From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 5.0 052/173] f2fs: fix to do checksum even if inode page is uptodate Date: Sat, 1 Jun 2019 09:17:24 -0400 Message-ID: <20190601131934.25053-52-sashal@kernel.org> References: <20190601131934.25053-1-sashal@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-4.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1hX3x3-0003cE-Qg for linux-f2fs-devel@lists.sourceforge.net; Sat, 01 Jun 2019 13:21:37 +0000 Received: from mail.kernel.org ([198.145.29.99]) by sfi-mx-3.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) id 1hX3x0-00EcHH-Sx for linux-f2fs-devel@lists.sourceforge.net; Sat, 01 Jun 2019 13:21:36 +0000 In-Reply-To: <20190601131934.25053-1-sashal@kernel.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sasha Levin , Jaegeuk Kim , linux-f2fs-devel@lists.sourceforge.net From: Chao Yu [ Upstream commit b42b179bda9ff11075a6fc2bac4d9e400513679a ] As Jungyeon reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203221 - Overview When mounting the attached crafted image and running program, this error is reported. The image is intentionally fuzzed from a normal f2fs image for testing and I enabled option CONFIG_F2FS_CHECK_FS on. - Reproduces cc poc_07.c mkdir test mount -t f2fs tmp.img test cp a.out test cd test sudo ./a.out - Messages kernel BUG at fs/f2fs/node.c:1279! RIP: 0010:read_node_page+0xcf/0xf0 Call Trace: __get_node_page+0x6b/0x2f0 f2fs_iget+0x8f/0xdf0 f2fs_lookup+0x136/0x320 __lookup_slow+0x92/0x140 lookup_slow+0x30/0x50 walk_component+0x1c1/0x350 path_lookupat+0x62/0x200 filename_lookup+0xb3/0x1a0 do_fchmodat+0x3e/0xa0 __x64_sys_chmod+0x12/0x20 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 On below paths, we can have opportunity to readahead inode page - gc_node_segment -> f2fs_ra_node_page - gc_data_segment -> f2fs_ra_node_page - f2fs_fill_dentries -> f2fs_ra_node_page Unlike synchronized read, on readahead path, we can set page uptodate before verifying page's checksum, then read_node_page() will trigger kernel panic once it encounters a uptodated page w/ incorrect checksum. So considering readahead scenario, we have to do checksum each time when loading inode page even if it is uptodated. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/inode.c | 4 ++-- fs/f2fs/node.c | 7 ++++--- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 8c8d40e07ebaf..24c81703ec56f 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -176,8 +176,8 @@ bool f2fs_inode_chksum_verify(struct f2fs_sb_info *sbi, struct page *page) if (provided != calculated) f2fs_msg(sbi->sb, KERN_WARNING, - "checksum invalid, ino = %x, %x vs. %x", - ino_of_node(page), provided, calculated); + "checksum invalid, nid = %lu, ino_of_node = %x, %x vs. %x", + page->index, ino_of_node(page), provided, calculated); return provided == calculated; } diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 63bb6134d39ae..e29d5f6735ae9 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1281,9 +1281,10 @@ static int read_node_page(struct page *page, int op_flags) int err; if (PageUptodate(page)) { -#ifdef CONFIG_F2FS_CHECK_FS - f2fs_bug_on(sbi, !f2fs_inode_chksum_verify(sbi, page)); -#endif + if (!f2fs_inode_chksum_verify(sbi, page)) { + ClearPageUptodate(page); + return -EBADMSG; + } return LOCKED_PAGE; } -- 2.20.1