Bug 2527992 - CVE-2026-71220 gfs2-utils: gfs2-utils: stack out-of-bounds write via unchecked di_height in gfs2_edit [fedora-all]
Summary: CVE-2026-71220 gfs2-utils: gfs2-utils: stack out-of-bounds write via unchecke...
Keywords:
Status: NEW
Alias: None
Product: Fedora
Classification: Fedora
Component: gfs2-utils
Version: rawhide
Hardware: Unspecified
OS: Unspecified
medium
medium
Target Milestone: ---
Assignee: Andrew Price
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["700f8c4c-dab0-44fb-8f9d-e...
Depends On:
Blocks: CVE-2026-71220
TreeView+ depends on / blocked
 
Reported: 2026-09-03 11:45 UTC by Samuele Negrini
Modified: 2026-09-03 11:45 UTC (History)
5 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Type: ---
Embargoed:


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Description Samuele Negrini 2026-09-03 11:45:32 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

A flaw was found in gfs2-utils. In the gfs2_edit tool, the metapath_to_lblock() function in extended.c uses the di_height field from on-disk inode metadata as an array index into a fixed-size stack array factor[GFS2_MAX_META_HEIGHT] (10 elements) without bounds validation. An attacker can craft a GFS2 filesystem image with di_height exceeding 10 (up to 65535) to write past the end of the array, corrupting adjacent stack memory including saved registers and the return address. The subsequent loop (factor[h] = factor[h+1] * sbd.sd_inptrs) amplifies the corruption by writing additional entries past the array boundary. This is a classic stack buffer overflow that may allow arbitrary code execution when gfs2_edit processes the crafted image. The Linux kernel GFS2 driver validates di_height against sd_max_height in gfs2_dinode_in(), but the userspace gfs2-utils performs no equivalent validation.


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