From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiang Lu Subject: serial_core:recognize invalid pointer from userspace Date: Wed, 9 Mar 2016 16:02:28 +0800 Message-ID: <1457510549-24801-1-git-send-email-lu.jiang@windriver.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Sender: linux-kernel-owner@vger.kernel.org To: warrick.jiang@gmail.com, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org List-Id: linux-serial@vger.kernel.org Hi, When running setserial, application issue a TIOCGSERIAL iotcl to get serial setting, then update serial setting with TIOCSSERIAL ioctl. It always failed with TIOCSSERIAL ioctl, for application pass 0xffffffff for iomem_base in serial_struct to kernel. On 32bit rootfs & 64bit kernel, compat_ioctl use 0xffffffff as a magic number to mark invalid pointer for iomem_base in serial_struct when truncating a 64bit pointer into 32bit. Serial driver need recognize this invalid pointer when parsing serial_struct from userspace. Thanks Jiang Lu