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CVE-2026-46209

drm/gem: Fix inconsistent plane dimension calculation in drm_gem_fb_init_with_funcs()

At a glance

Severity
HIGH 7.8
EPSS
EPSS 0.14 % · percentile 3 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

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().

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)

Weaknesses (CWE)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 4c3dbb2c312c9fafbac30d98c523b8b1f3455d78 < 11427ad6c9f0def5ce567982b785da3191946430 ; affected 4c3dbb2c312c9fafbac30d98c523b8b1f3455d78 < adfc5ba4ef4dd2bca5969f40e8fc7b41fb3902ad ; affected 4c3dbb2c312c9fafbac30d98c523b8b1f3455d78 < 22922f7dae74409fc4bf0f1142710cb6b8ce8cc2 ; affected 4c3dbb2c312c9fafbac30d98c523b8b1f3455d78 < 6b992591e04f2cce813bcf239b354f375bbf84d3 ; affected 4c3dbb2c312c9fafbac30d98c523b8b1f3455d78 < 1da4ab7189f1064b3b712b388772c008b4d82580 ; affected 4c3dbb2c312c9fafbac30d98c523b8b1f3455d78 < 1a17ea9861e89585361caa8bc231bd22dc6dbe7d
Linux · Linuxaffected 4.14 ; unaffected 0 < 4.14 ; unaffected 5.10.258 ≤ 5.10.* ; unaffected 5.15.209 ≤ 5.15.* ; unaffected 6.1.175 ≤ 6.1.* ; unaffected 6.6.140 ≤ 6.6.*

References

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