vfs: fix uninitialized flags in splice_to_pipe()

[ Upstream commit 5a81e6a171cdbd1fa8bc1fdd80c23d3d71816fac ]

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>
Cc: <stable@vger.kernel.org> # 2.6.17+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

diff --git a/fs/splice.c b/fs/splice.c
index e7522c48606812a36be7a701465a796a2b710a6a..6ec6054df138b0bd3804882ea40751d74673cbc1 100644 (file)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -211,6 +211,7 @@ 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;