From a0846f1868b11cd827bdfeaf4527d8b1b1c0b098 Mon Sep 17 00:00:00 2001 From: Dan Rosenberg Date: Wed, 15 Sep 2010 17:44:16 -0400 Subject: [PATCH] USB: serial/mos*: prevent reading uninitialized stack memory The TIOCGICOUNT device ioctl in both mos7720.c and mos7840.c allows unprivileged users to read uninitialized stack memory, because the "reserved" member of the serial_icounter_struct struct declared on the stack is not altered or zeroed before being copied back to the user. This patch takes care of it. Signed-off-by: Dan Rosenberg Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/mos7720.c | 3 +++ drivers/usb/serial/mos7840.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c index 30922a7e3347..aa665817a272 100644 --- a/drivers/usb/serial/mos7720.c +++ b/drivers/usb/serial/mos7720.c @@ -2024,6 +2024,9 @@ static int mos7720_ioctl(struct tty_struct *tty, struct file *file, case TIOCGICOUNT: cnow = mos7720_port->icount; + + memset(&icount, 0, sizeof(struct serial_icounter_struct)); + icount.cts = cnow.cts; icount.dsr = cnow.dsr; icount.rng = cnow.rng; diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c index 1c9b6e9b2386..1a42bc213799 100644 --- a/drivers/usb/serial/mos7840.c +++ b/drivers/usb/serial/mos7840.c @@ -2285,6 +2285,9 @@ static int mos7840_ioctl(struct tty_struct *tty, struct file *file, case TIOCGICOUNT: cnow = mos7840_port->icount; smp_rmb(); + + memset(&icount, 0, sizeof(struct serial_icounter_struct)); + icount.cts = cnow.cts; icount.dsr = cnow.dsr; icount.rng = cnow.rng; -- GitLab