orangefs: validate the response in decode_dirents()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
diff --git a/fs/orangefs/dir.c b/fs/orangefs/dir.c
index eb4c3d3..3049cd6 100644
--- a/fs/orangefs/dir.c
+++ b/fs/orangefs/dir.c
@@ -17,13 +17,17 @@
/*
* decode routine needed by kmod to make sense of the shared page for readdirs.
*/
-static long decode_dirents(char *ptr, struct pvfs2_readdir_response_s *readdir)
+static long decode_dirents(char *ptr, size_t size,
+ struct pvfs2_readdir_response_s *readdir)
{
int i;
struct pvfs2_readdir_response_s *rd =
(struct pvfs2_readdir_response_s *) ptr;
char *buf = ptr;
+ if (size < offsetof(struct pvfs2_readdir_response_s, dirent_array))
+ return -EINVAL;
+
readdir->token = rd->token;
readdir->pvfs_dirent_outcount = rd->pvfs_dirent_outcount;
readdir->dirent_array = kcalloc(readdir->pvfs_dirent_outcount,
@@ -31,21 +35,43 @@
GFP_KERNEL);
if (readdir->dirent_array == NULL)
return -ENOMEM;
+
buf += offsetof(struct pvfs2_readdir_response_s, dirent_array);
+ size -= offsetof(struct pvfs2_readdir_response_s, dirent_array);
+
for (i = 0; i < readdir->pvfs_dirent_outcount; i++) {
- __u32 len = *(__u32 *)buf;
+ __u32 len;
+
+ if (size < 4)
+ goto Einval;
+
+ len = *(__u32 *)buf;
+ if (len >= (unsigned)-24)
+ goto Einval;
+
readdir->dirent_array[i].d_name = buf + 4;
- buf += roundup8(4 + len + 1);
readdir->dirent_array[i].d_length = len;
+
+ len = roundup8(4 + len + 1);
+ if (size < len + 16)
+ goto Einval;
+ size -= len + 16;
+
+ buf += len;
+
readdir->dirent_array[i].khandle =
*(struct pvfs2_khandle *) buf;
buf += 16;
}
return buf - ptr;
+Einval:
+ kfree(readdir->dirent_array);
+ readdir->dirent_array = NULL;
+ return -EINVAL;
}
static long readdir_handle_ctor(struct readdir_handle_s *rhandle, void *buf,
- int buffer_index)
+ size_t size, int buffer_index)
{
long ret;
@@ -61,7 +87,7 @@
}
rhandle->buffer_index = buffer_index;
rhandle->dents_buf = buf;
- ret = decode_dirents(buf, &rhandle->readdir_response);
+ ret = decode_dirents(buf, size, &rhandle->readdir_response);
if (ret < 0) {
gossip_err("Could not decode readdir from buffer %ld\n", ret);
rhandle->buffer_index = -1;
@@ -209,6 +235,7 @@
bytes_decoded =
readdir_handle_ctor(&rhandle,
new_op->downcall.trailer_buf,
+ new_op->downcall.trailer_size,
buffer_index);
if (bytes_decoded < 0) {
gossip_err("pvfs2_readdir: Could not decode trailer buffer into a readdir response %d\n",