Commit 4ca041f9 authored Jun 24, 2021 by Colin Ian King Committed by Pablo Neira Ayuso Jul 02, 2021

netfilter: nf_tables: Fix dereference of null pointer flow



In the case where chain->flags & NFT_CHAIN_HW_OFFLOAD is false then
nft_flow_rule_create is not called and flow is NULL. The subsequent
error handling execution via label err_destroy_flow_rule will lead
to a null pointer dereference on flow when calling nft_flow_rule_destroy.
Since the error path to err_destroy_flow_rule has to cater for null
and non-null flows, only call nft_flow_rule_destroy if flow is non-null
to fix this issue.

Addresses-Coverity: ("Explicity null dereference")
Fixes: 3c5e4462 ("netfilter: nf_tables: memleak in hw offload abort path")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

parent e15d4cdf

net/netfilter/nf_tables_api.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -3446,6 +3446,7 @@ static int nf_tables_newrule(struct sk_buff skb, const struct nfnl_info info,
		return 0;

		err_destroy_flow_rule:
		if (flow)
		nft_flow_rule_destroy(flow);
		err_release_rule:
		nf_tables_rule_release(&ctx, rule);