From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Brian Foster , Dave Chinner , Gao feng , Dwight Engen , Ben Myers , Kees Cook Subject: [PATCH 3.10 42/58] xfs: add capability check to free eofblocks ioctl Date: Fri, 6 Dec 2013 13:52:13 -0800 Message-Id: <20131206214848.794009398@linuxfoundation.org> In-Reply-To: <20131206214844.906193530@linuxfoundation.org> References: <20131206214844.906193530@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dwight Engen 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 Reviewed-by: Dave Chinner Reviewed-by: Gao feng Signed-off-by: Dwight Engen Signed-off-by: Ben Myers Cc: Kees Cook Signed-off-by: Greg Kroah-Hartman --- fs/xfs/xfs_ioctl.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -1612,6 +1612,12 @@ xfs_file_ioctl( case XFS_IOC_FREE_EOFBLOCKS: { struct xfs_eofblocks eofb; + 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);