From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 02F3C58B6D5 for ; Fri, 11 Sep 2026 20:01:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156880; cv=none; b=DEMOQ3Wcpqdubu6HYf1s0QWki+6ZUGdoRZERMaPhEvx+lqzH36JgdAQQfG0DtmKcNqn/glFB7pgtb6MWLedTXZp305Y7KCBAeAaJtp6kfHuVdjNuWOrkezovbym5kGLRKzkcf6xGxV+aq3SD32tkI9Gg98X2ZlTMVKx9nhWkAbY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156880; c=relaxed/simple; bh=+wylg0qbGi2NOR6Jc2VJU0jGKR+ki/mcXOFtkQQxX7k=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=rIFa6WwcYv3esfPNeAfdRgsZfRWwoEmi1zqZ2K8G5PR9kIUH5th7aDnpXvL3BS+uwYLBMqYVciVk/Fm2VudC4m3ozk6Gf/dQhChxyLUAFvRDixknSW3b/SqAdEjBChm5/rCnW3EBAK/9KCnBsJhBSorhSTsl9r6eOVT1Nhpx1ng= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PboqBby8; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="PboqBby8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29E4F1F0089A; Fri, 11 Sep 2026 20:01:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156868; bh=lswtChMuUaBxruCbWIw0Ml4Ryv4Ejj5y14ucSSZtVsw=; h=From:To:Cc:Subject:Date:Reply-To; b=PboqBby8ftin7Ncle0xGDoDMhVrfOvkN5eiuiFfmAOrbtR1ECArfkrTVLmbbwggcX znzoSdwEsBAv9XHLz87Xhdr7jfQX8FKHZhqQDavfhpQpWSc0qx3iaDbcmPhZzgCb/6 ZK5L0tYjRxyXiOHIad5qPoczajLYSxZHWWd4w8fA= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89658: NFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup Date: Fri, 11 Sep 2026 21:45:47 +0200 Message-ID: <2026091145-CVE-2026-89658-bc53@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2899; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=zeYAp7S8za4rBQwpz9N3gw2E6RlHejpkxP/mmCndhV8=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIqv4aidOrnIuXXQn3u3n3sXOn8zUbrz/rbP6gEli8 L1/cwW7O2JZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAi2dYMCyYGvbu52orte+Sd 6x7cajo+Qm4WBxkWrH33LOL//zPnikIUz0+a8N9PMvHBXAA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: NFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup nfs40_clean_admin_revoked() takes a stateid reference under clp->cl_lock, drops nn->client_lock, and calls nfsd4_drop_revoked_stid(), which dereferences the stateid's client through s->sc_client->cl_lock. The stateid reference does not pin the client, so a teardown racing the dropped lock can free the client while nfsd4_drop_revoked_stid() is still using it. This cleanup runs from the laundromat, so a periodic sweep can race force_expire_client() driven by a write to the clients//ctl file. Skip a client that is already expiring and otherwise pin it with cl_rpc_users under client_lock before dropping the lock, matching nfsd4_revoke_states(). The Linux kernel CVE team has assigned CVE-2026-89658 to this issue. Affected and fixed versions =========================== Issue introduced in 6.9 with commit d688d8585e6bea5e4e37f7497feea93b6b0a469c and fixed in 6.12.109 with commit 0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519 Issue introduced in 6.9 with commit d688d8585e6bea5e4e37f7497feea93b6b0a469c and fixed in 6.18.50 with commit b413ec5b23e3445dc9c4f273116078e2d4747626 Issue introduced in 6.9 with commit d688d8585e6bea5e4e37f7497feea93b6b0a469c and fixed in 7.2.4 with commit 81cf7f1413862f87b078920c838460a6a88aa030 Issue introduced in 6.9 with commit d688d8585e6bea5e4e37f7497feea93b6b0a469c and fixed in 7.3-rc1 with commit 7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55 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-2026-89658 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/0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519 https://git.kernel.org/stable/c/b413ec5b23e3445dc9c4f273116078e2d4747626 https://git.kernel.org/stable/c/81cf7f1413862f87b078920c838460a6a88aa030 https://git.kernel.org/stable/c/7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55