diff mbox series

[5.10,28/38] netfilter: nf_tables: initialize registers in nft_do_chain()

Message ID 20220325150420.557842097@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH March 25, 2022, 3:05 p.m. UTC 
From: Pablo Neira Ayuso <pablo@netfilter.org>

commit 4c905f6740a365464e91467aa50916555b28213d upstream.

Initialize registers to avoid stack leak into userspace.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/netfilter/nf_tables_core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Pavel Machek March 26, 2022, 8:10 p.m. UTC | #1 
On Fri 2022-03-25 16:05:12, Greg Kroah-Hartman wrote:
> From: Pablo Neira Ayuso <pablo@netfilter.org>
> 
> commit 4c905f6740a365464e91467aa50916555b28213d upstream.
> 
> Initialize registers to avoid stack leak into userspace.

For that, memset() is better, due to padding. There is no padding in
the struct AFAICT, still memset would be better for robustness.

> --- a/net/netfilter/nf_tables_core.c
> +++ b/net/netfilter/nf_tables_core.c
> @@ -162,7 +162,7 @@ nft_do_chain(struct nft_pktinfo *pkt, vo
>  	struct nft_rule *const *rules;
>  	const struct nft_rule *rule;
>  	const struct nft_expr *expr, *last;
> -	struct nft_regs regs;
> +	struct nft_regs regs = {};
>  	unsigned int stackptr = 0;
>  	struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE];
>  	bool genbit = READ_ONCE(net->nft.gencursor);
> 

Best regards,
							Pavel
diff mbox series

Patch

--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -162,7 +162,7 @@  nft_do_chain(struct nft_pktinfo *pkt, vo
 	struct nft_rule *const *rules;
 	const struct nft_rule *rule;
 	const struct nft_expr *expr, *last;
-	struct nft_regs regs;
+	struct nft_regs regs = {};
 	unsigned int stackptr = 0;
 	struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE];
 	bool genbit = READ_ONCE(net->nft.gencursor);