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Arronical
Asked: 2015-10-08 02:14:53 +0800 CST

How do kernel updates differ from kernel upgrades?

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Today I ran:

apt-get update
apt-get dist-upgrade

And noticed that the following packages were upgraded:

linux-headers-3.13.0-65-generic:i386
linux-image-3.13.0-65-generic:i386
linux-image-extra-3.13.0-65-generic:i386
linux-headers-3.13.0-65:i386

I know that these are updates to the kernel, and checked the /var/log/apt/history file, finding these lines:

linux-headers-3.13.0-65-generic:i386 (3.13.0-65.105, 3.13.0-65.106)
linux-image-3.13.0-65-generic:i386 (3.13.0-65.105, 3.13.0-65.106)
linux-image-extra-3.13.0-65-generic:i386 (3.13.0-65.105, 3.13.0-65.106)
linux-headers-3.13.0-65:i386 (3.13.0-65.105, 3.13.0-65.106)

I figure that this is telling me it's upgraded from the 105 to the 106 build, and assume it's in relation to CVE-2015-7613.

Why does this get released as an upgrade rather than becoming 3.13.0-66? I noticed some very quick jumps in kernel (minor?) releases a couple of weeks ago, and am curious as to how this is governed.

apt

1 Answers

  1. Best Answer

    The kernel version numbers are constructed as follows:

    <base kernel version>-<ABI number>.<upload number>

    Whenever there is an ABI change in the kernel the ABI number is incremented. An ABI change can happen for example when: a structure changes, a function prototypes changes, or system calls are added. If there is a new build in which the ABI doesn't change, the upload number may only be incremented. This occurs sometimes when an important CVE needs to be fixed or the kernel is rebuilt due to a regression.

    Source:

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