panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 951 Starting stack trace... panic(ffffffff8342ec89) at panic+0x1ba sys/kern/subr_prf.c:229 __assert(ffffffff833dff0c,ffffffff83329072,3b7,ffffffff833e2453) at __assert+0x29 sys/kern/subr_prf.c:-1 refcnt_finalize(ffff800035d0eb50,ffffffff8332e44e) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:952 pppx_if_destroy(205b92,ffff800035d0eb48) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794 pppxclose(205b92,41,2000,ffff80003a5362b0 ) at pppxclose+0xa0 sys/net/if_pppx.c:541 spec_close(ffff80003a5336f0) at spec_close+0x412 sys/kern/spec_vnops.c:-1 VOP_CLOSE(fffffd8068d472a0,41,fffffd8007bfb4e0,ffff80003a5362b0) at VOP_CLOSE+0x12a sys/kern/vfs_vops.c:156 vn_closefile(fffffd806aedb268,ffff80003a5362b0) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline] vn_closefile(fffffd806aedb268,ffff80003a5362b0) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615 fdrop(fffffd806aedb268,ffff80003a5362b0) at fdrop+0x126 sys/kern/kern_descrip.c:1267 closef(fffffd806aedb268,ffff80003a5362b0) at closef+0x18d sys/kern/kern_descrip.c:1251 syscall(ffff80003a533950) at syscall+0x97e mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80003a533950) at syscall+0x97e sys/arch/amd64/amd64/trap.c:742 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x9c5e196c930, count: 245 End of stack trace. syncing disks...set $lines = 0 set $maxwidth = 0 show panic trace show registers show proc ps show all locks show malloc show all pools machine ddbcpu 0 trace machine ddbcpu 1 trace