From: Richard Palethorpe <rpalethorpe@suse.com> mainline inclusion from mainline-v5.7 commit b9258a2cece4ec1f020715fe3554bc2e360f6264 category: bugfix bugzilla: 13690 CVE: CVE-2020-11494 ------------------------------------------------- struct can_frame contains some padding which is not explicitly zeroed in slc_bump. This uninitialized data will then be transmitted if the stack initialization hardening feature is not enabled (CONFIG_INIT_STACK_ALL). This commit just zeroes the whole struct including the padding. Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com> Fixes: a1044e36e457 ("can: add slcan driver for serial/USB-serial CAN adapters") Reviewed-by: Kees Cook <keescook@chromium.org> Cc: linux-can@vger.kernel.org Cc: netdev@vger.kernel.org Cc: security@kernel.org Cc: wg@grandegger.com Cc: mkl@pengutronix.de Cc: davem@davemloft.net Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Wenan Mao <maowenan@huawei.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/net/can/slcan.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index db96078..f99cd94 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -147,7 +147,7 @@ static void slc_bump(struct slcan *sl) u32 tmpid; char *cmd = sl->rbuff; - cf.can_id = 0; + memset(&cf, 0, sizeof(cf)); switch (*cmd) { case 'r': @@ -186,8 +186,6 @@ static void slc_bump(struct slcan *sl) else return; - *(u64 *) (&cf.data) = 0; /* clear payload */ - /* RTR frames may have a dlc > 0 but they never have any data bytes */ if (!(cf.can_id & CAN_RTR_FLAG)) { for (i = 0; i < cf.can_dlc; i++) { -- 1.8.3