[PATCH net 02/22] can: skb: make echo skb freeing safe in any IRQ context

[Marc Kleine-Budde <mkl@pengutronix.de>]

From: Cunhao Lu <1579567540@qq.com>

can_put_echo_skb() can be called with hardware interrupts disabled. Its
direct drop paths use kfree_skb(), while can_create_echo_skb() uses
kfree_skb() when cloning fails and consume_skb() after a successful clone.
None of these helpers is safe in every IRQ context.

Use dev_kfree_skb_any() for all drop paths and dev_consume_skb_any() when
consuming a successfully cloned skb. This preserves the respective skb drop
and consumed semantics regardless of the caller IRQ context.

Signed-off-by: Cunhao Lu <1579567540@qq.com>
Link: https://patch.msgid.link/tencent_E84809CF236D0137885E7E4E4D58340B3208@qq.com
[mkl: also convert can_dropped_invalid_skb(), can_dev_dropped_skb()]
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/skb.c | 6 +++---
 include/linux/can/dev.h   | 2 +-
 include/linux/can/skb.h   | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 4f7a189de265..e0eac3678a77 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -63,7 +63,7 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 	    (skb->protocol != htons(ETH_P_CAN) &&
 	     skb->protocol != htons(ETH_P_CANFD) &&
 	     skb->protocol != htons(ETH_P_CANXL))) {
-		kfree_skb(skb);
+		dev_kfree_skb_any(skb);
 		return 0;
 	}
 
@@ -91,7 +91,7 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 	} else {
 		/* locking problem with netif_stop_queue() ?? */
 		netdev_err(dev, "%s: BUG! echo_skb %d is occupied!\n", __func__, idx);
-		kfree_skb(skb);
+		dev_kfree_skb_any(skb);
 		return -EBUSY;
 	}
 
@@ -399,7 +399,7 @@ bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb)
 	return false;
 
 inval_skb:
-	kfree_skb(skb);
+	dev_kfree_skb_any(skb);
 	dev->stats.tx_dropped++;
 	return true;
 }
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 6d0710d6f571..346faddee02e 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -176,7 +176,7 @@ static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *s
 	return can_dropped_invalid_skb(dev, skb);
 
 invalid_skb:
-	kfree_skb(skb);
+	dev_kfree_skb_any(skb);
 	dev->stats.tx_dropped++;
 	return true;
 }
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index a70a02967071..78c5870e2f9a 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -76,12 +76,12 @@ static inline struct sk_buff *can_create_echo_skb(struct sk_buff *skb)
 
 	nskb = skb_clone(skb, GFP_ATOMIC);
 	if (unlikely(!nskb)) {
-		kfree_skb(skb);
+		dev_kfree_skb_any(skb);
 		return NULL;
 	}
 
 	can_skb_set_owner(nskb, skb->sk);
-	consume_skb(skb);
+	dev_consume_skb_any(skb);
 	return nskb;
 }
 
-- 
2.53.0