Bug 2527995

Summary: CVE-2026-71222 gfs2-utils: gfs2-utils: heap out-of-bounds read via unchecked ea_num_ptrs in extended attribute processing [fedora-all]
Product: [Fedora] Fedora Reporter: Samuele Negrini <snegrini>
Component: gfs2-utilsAssignee: Andrew Price <anprice>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: agk, agruenba, anprice, bmarzins, cfeist
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["efe44676-de2e-47d2-bd24-678c0e7d60ea"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2511399    

Description Samuele Negrini 2026-09-03 11:51:58 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. The ea_num_ptrs field from on-disk extended attribute metadata is used as a loop count in savemeta.c and metawalk.c without bounds validation. The ea_num_ptrs field is a __u8 (max 255). Each iteration reads a pointer (8 bytes) plus name data. With ea_num_ptrs=255 and a 512-byte block buffer, the loop reads up to 1384 bytes past the buffer boundary, causing a heap out-of-bounds read. This may disclose sensitive heap memory contents through tool output or error messages, and the significant over-read (2.7x the allocation) has a non-trivial probability of crossing a page boundary into unmapped memory, causing a crash.