From 8a2df34b5bf652566f2889d9fa321f3b398547ef Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 9 Aug 2022 18:34:02 +0200 Subject: [PATCH] netfilter: nf_tables: fix null deref due to zeroed list head commit 580077855a40741cf511766129702d97ff02f4d9 upstream. 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 Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- 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 5c10a1b..13d14fc 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; -- 2.7.4