diff options
| author | Dan Rosenberg <dan.j.rosenberg@gmail.com> | 2010-06-24 12:07:47 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-10 09:52:55 -0700 |
| commit | e1377aee4e4d4f5f0621b399b247b0790330b4c9 (patch) | |
| tree | edf0bbc4b5c688dbba1e5c22595cb5a7f0daa071 | |
| parent | cf32802d7620d7f0e7b1c360cdd5821f2d10a3b0 (diff) | |
xfs: prevent swapext from operating on write-only files
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>
| -rw-r--r-- | fs/xfs/xfs_dfrag.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/xfs/xfs_dfrag.c b/fs/xfs/xfs_dfrag.c index 75b0cd4da0ea..ce2a6a21995c 100644 --- 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; |