ring-buffer: Check for NULL cpu_buffer in ring_buffer_wake_w…(CVE-2022-49889)

概要

ring-buffer: Check for NULL cpu_buffer in ring_buffer_wake_waiters()

原文の説明

取得元が公開している説明をそのまま載せています (多くは英語)。

In the Linux kernel, the following vulnerability has been resolved:

ring-buffer: Check for NULL cpu_buffer in ring_buffer_wake_waiters()

On some machines the number of listed CPUs may be bigger than the actual
CPUs that exist. The tracing subsystem allocates a per_cpu directory with
access to the per CPU ring buffer via a cpuX file. But to save space, the
ring buffer will only allocate buffers for online CPUs, even though the
CPU array will be as big as the nr_cpu_ids.

With the addition of waking waiters on the ring buffer when closing the
file, the ring_buffer_wake_waiters() now needs to make sure that the
buffer is allocated (with the irq_work allocated with it) before trying to
wake waiters, as it will cause a NULL pointer dereference.

While debugging this, I added a NULL check for the buffer itself (which is
OK to do), and also NULL pointer checks against buffer->buffers (which is
not fine, and will WARN) as well as making sure the CPU number passed in
is within the nr_cpu_ids (which is also not fine if it isn't).

Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=1204705

出典: OSV.dev (Open Source Vulnerabilities) NVD OSV

影響パッケージ

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"5.15.75"},{"fixed":"5.15.78"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.0.3"},{"fixed":"6.0.8"}]}]

ディストリビューション別の修正状況

各ディストリビューションが公開している、この CVE の修正パッケージ

Debian DEBIAN-CVE-2022-49889 linux 修正版: 6.0.8-1

概要

原文の説明

影響パッケージ

ディストリビューション別の修正状況

参照URL