[39/45] fuse: fix fuse_retrieve

From: Greg KH
Date: Fri Dec 16 2011 - 14:56:07 EST


3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <mszeredi@xxxxxxx>

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@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
fs/fuse/dev.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1512,7 +1512,7 @@ static int fuse_retrieve(struct fuse_con
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_con

num -= this_num;
total_len += this_num;
+ index++;
}
req->misc.retrieve_in.offset = outarg->offset;
req->misc.retrieve_in.size = total_len;


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