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>
This commit is contained in:
Al Viro 2015-10-09 18:11:10 -04:00 committed by Mike Marshall
parent ade1d48b78
commit 8092895f75

View file

@ -17,13 +17,17 @@ struct readdir_handle_s {
/*
* 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 @@ static long decode_dirents(char *ptr, struct pvfs2_readdir_response_s *readdir)
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 @@ static long readdir_handle_ctor(struct readdir_handle_s *rhandle, void *buf,
}
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 @@ static int pvfs2_readdir(struct file *file, struct dir_context *ctx)
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",