CVE-2023-52486
MediumIn the Linux kernel, the following vulnerability has been resolved: drm: Don't unref the same fb many times by mistake due to deadlock handling If we get a deadlock after the fb lookup in drm_mode_page_flip_ioctl() we proceed to unref the fb and then retry the whole thing from the top. But we forget to reset the fb pointer back to NULL, and so if we then get another error during the retry, before the fb lookup, we proceed the unref the same fb again without having gotten another reference. The end result is that the fb will (eventually) end up being freed while it's still in use. Reset fb to NULL once we've unreffed it to avoid doing it again until we've done another fb lookup. This turned out to be pretty easy to hit on a DG2 when doing async flips (and CONFIG_DEBUG_WW_MUTEX_SLOWPATH=y). The first symptom I saw that drm_closefb() simply got stuck in a busy loop while walking the framebuffer list. Fortunately I was able to convince it to oops instead, and from there it was easier to track down the culprit.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-667CVE-2023-52486 is a Improper Locking vulnerability
What is Improper Locking?
The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE
Affected versions
Linux kernel versions
4.12
and later are affected. Fixed in
4.19.307,
5.4.269,
5.10.210,
5.15.149,
6.1.76,
6.6.15,
6.7.3,
6.8
and their respective stable series.
References
10 total-
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Frequently asked questions
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What is CVE-2023-52486?
CVE-2023-52486 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Improper Locking flaw (CWE-667) . It affects Linux kernel versions from 4.12 onward and has been patched in 4.19.307, 5.4.269, 5.10.210 and others. CVE-2023-52486 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2023-52486?
CVE-2023-52486 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2023-52486?
Yes. CVE-2023-52486 has been patched. Fixed versions include 4.19.307, 5.4.269, 5.10.210 and others. If you are running Linux kernel 4.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2023-52486 actively exploited?
No. CVE-2023-52486 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.