diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-05-31 16:26:33 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-06-04 04:50:08 +0300 |
| commit | db0090c6eb12c31246438b7fe2a8f1b833e7a653 (patch) | |
| tree | d7ac778dd6ff370c7b38190bfc2badc6a929bce1 | |
| parent | 2fe40483ec257de2a0d819ef88e3e76c7e261319 (diff) | |
| download | linux-db0090c6eb12c31246438b7fe2a8f1b833e7a653.tar.xz | |
net: ipv6: rpl_iptunnel: block BH in rpl_output() and rpl_input()
As explained in commit 1378817486d6 ("tipc: block BH
before using dst_cache"), net/core/dst_cache.c
helpers need to be called with BH disabled.
Disabling preemption in rpl_output() is not good enough,
because rpl_output() is called from process context,
lwtunnel_output() only uses rcu_read_lock().
We might be interrupted by a softirq, re-enter rpl_output()
and corrupt dst_cache data structures.
Fix the race by using local_bh_disable() instead of
preempt_disable().
Apply a similar change in rpl_input().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Aring <aahringo@redhat.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240531132636.2637995-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv6/rpl_iptunnel.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c index a013b92cbb86..2c83b7586422 100644 --- a/net/ipv6/rpl_iptunnel.c +++ b/net/ipv6/rpl_iptunnel.c @@ -212,9 +212,9 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb) if (unlikely(err)) goto drop; - preempt_disable(); + local_bh_disable(); dst = dst_cache_get(&rlwt->cache); - preempt_enable(); + local_bh_enable(); if (unlikely(!dst)) { struct ipv6hdr *hdr = ipv6_hdr(skb); @@ -234,9 +234,9 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb) goto drop; } - preempt_disable(); + local_bh_disable(); dst_cache_set_ip6(&rlwt->cache, dst, &fl6.saddr); - preempt_enable(); + local_bh_enable(); } skb_dst_drop(skb); @@ -268,23 +268,21 @@ static int rpl_input(struct sk_buff *skb) return err; } - preempt_disable(); + local_bh_disable(); dst = dst_cache_get(&rlwt->cache); - preempt_enable(); if (!dst) { ip6_route_input(skb); dst = skb_dst(skb); if (!dst->error) { - preempt_disable(); dst_cache_set_ip6(&rlwt->cache, dst, &ipv6_hdr(skb)->saddr); - preempt_enable(); } } else { skb_dst_drop(skb); skb_dst_set(skb, dst); } + local_bh_enable(); err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err)) |