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authorDan Rosenberg <drosenberg@vsecurity.com>2010-09-15 17:44:16 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2010-09-20 16:05:00 -0700
commita0846f1868b11cd827bdfeaf4527d8b1b1c0b098 (patch)
tree01ca49ce4f0c11d1a8274dce1484f039a41781e9
parentfc8f2a7608d855b911e35a33e771e6358c705c43 (diff)
downloadlinux-a0846f1868b11cd827bdfeaf4527d8b1b1c0b098.tar.gz
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 <dan.j.rosenberg@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

-rw-r--r--drivers/usb/serial/mos7720.c3
-rw-r--r--drivers/usb/serial/mos7840.c3
2 files changed, 6 insertions, 0 deletions
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;