It was discovered that the cls_route filter implementation in the Linux kernel would not remove an old filter from the hashtable before freeing it if its handle had the value 0.
Exploitability
AV:LAC:HPR:LUI:NScope
S:UImpact
C:NI:LA:H5.3/CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:HMemory Safety