4.4-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 215ab0f021c9fea3c18b75e7d522400ee6a49990 ]
After commit d6990976af7c5d8f55903bfb4289b6fb030bf754 ("vti6: fix PMTU caching and reporting on xmit"), some too big skbs might be potentially passed down to __xfrm6_output, causing it to fail to transmit but not free the skb, causing a leak of skb, and consequentially a leak of dst references.
After running pmtu.sh, that shows as failure to unregister devices in a namespace:
[ 311.397671] unregister_netdevice: waiting for veth_b to become free. Usage count = 1
The fix is to call kfree_skb in case of transmit failures.
Fixes: dd767856a36e ("xfrm6: Don't call icmpv6_send on local error") Signed-off-by: Thadeu Lima de Souza Cascardo cascardo@canonical.com Reviewed-by: Sabrina Dubroca sd@queasysnail.net Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/xfrm6_output.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c index 4d09ce6fa90e..64862c5084ee 100644 --- a/net/ipv6/xfrm6_output.c +++ b/net/ipv6/xfrm6_output.c @@ -165,9 +165,11 @@ static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
if (toobig && xfrm6_local_dontfrag(skb)) { xfrm6_local_rxpmtu(skb, mtu); + kfree_skb(skb); return -EMSGSIZE; } else if (!skb->ignore_df && toobig && skb->sk) { xfrm_local_error(skb, mtu); + kfree_skb(skb); return -EMSGSIZE; }