ip: silence udp zerocopy smatch false positive
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 78f028b..ab66180 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 6592a39..be25b34 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);
