diff options
| author | Amerigo Wang <amwang@redhat.com> | 2009-12-15 04:57:37 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-15 19:53:10 +0300 |
| commit | ec81aecb29668ad71f699f4e7b96ec46691895b6 (patch) | |
| tree | 0a66a8fb41689955e3400cba7fc7419f4183dec5 /fs/hfs/super.c | |
| parent | 4b731d50ff3df6b9141a6c12b088e8eb0109e83c (diff) | |
| download | linux-ec81aecb29668ad71f699f4e7b96ec46691895b6.tar.xz | |
hfs: fix a potential buffer overflow
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 <amwang@redhat.com>
Cc: Eugene Teo <eteo@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Dave Anderson <anderson@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/hfs/super.c')
| -rw-r--r-- | fs/hfs/super.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/hfs/super.c b/fs/hfs/super.c index f7fcbe49da72..5ed7252b7b23 100644 --- a/fs/hfs/super.c +++ b/fs/hfs/super.c @@ -409,8 +409,13 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent) /* 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; |