From: Miklos Szeredi <mszeredi@redhat.com>
Date: Thu, 16 Feb 2017 16:49:02 +0000 (+0100)
Subject: vfs: fix uninitialized flags in splice_to_pipe()
X-Git-Tag: v3.16.42~70
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=36733716d779232ca726aa14cf1482a6d97c2bd5;p=thirdparty%2Fkernel%2Fstable.git

vfs: fix uninitialized flags in splice_to_pipe()

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@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/fs/splice.c b/fs/splice.c
index 962c7f7e03f6c..41f10ce929dde 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -212,6 +212,7 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
 			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;