From: Eric Dumazet <edumazet@xxxxxxxxxx>
In the prep work I did before enabling BH while handling socket backlog,
I missed two points in DCCP :
1) dccp_v4_ctl_send_reset() uses bh_lock_sock(), assuming BH were
blocked. It is not anymore always true.
2) dccp_v4_route_skb() was using __IP_INC_STATS() instead of
IP_INC_STATS()
A similar fix was done for TCP, in commit 47dcc20a39d0
("ipv4: tcp: ip_send_unicast_reply() is not BH safe")
Fixes: 7309f8821fd6 ("dccp: do not assume DCCP code is non preemptible")
Fixes: 5413d1babe8f ("net: do not block BH while processing socket backlog")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
---
net/dccp/ipv4.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 5c7e413a3ae407e67565b48a8bd6f43e3b02de4d..25dd25b47d4163625e092c8b96715bb709d85891 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -462,7 +462,7 @@ static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
rt = ip_route_output_flow(net, &fl4, sk);
if (IS_ERR(rt)) {
- __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
+ IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
return NULL;
}
@@ -527,17 +527,19 @@ static void dccp_v4_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
rxiph->daddr);
skb_dst_set(skb, dst_clone(dst));
+ local_bh_disable();
bh_lock_sock(ctl_sk);
err = ip_build_and_send_pkt(skb, ctl_sk,
rxiph->daddr, rxiph->saddr, NULL);
bh_unlock_sock(ctl_sk);
if (net_xmit_eval(err) == 0) {
- DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
- DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
+ __DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
+ __DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
}
+ local_bh_enable();
out:
- dst_release(dst);
+ dst_release(dst);
}
static void dccp_v4_reqsk_destructor(struct request_sock *req)
--
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