panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 953 Starting stack trace... panic(ffffffff8333feea) at panic+0x1ba sys/kern/subr_prf.c:229 __assert(ffffffff83379274,ffffffff833d87ec,3b9,ffffffff833b29a3) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff8000ffff2b50,ffffffff833328d1) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:954 pppx_if_destroy(0,ffff8000ffff2b48) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b9a,1,2000,ffff80002a7aba08) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003c963730) at spec_close+0x417 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd807b9a2710,1,fffffd8007bfb3a8,ffff80002a7aba08) at VOP_CLOSE+0x129 sys/kern/vfs_vops.c:156 vn_closefile(fffffd806ba4b780,ffff80002a7aba08) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806ba4b780,ffff80002a7aba08) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615 fdrop(fffffd806ba4b780,ffff80002a7aba08) at fdrop+0x121 sys/kern/kern_descrip.c:1280 closef(fffffd806ba4b780,ffff80002a7aba08) at closef+0x190 sys/kern/kern_descrip.c:1264 syscall(ffff80003c963980) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80003c963980) at syscall+0x962 sys/arch/amd64/amd64/trap.c:746 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x519ff379cc0, count: 245 End of stack trace.