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| 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 /fs/hfs/dir.c | |
| parent | 4b731d50ff3df6b9141a6c12b088e8eb0109e83c (diff) | |
| download | kernel-common-ec81aecb29668ad71f699f4e7b96ec46691895b6.tar.gz kernel-common-ec81aecb29668ad71f699f4e7b96ec46691895b6.tar.bz2 kernel-common-ec81aecb29668ad71f699f4e7b96ec46691895b6.zip | |
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/dir.c')
| -rw-r--r-- | fs/hfs/dir.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c index 7c69b98a2e45..2b3b8611b41b 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); |