Bug 2532139 (CVE-2026-89710)

Summary: CVE-2026-89710 kernel: NFSv4.1: fix layout segment leak on the pnfs_layout_process() forget path
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 Linux kernel's NFSv4.1 implementation. When a server returns a new layout state identifier while an existing one is still active, the pnfs_layout_process() function fails to properly release memory associated with layout segments. This oversight leads to a memory leak, which could eventually result in a Denial of Service (DoS) condition for affected systems.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-11 20:53:35 UTC
In the Linux kernel, the following vulnerability has been resolved:

NFSv4.1: fix layout segment leak on the pnfs_layout_process() forget path

When the server returns a new layout stateid while a valid one is still
held, pnfs_layout_process() calls pnfs_mark_matching_lsegs_return() on
the on-stack free_me list and jumps to out_forget. Segments whose
reference count drops to zero are unlinked from lo->plh_segs and moved
to free_me by mark_lseg_invalid(); for an idle cached segment the layout
header holds the only reference, so this happens on the first decrement.

out_forget never drains free_me -- only the success path calls
pnfs_free_lseg_list().

Commit 814b84971388 ("pNFS/NFSv4: Fix a layout segment leak in
pnfs_layout_process()") added the drain; commit 08bd8dbe8882
("pNFS/NFSv4: Try to return invalid layout in pnfs_layout_process()")
removed it while switching the destination to lo->plh_return_segs, which
is drained elsewhere. Commit fb700ef02676 ("NFSv4.1: Simplify layout
return in pnfs_layout_process()") switched the destination back to
free_me without restoring the drain.

Restore the pnfs_free_lseg_list() call.