| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.12 61/83] xfs: add capability check to free eofblocks ioctl | Date | Fri, 6 Dec 2013 13:51:51 -0800 |
| |
3.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dwight Engen <dwight.engen@oracle.com>
commit 8c567a7fab6e086a0284eee2db82348521e7120c upstream.
Check for CAP_SYS_ADMIN since the caller can truncate preallocated blocks from files they do not own nor have write access to. A more fine grained access check was considered: require the caller to specify their own uid/gid and to use inode_permission to check for write, but this would not catch the case of an inode not reachable via path traversal from the callers mount namespace.
Add check for read-only filesystem to free eofblocks ioctl.
Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: Dwight Engen <dwight.engen@oracle.com> Signed-off-by: Ben Myers <bpm@sgi.com> Cc: Kees Cook <keescook@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/xfs/xfs_ioctl.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -1717,6 +1717,12 @@ xfs_file_ioctl( if (mp->m_flags & XFS_MOUNT_RDONLY) return -XFS_ERROR(EROFS); + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (mp->m_flags & XFS_MOUNT_RDONLY) + return -XFS_ERROR(EROFS); + if (copy_from_user(&eofb, arg, sizeof(eofb))) return -XFS_ERROR(EFAULT);
|