CVE-2026-64519: NFSD: Fix infinite loop in layout state revocation

From: Greg Kroah-Hartman <[email protected]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

NFSD: Fix infinite loop in layout state revocation

find_one_sb_stid() skips stids whose sc_status is non-zero, but the
SC_TYPE_LAYOUT case in nfsd4_revoke_states() never sets sc_status
before calling nfsd4_close_layout(). The retry loop therefore finds
the same layout stid on every iteration, hanging the revoker
indefinitely.

The Linux kernel CVE team has assigned CVE-2026-64519 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.9 with commit 1e33e1414bec54a4feafa9e67e2617031be0afe2 and fixed in 6.12.92 with commit d1fc00ec02e9deb3f8d2bd59caf938c554fbc576
	Issue introduced in 6.9 with commit 1e33e1414bec54a4feafa9e67e2617031be0afe2 and fixed in 6.18.34 with commit fe59ae27d7346245f5d8d97220f374e63efd28b5
	Issue introduced in 6.9 with commit 1e33e1414bec54a4feafa9e67e2617031be0afe2 and fixed in 7.0.11 with commit 44e5e4eb3a07bf3e1d931dd9f96f3edcfa376605
	Issue introduced in 6.9 with commit 1e33e1414bec54a4feafa9e67e2617031be0afe2 and fixed in 7.1 with commit 4f8ef58c10bfe5f86a643c7c8331b37e69e3dae1

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-64519
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	fs/nfsd/nfs4state.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/d1fc00ec02e9deb3f8d2bd59caf938c554fbc576
	https://git.kernel.org/stable/c/fe59ae27d7346245f5d8d97220f374e63efd28b5
	https://git.kernel.org/stable/c/44e5e4eb3a07bf3e1d931dd9f96f3edcfa376605
	https://git.kernel.org/stable/c/4f8ef58c10bfe5f86a643c7c8331b37e69e3dae1