--- /dev/null
+From 1817176a86352f65210139d4c794ad2d19fc6b63 Mon Sep 17 00:00:00 2001
+From: Dan Rosenberg <dan.j.rosenberg@gmail.com>
+Date: Thu, 24 Jun 2010 12:07:47 +1000
+Subject: xfs: prevent swapext from operating on write-only files
+
+From: Dan Rosenberg <dan.j.rosenberg@gmail.com>
+
+commit 1817176a86352f65210139d4c794ad2d19fc6b63 upstream.
+
+This patch prevents user "foo" from using the SWAPEXT ioctl to swap
+a write-only file owned by user "bar" into a file owned by "foo" and
+subsequently reading it. It does so by checking that the file
+descriptors passed to the ioctl are also opened for reading.
+
+Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
+Reviewed-by: Christoph Hellwig <hch@lst.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
+
+---
+ fs/xfs/xfs_dfrag.c | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+--- a/fs/xfs/xfs_dfrag.c
++++ b/fs/xfs/xfs_dfrag.c
+@@ -74,7 +74,9 @@ xfs_swapext(
+ goto out_free_sxp;
+ }
+
+- if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND)) {
++ if (!(file->f_mode & FMODE_WRITE) ||
++ !(file->f_mode & FMODE_READ) ||
++ (file->f_flags & O_APPEND)) {
+ error = XFS_ERROR(EBADF);
+ goto out_put_file;
+ }
+@@ -86,6 +88,7 @@ xfs_swapext(
+ }
+
+ if (!(target_file->f_mode & FMODE_WRITE) ||
++ !(target_file->f_mode & FMODE_READ) ||
+ (target_file->f_flags & O_APPEND)) {
+ error = XFS_ERROR(EBADF);
+ goto out_put_target_file;