drm: Don't unref the same fb many times by mistake due to deadlock handling (Linux Linux)

CVE-2023-52486
HIGH 7.8

At a glance

Source
NVD
EPSS
EPSS 0.23 % · percentile 14 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

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.

Weaknesses (CWE)

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 29dc0d1de18239cf3ef8bab578b8321ed340d81c < 376e21a9e4c2c63ee5d8d3aa74be5082c3882229 ; affected 29dc0d1de18239cf3ef8bab578b8321ed340d81c < 9dd334a8245011ace45e53298175c7b659edb3e7 ; affected 29dc0d1de18239cf3ef8bab578b8321ed340d81c < f55261469be87c55df13db76dc945f6bcd825105 ; affected 29dc0d1de18239cf3ef8bab578b8321ed340d81c < b4af63da9d94986c529d74499fdfe44289acd551 ; affected 29dc0d1de18239cf3ef8bab578b8321ed340d81c < 62f2e79cf9f4f47cc9dea9cebdf58d9f7b5695e0 ; affected 29dc0d1de18239cf3ef8bab578b8321ed340d81c < d7afdf360f4ac142832b098b4de974e867cc063c
Linux · Linuxaffected 4.12 ; unaffected 0 < 4.12 ; unaffected 4.19.307 ≤ 4.19.* ; unaffected 5.4.269 ≤ 5.4.* ; unaffected 5.10.210 ≤ 5.10.* ; unaffected 5.15.149 ≤ 5.15.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD