CVE-2009-0778: High severity Linux Linux kernel vulnerability

Created attachment 331637 [details] ipdstcache (in blue) VS route -Cn | wc -l (in green) over time

Description of problem: The value of ipdstcache (in /proc/slabinfo) continues to grow constantly, even thought the cached route table remains fairly constant. This leads to the eventual time when ipdstcache reaches the value of /proc/sys/net/ipv4/route/maxsize. When this happens, the kernel complains with 'dst cache overflow' and the server no longer responds to any network activity.

Version-Release number of selected component (if applicable): kernel 2.6.18-92.1.22.el5

How reproducible: live system being currently affected by this issue.

Steps to Reproduce: 1. Configure test machine as a router between two networks 2. send packets from network A to network B with a large number of different source/dest IPs 3. Watch the values of ipdstcache and rtcache Actual results: ipdstcache continues to grow while rtcache grows and shrinks with the traffic

Expected results: ipdstcache and rtcache follow each other closely. Values return to zero after traffic stops and route cache entries expire.

Additional info: