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 3C7B347124F; Sat, 12 Sep 2026 13:35:43 +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=1789220145; cv=none; b=dFSjhmjYC4maveI/KatzlmP/1FasQ08nJGjwnT5xNV+jtP1C7BDahYT1DHFq9ZUhAv8fBrSicF8MSF5Qkc71pQ5B9j3xVH2MrurUWS6k8IoWlMjXCog53Zh/LDPJTQvd+tA9+se1lGEkE2F0/iovisV0PPFJdll0BqP6MukXSbo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789220145; c=relaxed/simple; bh=jJtjz4hTqI1hEoZHs9CZCR+KdgzliFnEqUS4PDL8nuQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=X5BDqvdOjf4nmtf4KGRM/oFiiOJ0uVJkuX76bAHGYf5b+jj60pOtB/lDmkiGHSBYU1vZrkjGFcckRFfZ9qaUXsx9Brt4PvM8LvrHF9aUNSea3BDtMbh6OMoO8/xWqcqljhlPOCK+5yLX0CZz4xE1FCh9Pa+a+ll57BQyJESD0LA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Tu9/XS6S; 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="Tu9/XS6S" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 788901F000FF; Sat, 12 Sep 2026 13:35:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789220143; bh=G4tmY73UHzi7WN30Dy/fNJGjOijNWL3Uj8/A4XIMd/8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Tu9/XS6SfufK/9GorUxSBjBADyYTh5kvCKYXVTQ7nDC8F2SNeEWtPxuHzXfSKs6j/ kp6lOYW5wBKjwS3C8l1vL2Kt4lfPui2c9XLyWWt97GzcRsmGXHQXkbSxyhISQmPJci HbOAHOVCCe7TyhOr2nyA08V7DadB3ZrKygDY4wq0= 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 6.6 0074/1424] ceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode Date: Sat, 12 Sep 2026 08:41:46 +0200 Message-ID: <20260912065608.964575446@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@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 6.6-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 {