Messages in this thread Patch in this message | | | Subject | [PATCH] drivers/usb/serial/mos*: prevent reading uninitialized stack memory | From | Dan Rosenberg <> | Date | Wed, 15 Sep 2010 17:44:16 -0400 |
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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>
diff -urp linux-2.6.35.4.orig/drivers/usb/serial/mos7720.c linux-2.6.35.4/drivers/usb/serial/mos7720.c --- linux-2.6.35.4.orig/drivers/usb/serial/mos7720.c 2010-08-26 19:47:12.000000000 -0400 +++ linux-2.6.35.4/drivers/usb/serial/mos7720.c 2010-09-15 11:42:01.877375361 -0400 @@ -2024,6 +2024,9 @@ static int mos7720_ioctl(struct tty_stru 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 -urp linux-2.6.35.4.orig/drivers/usb/serial/mos7840.c linux-2.6.35.4/drivers/usb/serial/mos7840.c --- linux-2.6.35.4.orig/drivers/usb/serial/mos7840.c 2010-08-26 19:47:12.000000000 -0400 +++ linux-2.6.35.4/drivers/usb/serial/mos7840.c 2010-09-15 11:42:39.237375173 -0400 @@ -2273,6 +2273,9 @@ static int mos7840_ioctl(struct tty_stru 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;
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