diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-06-30 12:19:28 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-02 14:32:29 -0700 |
| commit | f1c5fd34891a1c242885f48c2e4dc52df180f311 (patch) | |
| tree | 57b3b2594bd1abb26ae65a0c65fcdb2a571900a1 | |
| parent | 8f2b2282d04a5d5bcbec22f91572bb6803cfc771 (diff) | |
net: dst: annotate data-races around dst->input
dst_dev_put() can overwrite dst->input while other
cpus might read this field (for instance from dst_input())
Add READ_ONCE()/WRITE_ONCE() annotations to suppress
potential issues.
We will likely need full RCU protection later.
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/20250630121934.3399505-5-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 bef2f41c7220..c0f8b6d8e707 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -468,7 +468,7 @@ INDIRECT_CALLABLE_DECLARE(int ip_local_deliver(struct sk_buff *)); /* Input packet from network to transport. */ static inline int dst_input(struct sk_buff *skb) { - return INDIRECT_CALL_INET(skb_dst(skb)->input, + return INDIRECT_CALL_INET(READ_ONCE(skb_dst(skb)->input), ip6_input, ip_local_deliver, skb); } diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h index c306ebe379a0..eaac07d50595 100644 --- a/include/net/lwtunnel.h +++ b/include/net/lwtunnel.h @@ -142,8 +142,8 @@ static inline void lwtunnel_set_redirect(struct dst_entry *dst) dst->output = lwtunnel_output; } if (lwtunnel_input_redirect(dst->lwtstate)) { - dst->lwtstate->orig_input = dst->input; - dst->input = lwtunnel_input; + dst->lwtstate->orig_input = READ_ONCE(dst->input); + WRITE_ONCE(dst->input, lwtunnel_input); } } #else diff --git a/net/core/dst.c b/net/core/dst.c index 8f2a3138d60c..13c629dc7123 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -148,7 +148,7 @@ void dst_dev_put(struct dst_entry *dst) WRITE_ONCE(dst->obsolete, DST_OBSOLETE_DEAD); if (dst->ops->ifdown) dst->ops->ifdown(dst, dev); - dst->input = dst_discard; + WRITE_ONCE(dst->input, dst_discard); dst->output = dst_discard_out; dst->dev = blackhole_netdev; netdev_ref_replace(dev, blackhole_netdev, &dst->dev_tracker, diff --git a/net/ipv4/route.c b/net/ipv4/route.c index d7a534a5f1ff..75a1f9eabd6b 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1687,7 +1687,7 @@ struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) else if (rt->rt_gw_family == AF_INET6) new_rt->rt_gw6 = rt->rt_gw6; - new_rt->dst.input = rt->dst.input; + new_rt->dst.input = READ_ONCE(rt->dst.input); new_rt->dst.output = rt->dst.output; new_rt->dst.error = rt->dst.error; new_rt->dst.lastuse = jiffies; |