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Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Ido Schimmel , David Ahern , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" ip6_tnl_xmit() and ipip6_tunnel_xmit() run locklessly (dev->lltx == true). ip6gre_err() and ipip6_err() also run locklessly. We need to add READ_ONCE() and WRITE_ONCE() annotations around t->err_count and t->err_time. Signed-off-by: Eric Dumazet --- v2: addressed sashiko's feedback (Jakub). net/ipv6/ip6_gre.c | 8 ++++---- net/ipv6/ip6_tunnel.c | 11 ++++++----- net/ipv6/sit.c | 22 ++++++++++++---------- 3 files changed, 22 insertions(+), 19 deletions(-) diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 365b4059eb20354c256c491a16db0e606e0a9790..a43382000619049df7a3127f5106ca12608b0344 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -445,11 +445,11 @@ static int ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt, return 0; } - if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO)) - t->err_count++; + if (time_before(jiffies, READ_ONCE(t->err_time) + IP6TUNNEL_ERR_TIMEO)) + WRITE_ONCE(t->err_count, READ_ONCE(t->err_count) + 1); else - t->err_count = 1; - t->err_time = jiffies; + WRITE_ONCE(t->err_count, 1); + WRITE_ONCE(t->err_time, jiffies); return 0; } diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 9d1037ac082f6aad36c152ffdbe0f30237b65fc3..3445f81d9957e0ddd3f23d8b550ef5772672dba6 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1104,7 +1104,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, struct ipv6_tel_txoption opt; struct dst_entry *dst = NULL, *ndst = NULL; struct net_device *tdev; - int mtu; + int err_count, mtu; unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0; unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen; unsigned int max_headroom = psh_hlen; @@ -1214,14 +1214,15 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, goto tx_err_dst_release; } - if (t->err_count > 0) { + err_count = READ_ONCE(t->err_count); + if (err_count > 0) { if (time_before(jiffies, - t->err_time + IP6TUNNEL_ERR_TIMEO)) { - t->err_count--; + READ_ONCE(t->err_time) + IP6TUNNEL_ERR_TIMEO)) { + WRITE_ONCE(t->err_count, err_count - 1); dst_link_failure(skb); } else { - t->err_count = 0; + WRITE_ONCE(t->err_count, 0); } } diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index 201347b4e12742451de6d6036281d1abaff0dd84..9c4efc441711f89d3ef8093f4764a5b8083afb99 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -595,11 +595,11 @@ static int ipip6_err(struct sk_buff *skb, u32 info) if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) goto out; - if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) - t->err_count++; + if (time_before(jiffies, READ_ONCE(t->err_time) + IPTUNNEL_ERR_TIMEO)) + WRITE_ONCE(t->err_count, READ_ONCE(t->err_count) + 1); else - t->err_count = 1; - t->err_time = jiffies; + WRITE_ONCE(t->err_count, 1); + WRITE_ONCE(t->err_time, jiffies); out: return err; } @@ -909,8 +909,8 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *tdev; /* Device to other host */ unsigned int max_headroom; /* The extra header space needed */ __be32 dst = tiph->daddr; + int err_count, mtu; struct flowi4 fl4; - int mtu; u8 ttl; u8 protocol = IPPROTO_IPV6; int t_hlen = tunnel->hlen + sizeof(struct iphdr); @@ -986,13 +986,15 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, } } - if (tunnel->err_count > 0) { + err_count = READ_ONCE(tunnel->err_count); + if (err_count > 0) { if (time_before(jiffies, - tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { - tunnel->err_count--; + READ_ONCE(tunnel->err_time) + IPTUNNEL_ERR_TIMEO)) { + WRITE_ONCE(tunnel->err_count, err_count - 1); dst_link_failure(skb); - } else - tunnel->err_count = 0; + } else { + WRITE_ONCE(tunnel->err_count, 0); + } } /* -- 2.54.0.1099.g489fc7bff1-goog