From: Vasiliy Kulikov Date: Sun, 17 Oct 2010 14:41:28 +0000 Subject: [PATCH 5/8] char: ppdev: fix information leak to userland Message-Id: <1287326489-8071-1-git-send-email-segooon@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kernel-janitors@vger.kernel.org Cc: Andrew Morton , Julia Lawall , Tejun Heo , Arnd Bergmann , linux-kernel@vger.kernel.org Structure par_timeout is copied to userland with some padding fields unitialized. Field tv_usec has type __kernel_suseconds_t, it differs from tv_sec's type on some architectures. It leads to leaking of stack memory. Signed-off-by: Vasiliy Kulikov --- Compile tested. drivers/char/ppdev.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c index 723152d..f176dba 100644 --- a/drivers/char/ppdev.c +++ b/drivers/char/ppdev.c @@ -613,6 +613,7 @@ static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case PPGETTIME: to_jiffies = pp->pdev->timeout; + memset(&par_timeout, 0, sizeof(par_timeout)); par_timeout.tv_sec = to_jiffies / HZ; par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ); if (copy_to_user (argp, &par_timeout, sizeof(struct timeval))) -- 1.7.0.4