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 D175D516150 for ; Thu, 17 Sep 2026 16:21:28 +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=1789662090; cv=none; b=m9SOFhgtSvaCt0ysdKvhMXhRk+VXGDBbu9KgOUUcne56UbdpNXEQCcvLdQYwl39mrrAo1jaOfWJGD8E2FqXUgHpqdkDRwlsoi5NHxouufBxZ88Zn8WuydY2JXk5YPC8XvWUjO6peiWMXK1GnxQGrhlEEDVRR+lWp9VT+AG0bJno= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789662090; c=relaxed/simple; bh=kyg5WtWjMqKLZGzS/eddvd6uaXiRpb9jXsd5hH/1z3w=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=OpXCRTWi9HiLe9J6Xz4M9zns4P+y4ldQ1wW48pnsp4/OtzbXHmeJamkScF2TsD5TIjK/kDH4xzSWBuo7E4PZOWOL9vIoe9r6IIDDXQnO9ERNjwdGKj5knoPMWM9xHlnqgfzrHZyEeKhWlFpNAdDavB778u9J0CX3ztnZBi6ToyQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pHKiPHmX; 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="pHKiPHmX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D59F1F000FF; Thu, 17 Sep 2026 16:21:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789662088; bh=EsMuhgm4IRK1AxfWg3YFhK8zBWXP2LSNmNihXmWszZI=; h=From:To:Cc:Subject:Date:Reply-To; b=pHKiPHmXUu7uxZH5MSZzlPlI+jPnIjdSTZ4GuXqiBlB6DiIvcY2bObP5X7a+z+Da7 EKDCJNuWFUOOOTKBGngM7IH1Vp8op4A/neM53DHAN3AKz0EMqprQHwNFxGOAM2yqQK YlBxnv+3e8xDfs1DOn8lPIJgkeqI0kPqfUtU418Q= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-90236: NFSD: Release the export reference when reaping open stateids Date: Thu, 17 Sep 2026 17:11:06 +0100 Message-ID: <2026091741-CVE-2026-90236-ee83@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=3167; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=YCAD3woD+PUVSfeFVYTPUYQHEy769dyyX8beTRk3qHk=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlrBDqD+PjfS+/IZPt39lDh+sBYqRp9i6L0kw2f7IzbL cMj/r7tiGVhEGRikBVTZPmyjefo/opDil6Gtqdh5rAygQxh4OIUgIkISzHMj0jNky45ln56D+eh ezGX/z5jflsmxjC/WJCx2SAndSpr94aX5j+b76pyPzwDAA== 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: Release the export reference when reaping open stateids nfs4_put_stid() releases the svc_export tracked in nfs4_stid.sc_export, but free_ol_stateid_reaplist() frees open and lock stateids by calling ->sc_free() directly, bypassing that path. An open stateid takes an sc_export reference in nfs4_open() and a lock stateid takes its own in init_lock_stateid(); both reach free_ol_stateid_reaplist() through their normal teardown, the open stateid via release_open_stateid() and the lock stateid via nfsd4_release_lockowner(), each through put_ol_stateid_locked(). The reference is therefore never dropped, pinning the export and blocking unmount for the lifetime of the stateid. Release sc_export in free_ol_stateid_reaplist() the way nfs4_put_stid() does. ->sc_free() runs once per stateid, and a stateid reaches free_ol_stateid_reaplist() or nfs4_put_stid() but never both, so the reference is dropped exactly once. Revoked stateids reach this path with sc_export already cleared by drop_stid_export(), so they are skipped rather than double-freed. nfs4_put_stid() itself read sc_export before acquiring cl_lock. drop_stid_export() clears that field and releases the reference under cl_lock, so a concurrent revocation could drop the export in the window between the read and the final put, releasing the same reference twice. Read sc_export while cl_lock is held so the two paths serialize and the reference is released exactly once. The Linux kernel CVE team has assigned CVE-2026-90236 to this issue. Affected and fixed versions =========================== Issue introduced in 7.2 with commit ba0cde5dc81d214684b8ea0bd87414ba2f48fe02 and fixed in 7.2.6 with commit 7458727fd7cb79d09e5120b6fecc1ad11cdb0946 Issue introduced in 7.2 with commit ba0cde5dc81d214684b8ea0bd87414ba2f48fe02 and fixed in 7.3-rc1 with commit 6480bd703684ed3f760e9e36c4a699033c0806ae 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-2026-90236 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/7458727fd7cb79d09e5120b6fecc1ad11cdb0946 https://git.kernel.org/stable/c/6480bd703684ed3f760e9e36c4a699033c0806ae