Ubuntu Security Notice USN-2516-2

Ubuntu Security Notice 2516-2 – USN-2516-1 fixed vulnerabilities in the Linux kernel. There was an unrelated regression in the use of the virtual counter (CNTVCT) on arm64 architectures. This update fixes the problem. A flaw was discovered in the Kernel Virtual Machine’s (KVM) emulation of the SYSTENTER instruction when the guest OS does not initialize the SYSENTER MSRs. A guest OS user could exploit this flaw to cause a denial of service of the guest OS (crash) or potentially gain privileges on the guest OS. Various other issues were also addressed.

Linux CVE-2014-9322 Proof Of Concept

arch/x86/kernel/entry_64.S in the Linux kernel before 3.17.5 does not properly handle faults associated with the Stack Segment (SS) segment register, which allows local users to gain privileges by triggering an IRET instruction that leads to access to a GS Base address from the wrong space. This is a POC to reproduce vulnerability. No exploitation here, just simple kernel panic.

Linux CVE-2014-3631 Proof Of Concept

The assoc_array_gc function in the associative-array implementation in lib/assoc_array.c in the Linux kernel before 3.16.3 does not properly implement garbage collection, which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via multiple “keyctl newring” operations followed by a “keyctl timeout” operation.