panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 955
Starting stack trace...
panic(ffffffff833af0f2) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff833ef65b,ffffffff83400622,3bb,ffffffff8342a2b2) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80003bbf74f0,ffffffff833a9894) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956
pppx_if_destroy(ffff80002e7bd000,ffff80003bbf74e8) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794
pppxclose(205b9a,2,2000,ffff8000fffe8020) at pppxclose+0xa0 sys/net/if_pppx.c:541
spec_close(ffff80003c47b820) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd8062c603b0,2,fffffd80097fd4e0,ffff8000fffe8020) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806c7717d0,ffff8000fffe8020) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd806c7717d0,ffff8000fffe8020) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd806c7717d0,ffff8000fffe8020) at fdrop+0x121 sys/kern/kern_descrip.c:1280
closef(fffffd806c7717d0,ffff8000fffe8020) at closef+0x192 sys/kern/kern_descrip.c:1264
finishdup(ffff8000fffe8020,fffffd806c7712d0,4,6,ffff80003c47ba80,2) at finishdup+0x478 sys/kern/kern_descrip.c:688
syscall(ffff80003c47bb30) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c47bb30) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xdbf2be73e70, count: 244
End of stack trace.