Serious bugs in RedHatLinux will affect Servers Based on Haswell Architecture

Recently, AzulSystems CTO and co-founder GilTene reported a very important issue at GoogleGroups, but little-known Linux Kernel patches, especially for Linux system users and administrators using Intel Haswell architecture. In particular, users based on the RedHat release version (including CentOS6.6 and ScientificLinux6.6) should update this patch immediately. Even if

Recently, CTO of Azul Systems and co-founder Gil Tene reported a very important but little-known Linux kernel patch at Google Groups, users and administrators of Linux systems using Intel Haswell architecture should pay special attention to this issue. This patch should be updated immediately, especially for Red Hat-based users (including CentOS 6.6 and Scientific Linux 6.6. Even Linux running on a virtual machine, if the virtual machine is on a popular cloud platform (such as Azure and Amazon), it may also run on Haswell machines. Patching should be advantageous.

Tene describes the defect as follows:

"The impact of this kernel vulnerability is very simple: in some seemingly impossible situations, user processes will be deadlocked and suspended. Any futex call wait (even if it is correctly awakened) may always be blocked for execution. Just as Thread. park () in Java may be congested all the time, and so on. If you are lucky enough, you will find the soft lockup message in the dmesg log; if you are not so lucky (such as with us ), you will have to spend several months manually investigating problems in the code, and you may have nothing to gain."

Tene continues to explain how the code with this defect is executed (eventually a switch block with default missing ). The biggest problem now is that, although the problem code was fixed in January 2014, it was moved back to the Red Hat October 2014 family system around 6.6. Other systems, including SLES, Ubuntu, and Debian, may also be affected.

These System fixes are currently inconsistent and may be ignored. Red Hat users should use RHEL 6.6.z or an updated version. Tene also points out that different releases have different options for what to put into the kernel, which leads to inconsistent fixes.

For example, for RHEL 7.1, "In fact, the upstream 3.10 kernel does not have this bug, but the RHEL 7 kernel is not a pure upstream version. Unfortunately, RHEL 7.1 (just like RHEL 6.6) included the (based on RHEL 7) bug During porting ...... I think other releases may do the same."

Tene provides a quick reference list for RHEL-based releases:

RHEL 5 (including CentOS 5 and Scientific Linux 5): No problem with all versions (including version 5.11.

RHEL 6 (including CentOS 6 and Scientific Linux 6): from 6.0 ~ Version 6.5 is okay. However, version 6.6 is defective, and version 6.6.z is normal.

RHEL 7 (including CentOS 7 and Scientific Linux 7): 7.1 is defective. As of January 1, May 13, 2015, there was no 7.x fix.

Although there are some disputes over the number of affected systems on Hacker News, it provides some environments to check whether your system needs to be repaired.

Editor's note: It will take place from January 1, October 15, 2015 ~ At the QCon Shanghai 2015 Conference held on the 17th, Azul Systems co-founder and CTO Gil Tene will give a keynote speech. He is a famous Java and JVM expert. If you sign up before January 1, you will receive a discount.

For more information about RedHat, see RedHat topic page http://www.linuxidc.com/topicnews.aspx? Tid = 10

Serious Red Hat Linux Bug Affects Haswell-based Servers

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