(RHSA-2017:0386) Important: kernel security, bug fix, and enhancement update

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• Linux kernel built with the Kernel-based Virtual Machine (CONFIG_KVM) support is vulnerable to a null pointer dereference flaw. It could occur on x86 platform, when emulating an undefined instruction. An attacker could use this flaw to crash the host kernel resulting in DoS. (CVE-2016-8630, Important)

• A race condition issue leading to a use-after-free flaw was found in the way the raw packet sockets implementation in the Linux kernel networking subsystem handled synchronization while creating the TPACKET_V3 ring buffer. A local user able to open a raw packet socket (requires the CAP_NET_RAW capability) could use this flaw to elevate their privileges on the system. (CVE-2016-8655, Important)

• A flaw was discovered in the Linux kernel’s implementation of VFIO. An attacker issuing an ioctl can create a situation where memory is corrupted and modify memory outside of the expected area. This may overwrite kernel memory and subvert kernel execution. (CVE-2016-9083, Important)

• The use of a kzalloc with an integer multiplication allowed an integer overflow condition to be reached in vfio_pci_intrs.c. This combined with CVE-2016-9083 may allow an attacker to craft an attack and use unallocated memory, potentially crashing the machine. (CVE-2016-9084, Moderate)

Red Hat would like to thank Philip Pettersson for reporting CVE-2016-8655.

Additional Changes:

Space precludes documenting all of the bug fixes and enhancements included in this advisory. To see the complete list of bug fixes and enhancements, refer to the following KnowledgeBase article: https://access.redhat.com/articles/2940041.