From 8c567a7fab6e086a0284eee2db82348521e7120c Mon Sep 17 00:00:00 2001 From: Dwight Engen Date: Thu, 15 Aug 2013 14:08:03 -0400 Subject: [PATCH] xfs: add capability check to free eofblocks ioctl 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 Reviewed-by: Dave Chinner Reviewed-by: Gao feng Signed-off-by: Dwight Engen Signed-off-by: Ben Myers --- fs/xfs/xfs_ioctl.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index 20b4c7a..bdebc21 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -1723,6 +1723,12 @@ xfs_file_ioctl( struct xfs_fs_eofblocks eofb; struct xfs_eofblocks keofb; + 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); -- 2.7.4