panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 959
Starting stack trace...
panic(ffffffff834bc0cd) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff834f9dac,ffffffff8350d2a8,3bf,ffffffff83536171) at __assert+0x29 sys/kern/subr_prf.c:-1
refcnt_finalize(ffff800034397770,ffffffff834aee3f) at refcnt_finalize+0x1e7 sys/kern/kern_synch.c:960
pppx_if_destroy(205b9a,ffff800034397768) at pppx_if_destroy+0x3d sys/net/if_pppx.c:794
pppxclose(205b9a,81,2000,ffff80002a223c98) at pppxclose+0xa0 sys/net/if_pppx.c:541
spec_close(ffff80002a2662c0) at spec_close+0x417 sys/kern/spec_vnops.c:-1
VOP_CLOSE(ffffef806fdad1c0,81,ffffef80097fd548,ffff80002a223c98) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(ffffef806fb67c88,ffff80002a223c98) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(ffffef806fb67c88,ffff80002a223c98) at vn_closefile+0x12b sys/kern/vfs_vnops.c:621
fdrop(ffffef806fb67c88,ffff80002a223c98) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(ffffef806fb67c88,ffff80002a223c98) at closef+0x192 sys/kern/kern_descrip.c:1265
fdfree(ffff80002a223c98) at fdfree+0x116 sys/kern/kern_descrip.c:1196
exit1(ffff80002a223c98,0,0,1) at exit1+0x595 sys/kern/kern_exit.c:215
sys_exit(ffff80002a223c98,ffff80002a266630,ffff80002a266580) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff80002a266630) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a266630) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x75cf4b517550, count: 242
End of stack trace.
syncing disks...