On Tue, 14 Aug 2012 02:47:42 +0400 Denis Efremov <[email protected]> wrote:
> As it noted in the comment before the br_handle_frame_finish > function, this function should be called under rcu_read_lock. > > The problem callgraph: > br_dev_xmit -> br_nf_pre_routing_finish_bridge_slow -> > -> br_handle_frame_finish -> br_port_get_rcu -> rcu_dereference > > And in this case there is no read-lock section. > I have put lock/unlock in br_nf_pre_routing_finish_bridge_slow, > as the only function that calls it(for now) - is br_dev_xmit. > > Found by Linux Driver Verification project (linuxtesting.org). > > Signed-off-by: Denis Efremov <[email protected]> > --- > include/linux/netfilter_bridge.h | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/include/linux/netfilter_bridge.h > b/include/linux/netfilter_bridge.h > index 31d2844..ceb048e 100644 > --- a/include/linux/netfilter_bridge.h > +++ b/include/linux/netfilter_bridge.h > @@ -79,6 +79,7 @@ extern int br_handle_frame_finish(struct sk_buff *skb); > /* Only used in br_device.c */ > static inline int br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb) > { > + int res; > struct nf_bridge_info *nf_bridge = skb->nf_bridge; > > skb_pull(skb, ETH_HLEN); > @@ -86,7 +87,10 @@ static inline int > br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb) > skb_copy_to_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN), > skb->nf_bridge->data, ETH_HLEN-ETH_ALEN); > skb->dev = nf_bridge->physindev; > - return br_handle_frame_finish(skb); > + rcu_read_lock(); > + res = br_handle_frame_finish(skb); > + rcu_read_unlock(); > + return res; > } > > /* This is called by the IP fragmenting code and it ensures there is Why not just move the rcu_read_lock() in br_dev_xmit earlier? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
