Messages in this thread Patch in this message | | | From | Colin King <> | Subject | [PATCH][next] netfilter: nf_tables: Fix dereference of null pointer flow | Date | Thu, 24 Jun 2021 20:57:18 +0100 |
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From: Colin Ian King <colin.king@canonical.com>
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: 3c5e44622011 ("netfilter: nf_tables: memleak in hw offload abort path") Signed-off-by: Colin Ian King <colin.king@canonical.com> --- net/netfilter/nf_tables_api.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 390d4466567f..de182d1f7c4e 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3446,7 +3446,8 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info, return 0; err_destroy_flow_rule: - nft_flow_rule_destroy(flow); + if (flow) + nft_flow_rule_destroy(flow); err_release_rule: nf_tables_rule_release(&ctx, rule); err_release_expr: -- 2.31.1
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