Bug 2532403 (CVE-2026-89602)

Summary: CVE-2026-89602 kernel: erofs: skip sufficiently large global buffers when resizing
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the `erofs` (Enhanced Read-Only File System) component of the Linux kernel. This vulnerability occurs when resizing global buffers, specifically if a resize operation fails after some buffers have already been enlarged. A subsequent retry can lead to memory corruption by attempting to copy more data than an allocated buffer can hold. Additionally, retrying with the same size can result in an out-of-memory error, causing a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-11 22:48:38 UTC
In the Linux kernel, the following vulnerability has been resolved:

erofs: skip sufficiently large global buffers when resizing

z_erofs_gbuf_nrpages is advanced only after every global buffer has been
grown. If a resize fails after some buffers were enlarged, a retry
revisits those enlarged buffers.

Retrying the same size then returns -ENOMEM because alloc_pages_bulk()
has no pages to add and the unchanged return value is treated as a
failure. Retrying an intermediate size allocates a temporary pointer
array smaller than gbuf->nrpages and copies more existing pointers than
the array can hold.

Skip buffers that already satisfy the request. Once all remaining
buffers have caught up, advancing z_erofs_gbuf_nrpages again describes
the guaranteed minimum size across the pool.