Bug 2511398 (CVE-2026-71220)

Summary: CVE-2026-71220 gfs2-utils: gfs2-utils: stack out-of-bounds write via unchecked di_height in gfs2_edit
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, security-response-team, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A stack out-of-bounds write vulnerability was found in gfs2-utils. In gfs2_edit, the di_height field from on-disk inode metadata is used as an array index without bounds checking, causing a stack buffer overflow that may lead to arbitrary code execution when processing crafted GFS2 filesystem images.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2527992    
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Description OSIDB Bzimport 2026-08-05 08:40:55 UTC 
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.