hfs: add sanity check for file name length

On a corrupted file system the ->len field could be wrong leading to
a buffer overflow.

Reported-and-acked-by: Clement LECIGNE <clement.lecigne@netasq.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/hfs/trans.c b/fs/hfs/trans.c
index e673a88b8ae7..b1ce4c7ad3fb 100644
--- a/fs/hfs/trans.c
+++ b/fs/hfs/trans.c
@@ -40,6 +40,8 @@ int hfs_mac2asc(struct super_block *sb, char *out, const struct hfs_name *in)
 
         src = in->name;
         srclen = in->len;
+        if (srclen > HFS_NAMELEN)
+                srclen = HFS_NAMELEN;
         dst = out;
         dstlen = HFS_MAX_NAMELEN;
         if (nls_io) {