Bug 2507195 (CVE-2026-64357)

Summary: CVE-2026-64357 kernel: xfs: fix exchmaps reservation limit check
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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OS: Linux   
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Description OSIDB Bzimport 2026-07-25 10:10:00 UTC 
In the Linux kernel, the following vulnerability has been resolved:

xfs: fix exchmaps reservation limit check

xfs_exchmaps_estimate_overhead() adds the bmbt and rmapbt
overhead to a local resblks variable, but the final UINT_MAX
check still tests req->resblks.  That is the reservation value
from before the overhead was added.

The computed value is stored back in req->resblks and later passed
to xfs_trans_alloc(), whose block reservation argument is unsigned
int.  Check the computed reservation so the existing limit applies
to the value that will be used.
Comment 1 TEJ RATHI 2026-07-29 10:39:21 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072519-CVE-2026-64357-8c69@gregkh/T