diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-06-30 12:19:29 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-02 14:32:30 -0700 |
| commit | 2dce8c52a98995c4719def6f88629ab1581c0b82 (patch) | |
| tree | dc7bcd58ec7b1544d804b173160aff812941a9b1 | |
| parent | f1c5fd34891a1c242885f48c2e4dc52df180f311 (diff) | |
net: dst: annotate data-races around dst->output
dst_dev_put() can overwrite dst->output while other
cpus might read this field (for instance from dst_output())
Add READ_ONCE()/WRITE_ONCE() annotations to suppress
potential issues.
We will likely need RCU protection in the future.
Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/net/dst.h | 2 | ||||
| -rw-r--r-- | include/net/lwtunnel.h | 4 | ||||
| -rw-r--r-- | net/core/dst.c | 2 | ||||
| -rw-r--r-- | net/ipv4/route.c | 2 |
4 files changed, 5 insertions, 5 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index c0f8b6d8e707..b6acfde7d587 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -458,7 +458,7 @@ INDIRECT_CALLABLE_DECLARE(int ip_output(struct net *, struct sock *, /* Output packet to network from transport. */ static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb) { - return INDIRECT_CALL_INET(skb_dst(skb)->output, + return INDIRECT_CALL_INET(READ_ONCE(skb_dst(skb)->output), ip6_output, ip_output, net, sk, skb); } diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h index eaac07d50595..26232f603e33 100644 --- a/include/net/lwtunnel.h +++ b/include/net/lwtunnel.h @@ -138,8 +138,8 @@ int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, static inline void lwtunnel_set_redirect(struct dst_entry *dst) { if (lwtunnel_output_redirect(dst->lwtstate)) { - dst->lwtstate->orig_output = dst->output; - dst->output = lwtunnel_output; + dst->lwtstate->orig_output = READ_ONCE(dst->output); + WRITE_ONCE(dst->output, lwtunnel_output); } if (lwtunnel_input_redirect(dst->lwtstate)) { dst->lwtstate->orig_input = READ_ONCE(dst->input); diff --git a/net/core/dst.c b/net/core/dst.c index 13c629dc7123..52e824e57c17 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -149,7 +149,7 @@ void dst_dev_put(struct dst_entry *dst) if (dst->ops->ifdown) dst->ops->ifdown(dst, dev); WRITE_ONCE(dst->input, dst_discard); - dst->output = dst_discard_out; + WRITE_ONCE(dst->output, dst_discard_out); dst->dev = blackhole_netdev; netdev_ref_replace(dev, blackhole_netdev, &dst->dev_tracker, GFP_ATOMIC); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 75a1f9eabd6b..ce6aba4f01ff 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1688,7 +1688,7 @@ struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) new_rt->rt_gw6 = rt->rt_gw6; new_rt->dst.input = READ_ONCE(rt->dst.input); - new_rt->dst.output = rt->dst.output; + new_rt->dst.output = READ_ONCE(rt->dst.output); new_rt->dst.error = rt->dst.error; new_rt->dst.lastuse = jiffies; new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); |