From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 08D90BA4F for ; Tue, 7 Mar 2023 19:06:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73869C433D2; Tue, 7 Mar 2023 19:06:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678216008; bh=wxjw4NR8IU54R1f6Hmt1oAWT0MFGv0TCe/a7pqST/ak=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WqLrLFYBI3jGq0V1ISklJ6lZ/sm9GG0ZR5j4BKkmTrzm+l3U1NL2EwOraFxCLNamZ b65dxqCzcq03Gj0J0AoZhdj+9xITEwv0fuVDF/BsHtI9CUYSschwoysld1Z5hDXErh atJpqdCZ6L/mPHjYL3pW3G41w2l6Bmea7ghXYJI4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuezhang Mo , Andy Wu , Aoyama Wataru , Sungjong Seo , Namjae Jeon Subject: [PATCH 5.15 446/567] exfat: fix reporting fs error when reading dir beyond EOF Date: Tue, 7 Mar 2023 18:03:02 +0100 Message-Id: <20230307165925.245957799@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307165905.838066027@linuxfoundation.org> References: <20230307165905.838066027@linuxfoundation.org> User-Agent: quilt/0.67 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 From: Yuezhang Mo commit 706fdcac002316893434d753be8cfb549fe1d40d upstream. Since seekdir() does not check whether the position is valid, the position may exceed the size of the directory. We found that for a directory with discontinuous clusters, if the position exceeds the size of the directory and the excess size is greater than or equal to the cluster size, exfat_readdir() will return -EIO, causing a file system error and making the file system unavailable. Reproduce this bug by: seekdir(dir, dir_size + cluster_size); dirent = readdir(dir); The following log will be printed if mount with 'errors=remount-ro'. [11166.712896] exFAT-fs (sdb1): error, invalid access to FAT (entry 0xffffffff) [11166.712905] exFAT-fs (sdb1): Filesystem has been set read-only Fixes: 1e5654de0f51 ("exfat: handle wrong stream entry size in exfat_readdir()") Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Yuezhang Mo Reviewed-by: Andy Wu Reviewed-by: Aoyama Wataru Reviewed-by: Sungjong Seo Signed-off-by: Namjae Jeon Signed-off-by: Greg Kroah-Hartman --- fs/exfat/dir.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/exfat/dir.c +++ b/fs/exfat/dir.c @@ -103,7 +103,7 @@ static int exfat_readdir(struct inode *i clu.dir = ei->hint_bmap.clu; } - while (clu_offset > 0) { + while (clu_offset > 0 && clu.dir != EXFAT_EOF_CLUSTER) { if (exfat_get_next_cluster(sb, &(clu.dir))) return -EIO;