[PATCH 4/8] netfilter: nf_tables: free chain context when BINDING flag is missing

[Pablo Neira Ayuso]

From: Florian Westphal <f...@strlen.de>

syzbot found a memory leak in nf_tables_addchain() because the chain
object is not free'd correctly on error.

Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Reported-by: syzbot+c99868fde67014f7e...@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <f...@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index d878e34e3354..fd814e514f94 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2018,8 +2018,10 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 
family, u8 genmask,
        if (nla[NFTA_CHAIN_NAME]) {
                chain->name = nla_strdup(nla[NFTA_CHAIN_NAME], GFP_KERNEL);
        } else {
-               if (!(flags & NFT_CHAIN_BINDING))
-                       return -EINVAL;
+               if (!(flags & NFT_CHAIN_BINDING)) {
+                       err = -EINVAL;
+                       goto err1;
+               }
 
                snprintf(name, sizeof(name), "__chain%llu", ++chain_id);
                chain->name = kstrdup(name, GFP_KERNEL);
-- 
2.20.1