panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 955
Starting stack trace...
panic(ffffffff8344aac0) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff8348ad45,ffffffff8349e607,3bb,ffffffff834c745c) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff80003c3f7148,ffffffff83442679) at refcnt_finalize+0x1db sys/kern/kern_synch.c:956
pppx_if_destroy(205b9a,ffff80003c3f7140) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794
pppxclose(205b9a,2,2000,ffff8000fffee018) at pppxclose+0xa0 sys/net/if_pppx.c:541
spec_close(ffff800034badc60) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd8060f28cf0,2,fffffd80097fd0d0,ffff8000fffee018) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd8064f83b48,ffff8000fffee018) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd8064f83b48,ffff8000fffee018) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd8064f83b48,ffff8000fffee018) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffffd8064f83b48,ffff8000fffee018) at closef+0x192 sys/kern/kern_descrip.c:1265
fdfree(ffff8000fffee018) at fdfree+0x116 sys/kern/kern_descrip.c:1196
exit1(ffff8000fffee018,0,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff8000fffee018,ffff800034badfd0,ffff800034badf20) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff800034badfd0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800034badfd0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x71016ee84a70, count: 242
End of stack trace.