# \[PATCH net 09/14\] can: skb: make CAN skb allocation failure paths IRQ-safe

- From: Marc Kleine-Budde \<mkl@pengutronix.de\>
- Date: 2026-08-26 12:10:48 
- List: netdev
- Page: https://ratatoskr.run/netdev/2026/08/17464329
- Thread: https://ratatoskr.run/netdev/2026/08/17464352/t.md

```text
From: Cunhao Lu <redacted>

The CAN skb allocation helpers are used from hardware interrupt receive
handlers. If can_skb_ext_add() fails, they release the newly allocated skb
with kfree_skb(), which is not safe in hardware interrupt context.

Use dev_kfree_skb_any() for the allocation failure paths in
alloc_can_skb(), alloc_canfd_skb(), and alloc_canxl_skb().

Fixes: 96ea3a1e2d31 ("can: add CAN skb extension infrastructure")
Cc: <redacted>
Signed-off-by: Cunhao Lu <redacted>
Link: https://patch.msgid.link/tencent_C825C17D442F801351CE2FBC4984064B4605@qq.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/skb.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 0ed8057a3cb2..c7be21ed70dd 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -224,7 +224,7 @@ struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
 
 	csx = can_skb_ext_add(skb);
 	if (!csx) {
-		kfree_skb(skb);
+		dev_kfree_skb_any(skb);
 		goto out_error_cc;
 	}
 
@@ -255,7 +255,7 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 
 	csx = can_skb_ext_add(skb);
 	if (!csx) {
-		kfree_skb(skb);
+		dev_kfree_skb_any(skb);
 		goto out_error_fd;
 	}
 
@@ -293,7 +293,7 @@ struct sk_buff *alloc_canxl_skb(struct net_device *dev,
 
 	csx = can_skb_ext_add(skb);
 	if (!csx) {
-		kfree_skb(skb);
+		dev_kfree_skb_any(skb);
 		goto out_error_xl;
 	}
 
-- 
2.53.0

```
