Message ID | 20181208112246.16622-1-willemdebruijn.kernel@gmail.com |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
Series | [net-next] ip: silence udp zerocopy smatch false positive | expand |
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Date: Sat, 8 Dec 2018 06:22:46 -0500 > From: Willem de Bruijn <willemb@google.com> > > extra_uref is used in __ip(6)_append_data only if uarg is set. > > Smatch sees that the variable is passed to sock_zerocopy_put_abort. > This function accesses it only when uarg is set, but smatch cannot > infer this. > > Make this dependency explicit. > > Fixes: 52900d22288e ("udp: elide zerocopy operation in hot path") > Signed-off-by: Willem de Bruijn <willemb@google.com> I looked and can't figure out a better way to fix this :) Applied, thanks Willem.
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 78f028bdad30b..ab6618036afed 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1130,7 +1130,8 @@ static int __ip_append_data(struct sock *sk, error_efault: err = -EFAULT; error: - sock_zerocopy_put_abort(uarg, extra_uref); + if (uarg) + sock_zerocopy_put_abort(uarg, extra_uref); cork->length -= length; IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 6592a39e5ec10..be25b34dc5c2f 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1575,7 +1575,8 @@ static int __ip6_append_data(struct sock *sk, error_efault: err = -EFAULT; error: - sock_zerocopy_put_abort(uarg, extra_uref); + if (uarg) + sock_zerocopy_put_abort(uarg, extra_uref); cork->length -= length; IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc);