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 7CC68381AF9; Fri, 4 Sep 2026 05:45:25 +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=1788500726; cv=none; b=PEh1WTqYL2Ovx/QzQrM9c7SfOBsuTeT4Amr/3Hc4c5h3dZ3UGXEfRcHiLjzuuiyEjEzfd1k6UaF+1tIdBG7eJ5bKzQ45F0RI8qAGyn2a1FSCwLkrE7roo4qHx/l+Tsu2LrJdT/cNg5W3czBei8Oub32g72dN/L2zfET4DSop6y0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788500726; c=relaxed/simple; bh=5VnrDp9gjuoQxuQUXldoGhbOMb3WLPOjPFRH2Zx9jZE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=uF0n/TClCe9VOO6xM+2XrgI+RA6dOtvAIQ0rl9OYMek+v09Q6+6ZI8RhN0A/VtzfKkq8EwWo3FdhbgibFwvPMrn8NB9rupEtriCqVas39/FJhNEDOUUms4pf8c1JXvdl1D1O7amoKcfAw4fvjrA6DtC8zz+DezigiMRVo/DcWzA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EG5S4wM7; 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="EG5S4wM7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6E6C1F00A3D; Fri, 4 Sep 2026 05:45:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788500725; bh=PrqLRtnMhuXzHw8D6yIK87kGfr4fly+m4yvqVo6Ke5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=EG5S4wM7MKPwQ5rFlqKTbnuKKATkPUqsI042h4ethkjJN5mIi6OLU2ad66IPWqqq+ +BbqXQ8WN23m7iM0r5jOuwgyn/5XVpPNo7MWXhmp8Kr+pb0D/pPUUn5WtmbbddINvo R3y9/+n3BCv+nGBj+yyq1kTyO4pPIda/A9HdKVkc= 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 6.18 156/552] ceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode Date: Fri, 4 Sep 2026 06:55:13 +0200 Message-ID: <20260904045752.399005528@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045747.813364717@linuxfoundation.org> References: <20260904045747.813364717@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 6.18-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 {