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authorDan Rosenberg <dan.j.rosenberg@gmail.com>2010-06-24 12:07:47 +1000
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-10 09:52:55 -0700
commite1377aee4e4d4f5f0621b399b247b0790330b4c9 (patch)
treeedf0bbc4b5c688dbba1e5c22595cb5a7f0daa071 /fs
parentcf32802d7620d7f0e7b1c360cdd5821f2d10a3b0 (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>
Diffstat (limited to 'fs')
-rw-r--r--fs/xfs/xfs_dfrag.c5
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;