panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/main/kernel/sys/kern/kern_synch.c", line 951
Starting stack trace...
panic(ffffffff8343109f) at panic+0x1ba sys/kern/subr_prf.c:229
__assert(ffffffff833e0e6c,ffffffff83327d51,3b7,ffffffff833e10f4) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80003a92b618,ffffffff8333053a) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:952
pppx_if_destroy(ffff80002ccf4000,ffff80003a92b610) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794
pppxclose(205b92,41,2000,ffff80003c96a2c0) at pppxclose+0xa0 sys/net/if_pppx.c:541
spec_close(ffff80003692d8b0) at spec_close+0x412 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd806c50dce0,41,fffffd8007bfb5b0,ffff80003c96a2c0) at VOP_CLOSE+0x12a sys/kern/vfs_vops.c:156
vn_closefile(fffffd8067c6a080,ffff80003c96a2c0) at vn_closefile+0x11d vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd8067c6a080,ffff80003c96a2c0) at vn_closefile+0x11d sys/kern/vfs_vnops.c:615
fdrop(fffffd8067c6a080,ffff80003c96a2c0) at fdrop+0x126 sys/kern/kern_descrip.c:1267
closef(fffffd8067c6a080,ffff80003c96a2c0) at closef+0x18d sys/kern/kern_descrip.c:1251
syscall(ffff80003692db10) at syscall+0x97e mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003692db10) at syscall+0x97e sys/arch/amd64/amd64/trap.c:748
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f2923e5b60, count: 245
End of stack trace.