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 AA8F2378838; Fri, 4 Sep 2026 06:09:25 +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=1788502166; cv=none; b=cxmOTd6LZToumMn+uMm16Esfp8/5EkufehFJhs1c8kGTbm1GKVqSS+gmzuH3OX5ea3H9oVKXSscPkTnE2BgkmZer8emwbGrs2iggiHWklsAZfzejOQWP5J8/ocVoT9cMVbPzaFgnBlKd+TQ4zOk9izaLj7y7NbhKVhIEq82oGBo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788502166; c=relaxed/simple; bh=8ZWnBtdYQnYihVk1xPd/gEgxhR2Uut6zA7TECMuVs+Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=XDY4vdXXFwGT/zXr5BwnVI4BTNX9G6gHIKs5H6KFCoO0Vo3KwTzMLZ2GqXg6XtZFXAQAJKu+evrYDl3t0N4Qi1shx9dg4lf7UFfh8ThBeOoaki60ILjAq08Le/f7bHMrARE4fiFkNfKR+KcXJMStWt/8lkm8gY5LqRojHrUd0N8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=C2s9YvrR; 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="C2s9YvrR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1079D1F00A3D; Fri, 4 Sep 2026 06:09:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788502165; bh=+D+u86lBGlfaD8w1qq3xSY4dJCRAiJgusE6/DD0XwJI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=C2s9YvrRvIORjEUbf9f/4v7fiKYHR5SG6d8vnuUqPLUB9YPfDVXKXVf/Ti6OTRtUX yEPlcF0xmO4AWfnTG2lT1ukQlMbnxy+LDJDwa2yjjzT2pHa6C1MXnQkOQrLwSQWKR1 d8qcUKmJdV/Lt2EkQ9szG0VIdbaT5LUvmj3+DinE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?J=C3=A9r=C3=A9my=20Jean?= , Alex Markuze , Ilya Dryomov Subject: [PATCH 6.12 112/403] ceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode Date: Fri, 4 Sep 2026 06:58:35 +0200 Message-ID: <20260904045737.376425981@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045734.806166532@linuxfoundation.org> References: <20260904045734.806166532@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jérémy Jean commit aedc9053d909508a5f56c3f49f885fc030df4730 upstream. MDSMap export_targets entries are monitor controlled. check_new_map() uses each entry as a bit number in a fixed stack bitmap, so a rank outside the protocol namespace can make set_bit() write past the end of the array. Reject ranks outside CEPH_MAX_MDS while decoding the map. Do not validate against possible_max_rank here because maps may legitimately reference ranks beyond a temporarily reduced max_mds. Cc: stable@vger.kernel.org Fixes: d517b3983dd3 ("ceph: reconnect to the export targets on new mdsmaps") Signed-off-by: Jérémy Jean Reviewed-by: Alex Markuze Signed-off-by: Alex Markuze Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman --- fs/ceph/mdsmap.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/fs/ceph/mdsmap.c +++ b/fs/ceph/mdsmap.c @@ -264,6 +264,10 @@ struct ceph_mdsmap *ceph_mdsmap_decode(s goto nomem; for (j = 0; j < num_export_targets; j++) { target = ceph_decode_32(&pexport_targets); + if (target >= CEPH_MAX_MDS) { + err = -EIO; + goto corrupt; + } info->export_targets[j] = target; } } else {