From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3B6AC433E1 for ; Thu, 20 Aug 2020 13:07:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92BE7207BB for ; Thu, 20 Aug 2020 13:07:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597928855; bh=Sc+dJRzIybQxELrEsnAJ8I+605+1r7Gbwe/S4Gebl78=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Z4t3p/6A4vRwH0uo6jDhTACthaR/1aOlBmHaehZ0N7Rm4Sy2ZxEGXTmPc91vehRGk T6AnrhdyaA/Sq1v2e8MZ2zZGZ8deb3v/d7H6S2mI7ZVF15RdpTA2XY1iGEFIUf2jLq LvWtXNHwLHfuEpxB4ls1HJ9aURzuHoXLdWKblkrE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729751AbgHTNHS (ORCPT ); Thu, 20 Aug 2020 09:07:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:56306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728839AbgHTJib (ORCPT ); Thu, 20 Aug 2020 05:38:31 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A802C2173E; Thu, 20 Aug 2020 09:38:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597916311; bh=Sc+dJRzIybQxELrEsnAJ8I+605+1r7Gbwe/S4Gebl78=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wLkAvAWCaGRDEOaJT76Jprt58k/sYzCqm4p1uJiafGITqRW3ZTpHTTCaDIxrNYO03 XsA8TDyEICD9Il1l/24KVFs+PjLcPMIhpz+Wagi0x3ROp0m8yl7r9Or4cgf4qpLbtc Fwh2rgFnuR6ko7OIOuAvYkQOxfulsXekUDaX9C3Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeff Layton , Ilya Dryomov , Patrick Donnelly Subject: [PATCH 5.7 084/204] ceph: handle zero-length feature mask in session messages Date: Thu, 20 Aug 2020 11:19:41 +0200 Message-Id: <20200820091610.538859326@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091606.194320503@linuxfoundation.org> References: <20200820091606.194320503@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jeff Layton commit 02e37571f9e79022498fd0525c073b07e9d9ac69 upstream. Most session messages contain a feature mask, but the MDS will routinely send a REJECT message with one that is zero-length. Commit 0fa8263367db ("ceph: fix endianness bug when handling MDS session feature bits") fixed the decoding of the feature mask, but failed to account for the MDS sending a zero-length feature mask. This causes REJECT message decoding to fail. Skip trying to decode a feature mask if the word count is zero. Cc: stable@vger.kernel.org URL: https://tracker.ceph.com/issues/46823 Fixes: 0fa8263367db ("ceph: fix endianness bug when handling MDS session feature bits") Signed-off-by: Jeff Layton Reviewed-by: Ilya Dryomov Tested-by: Patrick Donnelly Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman --- fs/ceph/mds_client.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -3270,8 +3270,10 @@ static void handle_session(struct ceph_m goto bad; /* version >= 3, feature bits */ ceph_decode_32_safe(&p, end, len, bad); - ceph_decode_64_safe(&p, end, features, bad); - p += len - sizeof(features); + if (len) { + ceph_decode_64_safe(&p, end, features, bad); + p += len - sizeof(features); + } } mutex_lock(&mdsc->mutex);