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:
The VMware vCenter Server contains an out-of-bounds read vulnerability in the implementation of the DCERPC protocol. A malicious actor with network access to vCenter Server may trigger an out-of-bounds read by sending a specially crafted packet leading to denial-of-service of certain services (vmcad, vmdird, and vmafdd).
VMware vCenter Server 4.0 before Update 4b, 5.0 before Update 2, and 5.1 before 5.1.0b; VMware ESXi 3.5 through 5.1; and VMware ESX 3.5 through 4.1 do not properly implement the Network File Copy (NFC) protocol, which allows man-in-the-middle attackers to execute arbitrary code or cause a denial of service (memory corruption) by modifying the client-server data stream.
Tavis Ormandy and Julien Tinnes, Google Security Team reported that Kernels <= 2.6.18.8 are vulnerable to a NULL pointer dereference issue when using MSGMORE on udp sockets.
Fixed upstream already by: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=1e0c14f49d6b393179f423abbac47f85618d3d46
Acknowledgements:
Red Hat would like to thank Tavis Ormandy and Julien Tinnes of the Google Security Team for responsibly reporting this flaw.