ipv4: tcp: ip_send_unicast_reply() is not BH safe
I forgot that ip_send_unicast_reply() is not BH safe (yet).
Disabling preemption before calling it was not a good move.
Fixes: c10d9310edf5 ("tcp: do not assume TCP code is non preemptible")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andres Lagar-Cavilla <andreslc@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index a7ab947..8219d0d 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -692,7 +692,7 @@
offsetof(struct inet_timewait_sock, tw_bound_dev_if));
arg.tos = ip_hdr(skb)->tos;
- preempt_disable();
+ local_bh_disable();
ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
skb, &TCP_SKB_CB(skb)->header.h4.opt,
ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
@@ -700,7 +700,7 @@
__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
__TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
- preempt_enable();
+ local_bh_enable();
#ifdef CONFIG_TCP_MD5SIG
out:
@@ -776,14 +776,14 @@
if (oif)
arg.bound_dev_if = oif;
arg.tos = tos;
- preempt_disable();
+ local_bh_disable();
ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
skb, &TCP_SKB_CB(skb)->header.h4.opt,
ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
&arg, arg.iov[0].iov_len);
__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
- preempt_enable();
+ local_bh_enable();
}
static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)