As far as I understand this is a bug in perf (userspace tool). This can
occur when running 'perf report' which has a generally short lived
lifespan. Is this really a CVE fix? What is the actual security threat?
Btw. CVE-2021-47545 is another one matcing the same pattern.
On Fri 24-05-24 17:10:03, Greg KH wrote:
> Description
> ===========
>
> In the Linux kernel, the following vulnerability has been resolved:
>
> perf report: Fix memory leaks around perf_tip()
>
> perf_tip() may allocate memory or use a literal, this means memory
> wasn't freed if allocated. Change the API so that literals aren't used.
>
> At the same time add missing frees for system_path. These issues were
> spotted using leak sanitizer.
>
> The Linux kernel CVE team has assigned CVE-2021-47543 to this issue.
>
>
> Affected and fixed versions
> ===========================
>
> Fixed in 5.4.164 with commit df5990db088d
> Fixed in 5.10.84 with commit ff061b5bda73
> Fixed in 5.15.7 with commit 71e284dcebec
> Fixed in 5.16 with commit d9fc706108c1
>
> Please see https://www.kernel.org for a full list of currently supported
> kernel versions by the kernel community.
>
> Unaffected versions might change over time as fixes are backported to
> older supported kernel versions. The official CVE entry at
> https://cve.org/CVERecord/?id=CVE-2021-47543
> will be updated if fixes are backported, please check that for the most
> up to date information about this issue.
>
>
> Affected files
> ==============
>
> The file(s) affected by this issue are:
> tools/perf/builtin-report.c
> tools/perf/util/util.c
> tools/perf/util/util.h
>
>
> Mitigation
> ==========
>
> The Linux kernel CVE team recommends that you update to the latest
> stable kernel version for this, and many other bugfixes. Individual
> changes are never tested alone, but rather are part of a larger kernel
> release. Cherry-picking individual commits is not recommended or
> supported by the Linux kernel community at all. If however, updating to
> the latest release is impossible, the individual changes to resolve this
> issue can be found at these commits:
> https://git.kernel.org/stable/c/df5990db088d4c7fea9a2f9b8195a7859e1768c4
> https://git.kernel.org/stable/c/ff061b5bda73c4f785b4703eeb0848fd99e5608a
> https://git.kernel.org/stable/c/71e284dcebecb9fd204ff11097469cc547723ad1
> https://git.kernel.org/stable/c/d9fc706108c15f8bc2d4ccccf8e50f74830fabd9
--
Michal Hocko
SUSE Labs
On Mon, Jun 10, 2024 at 10:34:04AM +0200, Michal Hocko wrote:
> As far as I understand this is a bug in perf (userspace tool). This can
> occur when running 'perf report' which has a generally short lived
> lifespan. Is this really a CVE fix? What is the actual security threat?
You are correct, now rejected.
> Btw. CVE-2021-47545 is another one matcing the same pattern.
Thank you for noticing, also now rejected.
greg k-h