(RHSA-2017:1308) 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):

• It was found that the packet_set_ring() function of the Linux kernel’s networking implementation did not properly validate certain block-size data. A local attacker with CAP_NET_RAW capability could use this flaw to trigger a buffer overflow, resulting in the crash of the system. Due to the nature of the flaw, privilege escalation cannot be fully ruled out. (CVE-2017-7308, Important)

• Mounting a crafted EXT4 image read-only leads to an attacker controlled memory corruption and SLAB-Out-of-Bounds reads. (CVE-2016-10208, Moderate)

• A flaw was found in the Linux kernel’s implementation of seq_file where a local attacker could manipulate memory in the put() function pointer. This could lead to memory corruption and possible privileged escalation. (CVE-2016-7910, Moderate)

• A vulnerability was found in the Linux kernel. An unprivileged local user could trigger oops in shash_async_export() by attempting to force the in-kernel hashing algorithms into decrypting an empty data set. (CVE-2016-8646, Moderate)

• It was reported that with Linux kernel, earlier than version v4.10-rc8, an application may trigger a BUG_ON in sctp_wait_for_sndbuf if the socket tx buffer is full, a thread is waiting on it to queue more data, and meanwhile another thread peels off the association being used by the first thread. (CVE-2017-5986, Moderate)

Red Hat would like to thank Igor Redko (Virtuozzo kernel team) for reporting CVE-2016-8646.

Additional Changes:

This update also fixes several bugs and adds various enhancements. Documentation for these changes is available from the Technical Notes document linked to in the References section.