From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Wed, 18 Mar 2020 00:14:58 +0000 (+0100)
Subject: netfilter: nf_tables: fix double-free on set expression from the error path
X-Git-Tag: v5.15~4200^2~12^2~24
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=772f4e82b3ffa1eb7412cd531f718a96a0e5474b;p=platform%2Fkernel%2Flinux-starfive.git

netfilter: nf_tables: fix double-free on set expression from the error path

After copying the expression to the set element extension, release the
expression and reset the pointer to avoid a double-free from the error
path.

Fixes: 409444522976 ("netfilter: nf_tables: add elements with stateful expressions")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index f1910cd..29ad33e 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5133,6 +5133,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	if (expr) {
 		memcpy(nft_set_ext_expr(ext), expr, expr->ops->size);
 		kfree(expr);
+		expr = NULL;
 	}
 
 	trans = nft_trans_elem_alloc(ctx, NFT_MSG_NEWSETELEM, set);