netfilter: nfnetlink: use original skbuff when acking batches

Since bd678e09dc17 ("netfilter: nfnetlink: fix splat due to incorrect
socket memory accounting in skbuff clones"), we don't manually attach
the sk to the skbuff clone anymore, so we have to use the original
skbuff from netlink_ack() which needs to access the sk pointer.

Fixes: bd678e09dc17 ("netfilter: nfnetlink: fix splat due to incorrect socket memory accounting in skbuff clones")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index a7ba23353dab938b4048095e50da9eb463dfc477..62e92af2384a175af68323a3a3cd814e99b95e91 100644 (file)
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -311,14 +311,14 @@ replay:
 #endif
                {
                        nfnl_unlock(subsys_id);
-                       netlink_ack(skb, nlh, -EOPNOTSUPP);
+                       netlink_ack(oskb, nlh, -EOPNOTSUPP);
                        return kfree_skb(skb);
                }
        }
 
        if (!ss->commit || !ss->abort) {
                nfnl_unlock(subsys_id);
-               netlink_ack(skb, nlh, -EOPNOTSUPP);
+               netlink_ack(oskb, nlh, -EOPNOTSUPP);
                return kfree_skb(skb);
        }
 
@@ -406,7 +406,7 @@ ack:
                                 * pointing to the batch header.
                                 */
                                nfnl_err_reset(&err_list);
-                               netlink_ack(skb, nlmsg_hdr(oskb), -ENOMEM);
+                               netlink_ack(oskb, nlmsg_hdr(oskb), -ENOMEM);
                                status |= NFNL_BATCH_FAILURE;
                                goto done;
                        }