vnops.c:621
fdrop(fffffa806d198d98,ffff8000314b34e0) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffffa806d198d98,ffff8000314b34e0) at closef+0x190 sys/kern/kern_descrip.c:1265
fdfree(ffff8000314b34e0) at fdfree+0x115 sys/kern/kern_descrip.c:1196
exit1(ffff8000314b34e0,0,0,1) at exit1+0x595 sys/kern/kern_exit.c:215
sys_exit(ffff8000314b34e0,ffff80003c995090,ffff80003c994fe0) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003c995090) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c995090) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x743e1fda8e50, count: 242
End of stack trace.