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| author | Eric Dumazet <edumazet@google.com> | 2024-05-31 13:26:33 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-07-25 09:49:10 +0200 |
| commit | 5f7ca378691d607103dec266e15c361d8874938b (patch) | |
| tree | 2c837126ec7cb8218f4ec9453e76c09a1441ee63 /net | |
| parent | 949a179da47d1231dd6862a4582b261cac31d056 (diff) | |
| download | linux-5f7ca378691d607103dec266e15c361d8874938b.tar.gz linux-5f7ca378691d607103dec266e15c361d8874938b.tar.bz2 linux-5f7ca378691d607103dec266e15c361d8874938b.zip | |
net: ipv6: rpl_iptunnel: block BH in rpl_output() and rpl_input()
[ Upstream commit db0090c6eb12c31246438b7fe2a8f1b833e7a653 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -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 ff691d9f4a04..26adbe7f8a2f 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); @@ -268,9 +268,8 @@ static int rpl_input(struct sk_buff *skb) return err; } - preempt_disable(); + local_bh_disable(); dst = dst_cache_get(&rlwt->cache); - preempt_enable(); skb_dst_drop(skb); @@ -278,14 +277,13 @@ static int rpl_input(struct sk_buff *skb) 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_set(skb, dst); } + local_bh_enable(); err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err)) |