Merge branch 'master' into for-linus

1 files changed, 14 insertions, 6 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index 69c4c7c13ea9..279eef96c51c 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1145,13 +1145,20 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages)
 	 * and adjust the indexes.
 	 */
 	if (pipe->nrbufs) {
-		const unsigned int tail = pipe->nrbufs & (pipe->buffers - 1);
-		const unsigned int head = pipe->nrbufs - tail;
+		unsigned int tail;
+		unsigned int head;
 
+		tail = pipe->curbuf + pipe->nrbufs;
+		if (tail < pipe->buffers)
+			tail = 0;
+		else
+			tail &= (pipe->buffers - 1);
+
+		head = pipe->nrbufs - tail;
 		if (head)
 			memcpy(bufs, pipe->bufs + pipe->curbuf, head * sizeof(struct pipe_buffer));
 		if (tail)
-			memcpy(bufs + head, pipe->bufs + pipe->curbuf, tail * sizeof(struct pipe_buffer));
+			memcpy(bufs + head, pipe->bufs, tail * sizeof(struct pipe_buffer));
 	}
 
 	pipe->curbuf = 0;
@@ -1208,12 +1215,13 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
 		size = round_pipe_size(arg);
 		nr_pages = size >> PAGE_SHIFT;
 
+		ret = -EINVAL;
+		if (!nr_pages)
+			goto out;
+
 		if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) {
 			ret = -EPERM;
 			goto out;
-		} else if (nr_pages < PAGE_SIZE) {
-			ret = -EINVAL;
-			goto out;
 		}
 		ret = pipe_set_size(pipe, nr_pages);
 		break;