Commit ee2640df authored Jun 08, 2022 by Eric Dumazet Committed by Jakub Kicinski Jun 09, 2022

net: add debug checks in napi_consume_skb and __napi_alloc_skb()



Commit 6454eca8 ("net: Use lockdep_assert_in_softirq()
in napi_consume_skb()") added a check in napi_consume_skb()
which is a bit weak.

napi_consume_skb() and __napi_alloc_skb() should only
be used from BH context, not from hard irq or nmi context,
otherwise we could have races.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 7890e2f0

net/core/skbuff.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -560,6 +560,7 @@ struct sk_buff __napi_alloc_skb(struct napi_struct napi, unsigned int len,
		struct sk_buff *skb;
		void *data;

		DEBUG_NET_WARN_ON_ONCE(!in_softirq());
		len += NET_SKB_PAD + NET_IP_ALIGN;

		/* If requested length is either too small or too big,
		@@ -981,7 +982,7 @@ void napi_consume_skb(struct sk_buff *skb, int budget)
		return;
		}

		lockdep_assert_in_softirq();
		DEBUG_NET_WARN_ON_ONCE(!in_softirq());

		if (!skb_unref(skb))
		return;