CVE-2023-52486
Amazon Linux "{"drm" Double Unref " Bug
Description
In 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.
INFO
Published Date :
March 11, 2024, 6:15 p.m.
Last Modified :
June 27, 2024, 1:15 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
Exploitability Score :
References to Advisories, Solutions, and Tools
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information, practical solutions, and valuable tools related to
CVE-2023-52486.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2023-52486 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2023-52486 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 27, 2024
Action Type Old Value New Value Added Reference kernel.org https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html [No types assigned] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 25, 2024
Action Type Old Value New Value Added Reference kernel.org https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html [No types assigned] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 14, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Mar. 11, 2024
Action Type Old Value New Value Added Description In 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. Added Reference Linux https://git.kernel.org/stable/c/376e21a9e4c2c63ee5d8d3aa74be5082c3882229 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/9dd334a8245011ace45e53298175c7b659edb3e7 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/f55261469be87c55df13db76dc945f6bcd825105 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/b4af63da9d94986c529d74499fdfe44289acd551 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/62f2e79cf9f4f47cc9dea9cebdf58d9f7b5695e0 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/d7afdf360f4ac142832b098b4de974e867cc063c [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/bfd0feb1b109cb63b87fdcd00122603787c75a1a [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/cb4daf271302d71a6b9a7c01bd0b6d76febd8f0c [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2023-52486 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2023-52486
weaknesses.