Bug 2502559 (CVE-2026-64157)

Summary: CVE-2026-64157 kernel: netfs: Fix partial invalidation of streaming-write folio
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, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's network file system (netfs) component. This vulnerability allows for incorrect handling of data during partial invalidation operations on streaming-write pages. An attacker could potentially exploit this to cause data corruption or unexpected system behavior, impacting data integrity.
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Description OSIDB Bzimport 2026-07-19 17:06:05 UTC 
In the Linux kernel, the following vulnerability has been resolved:

netfs: Fix partial invalidation of streaming-write folio

In netfs_invalidate_folio(), if the region of a partial invalidation
overlaps the front (but not all) of a dirty write cached in a streaming
write page (dirty, but not uptodate, with the dirty region tracked by a
netfs_folio struct), the function modifies the dirty region - but
incorrectly as it moves the region forward by setting the start to the
start, not the end, of the invalidation region.

Fix this by setting finfo->dirty_offset to the end of the invalidation
region (iend).
Comment 1 TEJ RATHI 2026-07-20 11:42:52 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026071933-CVE-2026-64157-8f76@gregkh/T