【CESA-2017:1308】An update for kernel is now available for Red Hat Enterprise Linux 7


An update for kernel is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of
Important. A Common Vulnerability Scoring System (CVSS) base score, which gives
a detailed severity rating, is available for each vulnerability from the CVE
link(s) in the References section.

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

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,

* 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,

Red Hat would like to thank Igor Redko (Virtuozzo kernel team) for reporting

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.

Bugs Fixed

1388821 – CVE-2016-8646 kernel: Oops in shash_async_export()
1395190 – CVE-2016-10208 kernel: EXT4 memory corruption / SLAB out-of-bounds read
1399727 – CVE-2016-7910 kernel: Use after free in seq file
1420276 – CVE-2017-5986 kernel: Reachable BUG_ON from userspace in sctp_wait_for_sndbuf
1437404 – CVE-2017-7308 kernel: net/packet: overflow in check for priv area size