[PATCH] overlayfs: Pass O_LARGEFILE unconditionally in ovl_copy_up_data()

[PATCH] overlayfs: Pass O_LARGEFILE unconditionally in ovl_copy_up_data()

[David Howells]

Pass O_LARGEFILE unconditionally in ovl_copy_up_data() as it's purely for
catching 32-bit userspace dealing with a file large enough that it'll be
mishandled if the application isn't aware that there might be an integer
overflow.  Inside the kernel, there shouldn't be any problems.

Reported-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/overlayfs/copy_up.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index d3a5990fd2b9..871fcb67be97 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -76,19 +76,16 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
 	struct file *new_file;
 	loff_t old_pos = 0;
 	loff_t new_pos = 0;
-	int error = 0, o_flag = 0;
+	int error = 0;
 
 	if (len == 0)
 		return 0;
 
-	if (i_size_read(d_inode(old->dentry)) > MAX_NON_LFS)
-		o_flag |= O_LARGEFILE;
-	
-	old_file = ovl_path_open(old, o_flag | O_RDONLY);
+	old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY);
 	if (IS_ERR(old_file))
 		return PTR_ERR(old_file);
 
-	new_file = ovl_path_open(new, o_flag | O_WRONLY);
+	new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY);
 	if (IS_ERR(new_file)) {
 		error = PTR_ERR(new_file);
 		goto out_fput;

Re: [PATCH] overlayfs: Pass O_LARGEFILE unconditionally in ovl_copy_up_data()

[Miklos Szeredi]

On Mon, Sep 28, 2015 at 4:18 PM, David Howells <dhowells@redhat.com> wrote:
> Pass O_LARGEFILE unconditionally in ovl_copy_up_data() as it's purely for
> catching 32-bit userspace dealing with a file large enough that it'll be
> mishandled if the application isn't aware that there might be an integer
> overflow.  Inside the kernel, there shouldn't be any problems.

Folded into original patch with changelog added.

Thanks,
Miklos