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| author | Patrick McHardy <kaber@trash.net> | 2011-02-14 19:35:07 +0300 |
|---|---|---|
| committer | Patrick McHardy <kaber@trash.net> | 2011-02-14 19:35:07 +0300 |
| commit | de9963f0f2dfad128b26ae7bf6005f5948416a6d (patch) | |
| tree | 73b45541d33e86600cd10e4be43298864f2b6a1a | |
| parent | c317428644c0af137d80069ab178cd797da3be45 (diff) | |
| download | linux-de9963f0f2dfad128b26ae7bf6005f5948416a6d.tar.xz | |
netfilter: nf_iterate: fix incorrect RCU usage
As noticed by Eric, nf_iterate doesn't use RCU correctly by
accessing the prev pointer of a RCU protected list element when
a verdict of NF_REPEAT is issued.
Fix by jumping backwards to the hook invocation directly instead
of loading the previous list element before continuing the list
iteration.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
| -rw-r--r-- | net/netfilter/core.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/netfilter/core.c b/net/netfilter/core.c index 32fcbe290c04..4aa614b8a96a 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -133,6 +133,7 @@ unsigned int nf_iterate(struct list_head *head, /* Optimization: we don't need to hold module reference here, since function can't sleep. --RR */ +repeat: verdict = elem->hook(hook, skb, indev, outdev, okfn); if (verdict != NF_ACCEPT) { #ifdef CONFIG_NETFILTER_DEBUG @@ -145,7 +146,7 @@ unsigned int nf_iterate(struct list_head *head, #endif if (verdict != NF_REPEAT) return verdict; - *i = (*i)->prev; + goto repeat; } } return NF_ACCEPT; |