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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 5D41CC433DB for ; Fri, 29 Jan 2021 18:09:04 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3E73D64E09 for ; Fri, 29 Jan 2021 18:09:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E73D64E09 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=mail.scut.edu.cn Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4DS5253ZZ9zDsTK for ; Sat, 30 Jan 2021 05:09:01 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=mail.scut.edu.cn (client-ip=202.38.213.20; helo=mail.scut.edu.cn; envelope-from=sehuww@mail.scut.edu.cn; receiver=) Received: from mail.scut.edu.cn (stumail1.scut.edu.cn [202.38.213.20]) by lists.ozlabs.org (Postfix) with ESMTP id 4DS51v5FgYzDsDx for ; Sat, 30 Jan 2021 05:08:42 +1100 (AEDT) Received: from localhost.localdomain (unknown [10.1.129.4]) by front (Coremail) with SMTP id AWSowAB3fOACTxRg6ZwhAg--.22951S4; Sat, 30 Jan 2021 02:08:03 +0800 (CST) From: Hu Weiwen To: hsiangkao@redhat.com Subject: [PATCH v2] erofs-utils: fuse: fix random readlink error Date: Sat, 30 Jan 2021 02:07:47 +0800 Message-Id: <20210129180747.67731-1-sehuww@mail.scut.edu.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210123152213.GB3167351@xiangao.remote.csb> References: <20210123152213.GB3167351@xiangao.remote.csb> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: AWSowAB3fOACTxRg6ZwhAg--.22951S4 X-Coremail-Antispam: 1UD129KBjvJXoW7Zr4DWrWxCr1fKF4furWkCrg_yoW8ZFW5pr Wq9rZ5GF1ftry7Wr4ft3Z8Z3WYq3WkKF1UC3yrCw4fA3srJFn8Z3WrAF909w43Cr1kAF4Y qanI9wn5urW7JrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUyG14x267AKxVWUJVW8JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r1j6r1xM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r1j 6r4UM28EF7xvwVC2z280aVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVCY1x0267AKxVWxJr 0_GcWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1l42xK82IYc2Ij64vI r41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8Gjc xK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1Y6r17MIIYrxkI7VAKI48JMIIF0xvE2Ix0 cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE42xK8V AvwI8IcIk0rVWrZr1j6s0DMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7Cj xVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7VUbrMaUUUUUU== X-CM-SenderInfo: qsqrljqqwxllyrt6zt1loo2ulxwovvfxof0/1tbiAQAJBlepTBDjTwAWsW X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-erofs@lists.ozlabs.org Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" readlink should fill a **null-terminated** string in the buffer. To achieve this: 1) memset(0) for unmapped extents; 2) make erofsfuse_read() properly returning the actual bytes read; 3) insert a null character if the path is truncated. Link: https://lore.kernel.org/r/20210121101233.GC6680@DESKTOP-N4CECTO.huww98.cn Signed-off-by: Hu Weiwen --- fuse/main.c | 8 ++++++++ lib/data.c | 6 ++++++ 2 files changed, 14 insertions(+) diff --git a/fuse/main.c b/fuse/main.c index c162912..70558b0 100644 --- a/fuse/main.c +++ b/fuse/main.c @@ -74,6 +74,10 @@ static int erofsfuse_read(const char *path, char *buffer, ret = erofs_pread(&vi, buffer, size, offset); if (ret) return ret; + if (offset + size > vi.i_size) + return vi.i_size - offset; + if (offset >= vi.i_size) + return 0; return size; } @@ -83,6 +87,10 @@ static int erofsfuse_readlink(const char *path, char *buffer, size_t size) if (ret < 0) return ret; + DBG_BUGON(ret > size); + if (ret == size) + buffer[size - 1] = '\0'; + erofs_dbg("readlink result %s", buffer); return 0; } diff --git a/lib/data.c b/lib/data.c index 3781846..3641536 100644 --- a/lib/data.c +++ b/lib/data.c @@ -29,6 +29,7 @@ static int erofs_map_blocks_flatmode(struct erofs_inode *inode, if (offset >= inode->i_size) { /* leave out-of-bound access unmapped */ map->m_flags = 0; + map->m_plen = 0; goto out; } @@ -91,9 +92,13 @@ static int erofs_read_raw_data(struct erofs_inode *inode, char *buffer, if (!(map.m_flags & EROFS_MAP_MAPPED)) { if (!map.m_llen) { + /* reached EOF */ + memset(buffer + ptr - offset, 0, + offset + size - ptr); ptr = offset + size; continue; } + memset(buffer + map.m_la - offset, 0, map.m_llen); ptr = map.m_la + map.m_llen; continue; } @@ -138,6 +143,7 @@ static int z_erofs_read_data(struct erofs_inode *inode, char *buffer, return ret; if (!(map.m_flags & EROFS_MAP_MAPPED)) { + memset(buffer + map.m_la - offset, 0, map.m_llen); end = map.m_la; continue; } -- 2.25.1