[PATCH 3.2 151/199] vfs: fix uninitialized flags in splice_to_pipe()

From: Ben Hutchings
Date: Fri Mar 10 2017 - 07:06:55 EST

3.2.87-rc1 review patch. If anyone has any objections, please let me know.


From: Miklos Szeredi <mszeredi@xxxxxxxxxx>

commit 5a81e6a171cdbd1fa8bc1fdd80c23d3d71816fac upstream.

Flags (PIPE_BUF_FLAG_PACKET, PIPE_BUF_FLAG_GIFT) could remain on the
unused part of the pipe ring buffer. Previously splice_to_pipe() left
the flags value alone, which could result in incorrect behavior.

Uninitialized flags appears to have been there from the introduction of
the splice syscall.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
fs/splice.c | 1 +
1 file changed, 1 insertion(+)

--- a/fs/splice.c
+++ b/fs/splice.c
@@ -214,6 +214,7 @@ ssize_t splice_to_pipe(struct pipe_inode
buf->len = spd->partial[page_nr].len;
buf->private = spd->partial[page_nr].private;
buf->ops = spd->ops;
+ buf->flags = 0;
if (spd->flags & SPLICE_F_GIFT)
buf->flags |= PIPE_BUF_FLAG_GIFT;