From: Marc Kleine-Budde Date: Wed, 9 Oct 2019 14:03:18 +0000 (+0200) Subject: can: rx-offload: can_rx_offload_offload_one(): do not increase the skb_queue beyond... X-Git-Tag: v4.19.88~293 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b83d4e4899d647bab00e1f5f544a8e4900120a7d;p=thirdparty%2Fkernel%2Fstable.git can: rx-offload: can_rx_offload_offload_one(): do not increase the skb_queue beyond skb_queue_len_max [ Upstream commit a2dc3f5e1022a5ede8af9ab89a144f1e69db8636 ] The skb_queue is a linked list, holding the skb to be processed in the next NAPI call. Without this patch, the queue length in can_rx_offload_offload_one() is limited to skb_queue_len_max + 1. As the skb_queue is a linked list, no array or other resources are accessed out-of-bound, however this behaviour is counterintuitive. This patch limits the rx-offload skb_queue length to skb_queue_len_max. Fixes: d254586c3453 ("can: rx-offload: Add support for HW fifo based irq offloading") Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/rx-offload.c index a90005eac8b17..e32b65599a5f2 100644 --- a/drivers/net/can/rx-offload.c +++ b/drivers/net/can/rx-offload.c @@ -124,7 +124,7 @@ static struct sk_buff *can_rx_offload_offload_one(struct can_rx_offload *offload int ret; /* If queue is full or skb not available, read to discard mailbox */ - if (likely(skb_queue_len(&offload->skb_queue) <= + if (likely(skb_queue_len(&offload->skb_queue) < offload->skb_queue_len_max)) skb = alloc_can_skb(offload->dev, &cf);