diff options
| author | Amerigo Wang <amwang@redhat.com> | 2009-12-14 17:57:37 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-15 08:53:10 -0800 |
| commit | ec81aecb29668ad71f699f4e7b96ec46691895b6 (patch) | |
| tree | 0a66a8fb41689955e3400cba7fc7419f4183dec5 | |
| parent | 4b731d50ff3df6b9141a6c12b088e8eb0109e83c (diff) | |
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>
| -rw-r--r-- | fs/hfs/catalog.c | 4 | ||||
| -rw-r--r-- | fs/hfs/dir.c | 11 | ||||
| -rw-r--r-- | fs/hfs/super.c | 7 |
3 files changed, 21 insertions, 1 deletions
diff --git a/fs/hfs/catalog.c b/fs/hfs/catalog.c index 6d98f116ca0..424b0337f52 100644 --- a/fs/hfs/catalog.c +++ b/fs/hfs/catalog.c @@ -289,6 +289,10 @@ int hfs_cat_move(u32 cnid, struct inode *src_dir, struct qstr *src_name, 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); diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c index 7c69b98a2e4..2b3b8611b41 100644 --- a/fs/hfs/dir.c +++ b/fs/hfs/dir.c @@ -79,6 +79,11 @@ static int hfs_readdir(struct file *filp, void *dirent, filldir_t filldir) 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, void *dirent, filldir_t filldir) 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); diff --git a/fs/hfs/super.c b/fs/hfs/super.c index f7fcbe49da7..5ed7252b7b2 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; |