panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 955
Starting stack trace...
panic(ffffffff83412687) at panic+0x1ba sys/kern/subr_prf.c:229
__assert(ffffffff83453dd9,ffffffff834aded3,3bb,ffffffff83486f8b) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80003c92b0b0,ffffffff8340e16b) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:956
pppx_if_destroy(205b9c,ffff80003c92b0a8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794
pppxclose(205b9c,81,2000,ffff80003b0e8a98) at pppxclose+0xa0 sys/net/if_pppx.c:541
spec_close(ffff80003acf7280) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd805b9cc530,81,fffffd8007ffd270,ffff80003b0e8a98) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156
vn_closefile(fffffd8060d914c8,ffff80003b0e8a98) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd8060d914c8,ffff80003b0e8a98) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615
fdrop(fffffd8060d914c8,ffff80003b0e8a98) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffffd8060d914c8,ffff80003b0e8a98) at closef+0x190 sys/kern/kern_descrip.c:1265
fdfree(ffff80003b0e8a98) at fdfree+0x115 sys/kern/kern_descrip.c:1196
exit1(ffff80003b0e8a98,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff80003b0e8a98,ffff80003acf75e0,ffff80003acf7530) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80003acf75e0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003acf75e0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x780a83fe2850, count: 242
End of stack trace.