Synopsis

Important: kernel-rt security and bug fix update

Type/Severity

Security Advisory: Important

Topic

An update for kernel-rt 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.

Description

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

• A use-after-free vulnerability was found in the kernel's socket recvmmsg subsystem. This may allow remote attackers to corrupt memory and may allow execution of arbitrary code. This corruption takes place during the error handling routines within __sys_recvmmsg() function. (CVE-2016-7117, Important)
  
• A use-after-free vulnerability was found in tcp_xmit_retransmit_queue and other tcp_* functions. This condition could allow an attacker to send an incorrect selective acknowledgment to existing connections, possibly resetting a connection. (CVE-2016-6828, Moderate)
  
• A flaw was found in the Linux kernel's implementation of sctp protocol in which a remote attacker can trigger an out of bounds read with an offset of up to 64kB. This may panic the machine with a page-fault. (CVE-2016-9555, Moderate)
  

Bug Fix(es):

• The kernel-rt packages have been upgraded to the 3.10.0-514.6.1 source tree, which provides a number of bug fixes over the previous version. (BZ#1401863)
  
• Previously, the device mapper (DM) subsystem was not notified that the real-time kernel changes the way preemption works with spinlocks. This caused a kernel panic when the dm-multipath kernel module was loaded because the interrupt request (IRQ) check was invalid on the real-time kernel. This check has been corrected enabling the system to boot correctly with the dm-multipath module enabled. (BZ#1400930)
  
• Unlike the standard Linux kernel, the real-time kernel does not disable interrupts inside the Interrupt Service Routines driver. Because of this difference, a New API (NAPI) function for turning interrupt requests (IRQ) off was actually being called with IRQs enabled. Consequently, the NAPI poll list was being corrupted, causing improper networking card operation and potential kernel hangs. With this update, the NAPI function has been corrected to force modifications of the poll list to be protected allowing proper operation of the networking card drivers. (BZ#1402837)

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.

Affected Products

• Red Hat Enterprise Linux for Real Time 7 x86_64
• Red Hat Enterprise Linux for Real Time for NFV 7 x86_64

Fixes

• BZ - 1367091 - CVE-2016-6828 kernel: Use after free in tcp_xmit_retransmit_queue
• BZ - 1382268 - CVE-2016-7117 kernel: Use-after-free in the recvmmsg exit path
• BZ - 1397930 - CVE-2016-9555 kernel: Slab out-of-bounds access in sctp_sf_ootb()
• BZ - 1400930 - RT kernel panics with dm-multipath enabled
• BZ - 1401863 - kernel-rt: update to the RHEL7.3.z batch#2 source tree

CVEs

• CVE-2016-6828
• CVE-2016-7117
• CVE-2016-9555

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/7.3_Release_Notes/index.html

Red Hat Enterprise Linux for Real Time 7

SRPM
kernel-rt-3.10.0-514.6.1.rt56.429.el7.src.rpm	SHA-256: 0313ca98cbcffe5c624961354560e30bffc668e8886f006dbc26606c0df57dc8
x86_64
kernel-rt-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: d5c93a0cc7a0642d5180745d381372ab01ce27a0ccd9b9e6b8241d053d8c07f6
kernel-rt-debug-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 2a1e4e2876cd18b4a3fdfcec324f5c2a4091a5eb3de1851698aa68afb6dd540e
kernel-rt-debug-debuginfo-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 52a3074b4bfb40491948b669c9e7308ca488993c6caf3d17964f2d2eb7649b75
kernel-rt-debug-devel-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: b910e0c813aa9e38d5142c624c6737b151f0fa2b43d3c044ee727de196bae398
kernel-rt-debuginfo-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: b97076d22f50799ca2ca51e2e7be4ba0cc0915226b30464527f40e424700fdc8
kernel-rt-debuginfo-common-x86_64-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: d9f8a775a335d7b0582b5eefc7321440b584cc16c0074230e98e44403c13cba4
kernel-rt-devel-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: ffacf86475a12bd2daa84402146b5ed4ce9ec43780528d6f06f6812cf3f8a75d
kernel-rt-doc-3.10.0-514.6.1.rt56.429.el7.noarch.rpm	SHA-256: 50e2e0cee48bcd1c608dcb43bd9625f8848f57c7a48e73edfdfda843b3e645f2
kernel-rt-trace-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 3b3c305f16c2dabef9154af3e776f392642941c6cb385c54a5f0157c0fbcf309
kernel-rt-trace-debuginfo-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 37ef9229f968a5c8a6e88346e196f5568fe8e43be8e2520894610be057b45160
kernel-rt-trace-devel-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 371b234e1dda8889ee70d5725a337626cb7aabd8049c9c6a4f8ed79bd45655b4

Red Hat Enterprise Linux for Real Time for NFV 7

SRPM
kernel-rt-3.10.0-514.6.1.rt56.429.el7.src.rpm	SHA-256: 0313ca98cbcffe5c624961354560e30bffc668e8886f006dbc26606c0df57dc8
x86_64
kernel-rt-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: d5c93a0cc7a0642d5180745d381372ab01ce27a0ccd9b9e6b8241d053d8c07f6
kernel-rt-debug-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 2a1e4e2876cd18b4a3fdfcec324f5c2a4091a5eb3de1851698aa68afb6dd540e
kernel-rt-debug-debuginfo-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 52a3074b4bfb40491948b669c9e7308ca488993c6caf3d17964f2d2eb7649b75
kernel-rt-debug-devel-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: b910e0c813aa9e38d5142c624c6737b151f0fa2b43d3c044ee727de196bae398
kernel-rt-debug-kvm-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 0d8af2537da85a5ed370fac561534bdd2830fa6375f37efd43f6c9b480c5904e
kernel-rt-debug-kvm-debuginfo-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 6015acc807199a83b563c189c6e25e0eb574ac17a2b25bd74fd350c202a6a552
kernel-rt-debuginfo-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: b97076d22f50799ca2ca51e2e7be4ba0cc0915226b30464527f40e424700fdc8
kernel-rt-debuginfo-common-x86_64-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: d9f8a775a335d7b0582b5eefc7321440b584cc16c0074230e98e44403c13cba4
kernel-rt-devel-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: ffacf86475a12bd2daa84402146b5ed4ce9ec43780528d6f06f6812cf3f8a75d
kernel-rt-doc-3.10.0-514.6.1.rt56.429.el7.noarch.rpm	SHA-256: 50e2e0cee48bcd1c608dcb43bd9625f8848f57c7a48e73edfdfda843b3e645f2
kernel-rt-kvm-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 612d8e6587170f47e29f23118eafc3c07415c3b383cf84ca95457813ec1dc81e
kernel-rt-kvm-debuginfo-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 5e29adb04675dbdd6d19fb714f361736f86604279453131378fb1190e3c0b00f
kernel-rt-trace-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 3b3c305f16c2dabef9154af3e776f392642941c6cb385c54a5f0157c0fbcf309
kernel-rt-trace-debuginfo-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 37ef9229f968a5c8a6e88346e196f5568fe8e43be8e2520894610be057b45160
kernel-rt-trace-devel-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 371b234e1dda8889ee70d5725a337626cb7aabd8049c9c6a4f8ed79bd45655b4
kernel-rt-trace-kvm-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 0997426c89540e062b763bb7d1dc5d19ad18a3dcfa8959ae258026fa705eefa9
kernel-rt-trace-kvm-debuginfo-3.10.0-514.6.1.rt56.429.el7.x86_64.rpm	SHA-256: 80a795c38b9680f854cae47cf66947f03d9cef16b90f68c61f5ecb5459e3e706