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 10:20:44 -0700 |
| commit | 7a4c13ac72f77cbbaa780c7a53e6bb8d586ff2d9 (patch) | |
| tree | cf874996be1cb3224c5b35fe83b15d9790098c79 | |
| parent | 001632030b5d98ac56c65416a884a90a33a40097 (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 73c22278fdaf..e4ccd9f24829 100644 --- a/fs/xfs/xfs_dfrag.c +++ b/fs/xfs/xfs_dfrag.c @@ -62,7 +62,9 @@ xfs_swapext( goto out; } - 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; } @@ -74,6 +76,7 @@ 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; |