CVE-2026-46209: Linux kernel · drm/gem: Fix inconsistent plane dimension calculation in drm_gem_fb_init_with_funcs()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in c5fc49d8470c5ebf3b41607600f277158f159950 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in c5fc49d8470c5ebf3b41607600f277158f159950, adfc5ba4ef4dd2bca5969f40e8fc7b41fb3902ad, 22922f7dae74409fc4bf0f1142710cb6b8ce8cc2 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: drm/gem: Fix inconsistent plane dimension calculation in drm_gem_fb_init_with_funcs() drm_gem_fb_init_with_funcs() computes sub-sampled plane dimensions using plain integer division: unsigned int width = mode_cmd->width / (i ? info->hsub : 1); unsigned int height = mode_cmd->height / (i ? info->vsub : 1); However, the ioctl-level framebuffer_check() in drm_framebuffer.c uses drm_format_info_plane_width/height() which round up dimensions via DIV_ROUND_UP(). This inconsistency corrupts the subsequent GEM object size check for certain pixel format and dimension combinations. For example, with NV12 (vsub=2) and a 1-pixel-tall framebuffer the GEM size validation path sees height=0 instead of height=1. The expression (height - 1) then wraps to UINT_MAX as an unsigned int, causing min_size to overflow and wrap back to a small value. A tiny GEM object therefore passes the size guard, yet when the GPU accesses the chroma plane it will read or write memory beyond the object's bounds. Fix by replacing the open-coded divisions with drm_format_info_plane_width() and drm_format_info_plane_height(), which use DIV_ROUND_UP() and match the calculation already used in framebuffer_check().
References
- git.kernel.org/stable/c/11427ad6c9f0def5ce567982b785da3191946430 (opens in a new tab)
- git.kernel.org/stable/c/adfc5ba4ef4dd2bca5969f40e8fc7b41fb3902ad (opens in a new tab)
- git.kernel.org/stable/c/22922f7dae74409fc4bf0f1142710cb6b8ce8cc2 (opens in a new tab)
- git.kernel.org/stable/c/6b992591e04f2cce813bcf239b354f375bbf84d3 (opens in a new tab)
- git.kernel.org/stable/c/1da4ab7189f1064b3b712b388772c008b4d82580 (opens in a new tab)
- git.kernel.org/stable/c/1a17ea9861e89585361caa8bc231bd22dc6dbe7d (opens in a new tab)
- git.kernel.org/stable/c/c5fc49d8470c5ebf3b41607600f277158f159950 (opens in a new tab)
- git.kernel.org/stable/c/3d4c2268bd7243c3780fe32bf24ff876da272acf (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)