CVE-2023-52486: drm: Don't unref the same fb many times by mistake due to deadlock handling
Vulnerability summary
CVE-2023-52486 is a high (CVSS 7.8) Improper Locking vulnerability in linux. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.8% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 30 · Related 24Timeline
- 29-02-2024PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
0.23%
Chance of exploitation in the next 30 days
Percentile
14%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.23% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu115 products
- linux< 4.15.0-232.244 | < 5.4.0-181.201 | < 5.15.0-106.116
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 4.15.0-1176.189 | < 5.4.0-1124.134 | < 5.15.0-1061.67
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 29dc0d1de18239cf3ef8bab578b8321ed340d81c, < 376e21a9e4c2c63ee5d8d3aa74be5082c3882229 | ≥ 29dc0d1de18239cf3ef8bab578b8321ed340d81c, < 9dd334a8245011ace45e53298175c7b659edb3e7 | ≥ 29dc0d1de18239cf3ef8bab578b8321ed340d81c, < f55261469be87c55df13db76dc945f6bcd825105 | ≥ 29dc0d1de18239cf3ef8bab578b8321ed340d81c, < b4af63da9d94986c529d74499fdfe44289acd551 | ≥ 29dc0d1de18239cf3ef8bab578b8321ed340d81c, < 62f2e79cf9f4f47cc9dea9cebdf58d9f7b5695e0 | ≥ 29dc0d1de18239cf3ef8bab578b8321ed340d81c, < d7afdf360f4ac142832b098b4de974e867cc063c | ≥ 29dc0d1de18239cf3ef8bab578b8321ed340d81c, < bfd0feb1b109cb63b87fdcd00122603787c75a1a | ≥ 29dc0d1de18239cf3ef8bab578b8321ed340d81c, < cb4daf271302d71a6b9a7c01bd0b6d76febd8f0c | 4.12
- linux_kernel< 4.19.307 | ≥ 4.20, < 5.4.269 | ≥ 5.5, < 5.10.210 | ≥ 5.11, < 5.15.149 | ≥ 5.16, < 6.1.76 | ≥ 6.2, < 6.6.15 | ≥ 6.7, < 6.7.3
Debian1 product
- linux< 6.1.76-1 | < 6.6.15-1
3 vendors · 118 products
