From: Florian Westphal <fw@strlen.de>
Date: Tue, 9 Aug 2022 18:34:02 +0200
Subject: netfilter: nf_tables: fix null deref due to zeroed list head
Git-commit: 580077855a40741cf511766129702d97ff02f4d9
Patch-mainline: v6.0-rc1
References: CVE-2023-1095 bsc#1208777
In nf_tables_updtable, if nf_tables_table_enable returns an error,
nft_trans_destroy is called to free the transaction object.
nft_trans_destroy() calls list_del(), but the transaction was never
placed on a list -- the list head is all zeroes, this results in
a null dereference:
BUG: KASAN: null-ptr-deref in nft_trans_destroy+0x26/0x59
Call Trace:
nft_trans_destroy+0x26/0x59
nf_tables_newtable+0x4bc/0x9bc
[..]
Its sane to assume that nft_trans_destroy() can be called
on the transaction object returned by nft_trans_alloc(), so
make sure the list head is initialised.
Fixes: 55dd6f93076b ("netfilter: nf_tables: use new transaction infrastructure to handle table")
Reported-by: mingi cho <mgcho.minic@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Miroslav Franc <mfranc@suse.cz>
---
net/netfilter/nf_tables_api.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 460b0925ea60..3cc88998b879 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -153,6 +153,7 @@ static struct nft_trans *nft_trans_alloc_gfp(const struct nft_ctx *ctx,
if (trans == NULL)
return NULL;
+ INIT_LIST_HEAD(&trans->list);
trans->msg_type = msg_type;
trans->ctx = *ctx;