From ae64438be1923e3c1102d90fd41db7afcfaf54cc Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Wed, 2 Nov 2022 10:54:31 +0100 Subject: can: dev: fix skb drop check In commit a6d190f8c767 ("can: skb: drop tx skb if in listen only mode") the priv->ctrlmode element is read even on virtual CAN interfaces that do not create the struct can_priv at startup. This out-of-bounds read may lead to CAN frame drops for virtual CAN interfaces like vcan and vxcan. This patch mainly reverts the original commit and adds a new helper for CAN interface drivers that provide the required information in struct can_priv. Fixes: a6d190f8c767 ("can: skb: drop tx skb if in listen only mode") Reported-by: Dariusz Stojaczyk Cc: Vincent Mailhol Cc: Max Staudt Signed-off-by: Oliver Hartkopp Acked-by: Vincent Mailhol Link: https://lore.kernel.org/all/20221102095431.36831-1-socketcan@hartkopp.net Cc: stable@vger.kernel.org # 6.0.x [mkl: patch pch_can, too] Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/skb.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) (limited to 'drivers/net/can/dev/skb.c') diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c index 791a51e2f5d6..241ec636e91f 100644 --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -5,7 +5,6 @@ */ #include -#include #include #define MOD_DESC "CAN device driver interface" @@ -337,8 +336,6 @@ static bool can_skb_headroom_valid(struct net_device *dev, struct sk_buff *skb) /* Drop a given socketbuffer if it does not contain a valid CAN frame. */ bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb) { - struct can_priv *priv = netdev_priv(dev); - switch (ntohs(skb->protocol)) { case ETH_P_CAN: if (!can_is_can_skb(skb)) @@ -359,13 +356,8 @@ bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb) goto inval_skb; } - if (!can_skb_headroom_valid(dev, skb)) { + if (!can_skb_headroom_valid(dev, skb)) goto inval_skb; - } else if (priv->ctrlmode & CAN_CTRLMODE_LISTENONLY) { - netdev_info_once(dev, - "interface in listen only mode, dropping skb\n"); - goto inval_skb; - } return false; -- cgit v1.2.3