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 8C19748F84A for ; Fri, 25 Sep 2026 10:24:40 +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=1790331881; cv=none; b=P8+fRc8L3B0zHkZEsnhgPI0fY9fBAoadWXO9qivaorrwrk1kYVBlq+K9FOwJ30SlINzEou/p+TGepiDUZ0PggM5w8wjo/b/HdIuBOXwZZiUeSXnFRlDCbcI2e3fcAR+CulTN1o/3o86UH16PiFWSnXE6dvgLq1o1qi5Xy2emSJg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790331881; c=relaxed/simple; bh=Awdlqu8YgBashG1j3Iwa4/QCiNUR7hNwbhj3n33G6nQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=LtnNob/Fic61M5X0xHdnDVBUrd2SnLWj3Oj/OOlfoOSYKVjnrqVFqY72MIkhK98JdU6vGBzDqW8P5PI4Uq3cYY5izWUWr6CdozqItPQdo3nV/cB0f+T8evxI5rYFBzmOrTjWrSvtRkc9X1Xwhob5OaBMGkdXN0qDloX5/G/PiUE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qlPqZKQc; 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="qlPqZKQc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1EE61F000FF; Fri, 25 Sep 2026 10:24:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790331880; bh=bmMk+2ECs0mBy+7NcCFVqJPNliBeYzRCk66l2GOeroQ=; h=From:To:Cc:Subject:Date:Reply-To; b=qlPqZKQciN2jAiZykCF/8ttBCOwLOg+DLfPMTFO493QlQlPW7Ut/2buoEB9FSFtTg whEh2IODEjho8JD6P7ODUcicPBl5hR+MgA8fGx0tioZfLz9A1HTOSSJ9s2igVco1sZ rvpaJXdIVUIPH827QHuXGzxPm7AvyWfkSs3sLehU= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-97564: smb: client: reject userspace cifs.idmap descriptions Date: Fri, 25 Sep 2026 12:22:24 +0200 Message-ID: <2026092553-CVE-2026-97564-90ef@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=3180; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=uFbeXTzih7BCRUAzLQhIqCPgF0jWIjWipKwJUrDwfQs=; b=owGbwMvMwCRo6H6F97bub03G02pJDFnbvB2dFuWUpU74t/+f6N5M/Uev3opfSLP5p1Pcu1XSv UcmoPJGRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenANzkZIbZLFfuSGXp+yerpU0Q nZ4nv073p9djhgV7VOsa2VU+V96MX+wYNn/9rl2ThLQB 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: smb: client: reject userspace cifs.idmap descriptions cifs.idmap key descriptions carry authority-bearing fields (owner and group SIDs and uid/gid values in "os:"/"gs:"/"oi:"/"gi:" form) that the cifs.idmap upcall helper treats as kernel-originating inputs. Unlike its sibling cifs.spnego, the cifs.idmap key type has no vet_description hook, so userspace can create keys of this type through request_key(2)/add_key(2) and supply those fields without CIFS origin. A request_key(2) call with a non-NULL callout then drives a root usermodehelper upcall (/sbin/request-key -> cifs.idmap) that consumes the unvetted description in root context. Only accept cifs.idmap descriptions while CIFS is using its private root_cred to request the key. id_to_sid()/sid_to_id() already run under override_creds(root_cred), so the kernel-originated path is unaffected. This mirrors commit 3da1fdf4efbc ("smb: client: reject userspace cifs.spnego descriptions"), which applied the same restriction to cifs.spnego. The Linux kernel CVE team has assigned CVE-2026-97564 to this issue. Affected and fixed versions =========================== Issue introduced in 3.0 with commit 4d79dba0e00749fa40de8ef13a9b85ce57a1603b and fixed in 6.12.111 with commit e5964064e3fbe6325893408faff08ca33de0e2c3 Issue introduced in 3.0 with commit 4d79dba0e00749fa40de8ef13a9b85ce57a1603b and fixed in 6.18.53 with commit 96751028c0d4dec785709ea3eb0ab38a4f2ded96 Issue introduced in 3.0 with commit 4d79dba0e00749fa40de8ef13a9b85ce57a1603b and fixed in 7.2.7 with commit 1d3b24b16a0b013792e8f1e3ed060f0b46f537d1 Issue introduced in 3.0 with commit 4d79dba0e00749fa40de8ef13a9b85ce57a1603b and fixed in 7.3-rc3 with commit d9d7eeb0cea5b55b82888f443622fd8d4ee064f3 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-2026-97564 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/smb/client/cifsacl.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/e5964064e3fbe6325893408faff08ca33de0e2c3 https://git.kernel.org/stable/c/96751028c0d4dec785709ea3eb0ab38a4f2ded96 https://git.kernel.org/stable/c/1d3b24b16a0b013792e8f1e3ed060f0b46f537d1 https://git.kernel.org/stable/c/d9d7eeb0cea5b55b82888f443622fd8d4ee064f3