From: Richard Palethorpe rpalethorpe@suse.com
mainline inclusion from mainline-v5.7 commit b9258a2cece4ec1f020715fe3554bc2e360f6264 category: bugfix bugzilla: 13690 CVE: CVE-2020-11494
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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++) {