pipe: fix check in "set size" fcntl

As it stands this check compares the number of pages to the page size.
This makes no sense and makes the fcntl fail in almost any sane case.

Fix it by checking if nr_pages is not zero (it can become zero only if
arg is too big and round_pipe_size() overflows).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/fs/pipe.c b/fs/pipe.c
index f31e2d472984182d8d06ebadc4e66c8dd423b735..279eef96c51cdf28a81d4f0c3d0d702a71dc5a1c 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1215,12 +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;