7.8 - RHSA-2015:0102

Problem Description:

Updated kernel packages that fix multiple security issues and several bugs are now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having Important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Client (v. 7) - noarch, x86_64 Red Hat Enterprise Linux Client Optional (v. 7) - noarch, x86_64 Red Hat Enterprise Linux ComputeNode (v. 7) - noarch, x86_64 Red Hat Enterprise Linux ComputeNode Optional (v. 7) - noarch, x86_64 Red Hat Enterprise Linux Server (v. 7) - noarch, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 7) - noarch, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 7) - noarch, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 7) - noarch, x86_64

3. Description:

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

* A flaw was found in the way the Linux kernel's SCTP implementation validated INIT chunks when performing Address Configuration Change (ASCONF). A remote attacker could use this flaw to crash the system by sending a specially crafted SCTP packet to trigger a NULL pointer dereference on the system. (CVE-2014-7841, Important)

* A race condition flaw was found in the way the Linux kernel's mmap(2), madvise(2), and fallocate(2) system calls interacted with each other while operating on virtual memory file system files. A local user could use this flaw to cause a denial of service. (CVE-2014-4171, Moderate)

* A NULL pointer dereference flaw was found in the way the Linux kernel's Common Internet File System (CIFS) implementation handled mounting of file system shares. A remote attacker could use this flaw to crash a client system that would mount a file system share from a malicious server. (CVE-2014-7145, Moderate)

* A flaw was found in the way the Linux kernel's splice() system call validated its parameters. On certain file systems, a local, unprivileged user could use this flaw to write past the maximum file size, and thus crash the system. (CVE-2014-7822, Moderate)

* It was found that the parse_rock_ridge_inode_internal() function of the Linux kernel's ISOFS implementation did not correctly check relocated directories when processing Rock Ridge child link (CL) tags. An attacker with physical access to the system could use a specially crafted ISO image to crash the system or, potentially, escalate their privileges on the system. (CVE-2014-5471, CVE-2014-5472, Low)

Red Hat would like to thank Akira Fujita of NEC for reporting the CVE-2014-7822 issue. The CVE-2014-7841 issue was discovered by Liu Wei of Red Hat.

This update also fixes the following bugs:

* Previously, a kernel panic could occur if a process reading from a locked NFS file was killed and the lock was not released properly before the read operations finished. Consequently, the system crashed. The code handling file locks has been fixed, and instead of halting, the system now emits a warning about the unreleased lock. (BZ#1172266)

* A race condition in the command abort handling logic of the ipr device driver could cause the kernel to panic when the driver received a response to an abort command prior to receiving other responses to the aborted command due to the support for multiple interrupts. With this update, the abort handler waits for the aborted command's responses first before completing an abort operation. (BZ#1162734)

* Previously, a race condition could occur when changing a Page Table Entry (PTE) or a Page Middle Directory (PMD) to "pte_numa" or "pmd_numa", respectively, causing the kernel to crash. This update removes the BUG_ON() macro from the __handle_mm_fault() function, preventing the kernel panic in the aforementioned scenario. (BZ#1170662)

All kernel users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.

4. Solution:

Before applying this update, make sure all previously released errata relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at https://access.redhat.com/articles/11258

To install kernel packages manually, use "rpm -ivh [package]". Do not use "rpm -Uvh" as that will remove the running kernel binaries from your system. You may use "rpm -e" to remove old kernels after determining that the new kernel functions properly on your system.

5. Bugs fixed (https://bugzilla.redhat.com/):

1111180 - CVE-2014-4171 Kernel: mm/shmem: denial of service 1134099 - CVE-2014-5471 CVE-2014-5472 kernel: isofs: unbound recursion when processing relocated directories 1147522 - CVE-2014-7145 Kernel: cifs: NULL pointer dereference in SMB2_tcon 1163087 - CVE-2014-7841 kernel: net: sctp: NULL pointer dereference in af->from_addr_param on malformed packet 1163792 - CVE-2014-7822 kernel: splice: lack of generic write checks