fuse: fix fuse_retrieve

commit 48706d0a91583d08c56e7ef2a7602d99c8d4133f upstream.

Fix two bugs in fuse_retrieve():

 - retrieving more than one page would yield repeated instances of the
   first page

 - if more than FUSE_MAX_PAGES_PER_REQ pages were requested than the
   request page array would overflow

fuse_retrieve() was added in 2.6.36 and these bugs had been there since the
beginning.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 5cb8614508c339fb5e0c18031f3ebf249a4ec6c0..2aaf3eaaf13da03e328ac3523fe16ca09a60c690 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1512,7 +1512,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
        else if (outarg->offset + num > file_size)
                num = file_size - outarg->offset;
 
-       while (num) {
+       while (num && req->num_pages < FUSE_MAX_PAGES_PER_REQ) {
                struct page *page;
                unsigned int this_num;
 
@@ -1526,6 +1526,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
 
                num -= this_num;
                total_len += this_num;
+               index++;
        }
        req->misc.retrieve_in.offset = outarg->offset;
        req->misc.retrieve_in.size = total_len;