From: Richard Palethorpe Date: Wed, 1 Apr 2020 10:06:39 +0000 (+0200) Subject: slcan: Don't transmit uninitialized stack data in padding X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=925c631e84d77a72188101258878ac58a646d540;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git slcan: Don't transmit uninitialized stack data in padding [ Upstream commit b9258a2cece4ec1f020715fe3554bc2e360f6264 ] 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 Fixes: a1044e36e457 ("can: add slcan driver for serial/USB-serial CAN adapters") Reviewed-by: Kees Cook 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index 94b37c60fdd0..d0435c7631ff 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++) {