Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763334AbZLQA62 (ORCPT ); Wed, 16 Dec 2009 19:58:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761478AbZLQA6R (ORCPT ); Wed, 16 Dec 2009 19:58:17 -0500 Received: from kroah.org ([198.145.64.141]:44485 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758187AbZLQAyg (ORCPT ); Wed, 16 Dec 2009 19:54:36 -0500 X-Mailbox-Line: From gregkh@mini.kroah.org Wed Dec 16 16:47:07 2009 Message-Id: <20091217004707.607176768@mini.kroah.org> User-Agent: quilt/0.48-1 Date: Wed, 16 Dec 2009 16:45:56 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, WANG Cong , Eugene Teo , Roman Zippel , Al Viro , Christoph Hellwig , Alexey Dobriyan , Dave Anderson Subject: [05/18] hfs: fix a potential buffer overflow In-Reply-To: <20091217005306.GA6230@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3394 Lines: 100 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Amerigo Wang commit ec81aecb29668ad71f699f4e7b96ec46691895b6 upstream. A specially-crafted Hierarchical File System (HFS) filesystem could cause a buffer overflow to occur in a process's kernel stack during a memcpy() call within the hfs_bnode_read() function (at fs/hfs/bnode.c:24). The attacker can provide the source buffer and length, and the destination buffer is a local variable of a fixed length. This local variable (passed as "&entry" from fs/hfs/dir.c:112 and allocated on line 60) is stored in the stack frame of hfs_bnode_read()'s caller, which is hfs_readdir(). Because the hfs_readdir() function executes upon any attempt to read a directory on the filesystem, it gets called whenever a user attempts to inspect any filesystem contents. [amwang@redhat.com: modify this patch and fix coding style problems] Signed-off-by: WANG Cong Cc: Eugene Teo Cc: Roman Zippel Cc: Al Viro Cc: Christoph Hellwig Cc: Alexey Dobriyan Cc: Dave Anderson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/hfs/catalog.c | 4 ++++ fs/hfs/dir.c | 11 +++++++++++ fs/hfs/super.c | 7 ++++++- 3 files changed, 21 insertions(+), 1 deletion(-) --- a/fs/hfs/catalog.c +++ b/fs/hfs/catalog.c @@ -289,6 +289,10 @@ int hfs_cat_move(u32 cnid, struct inode err = hfs_brec_find(&src_fd); if (err) goto out; + if (src_fd.entrylength > sizeof(entry) || src_fd.entrylength < 0) { + err = -EIO; + goto out; + } hfs_bnode_read(src_fd.bnode, &entry, src_fd.entryoffset, src_fd.entrylength); --- a/fs/hfs/dir.c +++ b/fs/hfs/dir.c @@ -79,6 +79,11 @@ static int hfs_readdir(struct file *filp filp->f_pos++; /* fall through */ case 1: + if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) { + err = -EIO; + goto out; + } + hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength); if (entry.type != HFS_CDR_THD) { printk(KERN_ERR "hfs: bad catalog folder thread\n"); @@ -109,6 +114,12 @@ static int hfs_readdir(struct file *filp err = -EIO; goto out; } + + if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) { + err = -EIO; + goto out; + } + hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength); type = entry.type; len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName); --- a/fs/hfs/super.c +++ b/fs/hfs/super.c @@ -386,8 +386,13 @@ static int hfs_fill_super(struct super_b /* try to get the root inode */ hfs_find_init(HFS_SB(sb)->cat_tree, &fd); res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd); - if (!res) + if (!res) { + if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) { + res = -EIO; + goto bail; + } hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength); + } if (res) { hfs_find_exit(&fd); goto bail_no_root; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/