From 1894d7cb6997c906ec3108e49944e35b084141fa Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Wed, 8 Mar 2017 22:54:18 +0800 Subject: netfilter: nf_tables: fix mismatch in big-endian system commit 10596608c4d62cb8c1c2b806debcbd32fe657e71 upstream. Currently, there are two different methods to store an u16 integer to the u32 data register. For example: u32 *dest = ®s->data[priv->dreg]; 1. *dest = 0; *(u16 *) dest = val_u16; 2. *dest = val_u16; For method 1, the u16 value will be stored like this, either in big-endian or little-endian system: 0 15 31 +-+-+-+-+-+-+-+-+-+-+-+-+ | Value | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+ For method 2, in little-endian system, the u16 value will be the same as listed above. But in big-endian system, the u16 value will be stored like this: 0 15 31 +-+-+-+-+-+-+-+-+-+-+-+-+ | 0 | Value | +-+-+-+-+-+-+-+-+-+-+-+-+ So later we use "memcmp(®s->data[priv->sreg], data, 2);" to do compare in nft_cmp, nft_lookup expr ..., method 2 will get the wrong result in big-endian system, as 0~15 bits will always be zero. For the similar reason, when loading an u16 value from the u32 data register, we should use "*(u16 *) sreg;" instead of "(u16)*sreg;", the 2nd method will get the wrong value in the big-endian system. So introduce some wrapper functions to store/load an u8 or u16 integer to/from the u32 data register, and use them in the right place. Signed-off-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nft_meta.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-) (limited to 'net/netfilter/nft_meta.c') diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c index 7c3395513ff0..cec8dc0e5e6f 100644 --- a/net/netfilter/nft_meta.c +++ b/net/netfilter/nft_meta.c @@ -45,16 +45,15 @@ void nft_meta_get_eval(const struct nft_expr *expr, *dest = skb->len; break; case NFT_META_PROTOCOL: - *dest = 0; - *(__be16 *)dest = skb->protocol; + nft_reg_store16(dest, (__force u16)skb->protocol); break; case NFT_META_NFPROTO: - *dest = pkt->pf; + nft_reg_store8(dest, pkt->pf); break; case NFT_META_L4PROTO: if (!pkt->tprot_set) goto err; - *dest = pkt->tprot; + nft_reg_store8(dest, pkt->tprot); break; case NFT_META_PRIORITY: *dest = skb->priority; @@ -85,14 +84,12 @@ void nft_meta_get_eval(const struct nft_expr *expr, case NFT_META_IIFTYPE: if (in == NULL) goto err; - *dest = 0; - *(u16 *)dest = in->type; + nft_reg_store16(dest, in->type); break; case NFT_META_OIFTYPE: if (out == NULL) goto err; - *dest = 0; - *(u16 *)dest = out->type; + nft_reg_store16(dest, out->type); break; case NFT_META_SKUID: sk = skb_to_full_sk(skb); @@ -142,22 +139,22 @@ void nft_meta_get_eval(const struct nft_expr *expr, #endif case NFT_META_PKTTYPE: if (skb->pkt_type != PACKET_LOOPBACK) { - *dest = skb->pkt_type; + nft_reg_store8(dest, skb->pkt_type); break; } switch (pkt->pf) { case NFPROTO_IPV4: if (ipv4_is_multicast(ip_hdr(skb)->daddr)) - *dest = PACKET_MULTICAST; + nft_reg_store8(dest, PACKET_MULTICAST); else - *dest = PACKET_BROADCAST; + nft_reg_store8(dest, PACKET_BROADCAST); break; case NFPROTO_IPV6: if (ipv6_hdr(skb)->daddr.s6_addr[0] == 0xFF) - *dest = PACKET_MULTICAST; + nft_reg_store8(dest, PACKET_MULTICAST); else - *dest = PACKET_BROADCAST; + nft_reg_store8(dest, PACKET_BROADCAST); break; case NFPROTO_NETDEV: switch (skb->protocol) { @@ -171,14 +168,14 @@ void nft_meta_get_eval(const struct nft_expr *expr, goto err; if (ipv4_is_multicast(iph->daddr)) - *dest = PACKET_MULTICAST; + nft_reg_store8(dest, PACKET_MULTICAST); else - *dest = PACKET_BROADCAST; + nft_reg_store8(dest, PACKET_BROADCAST); break; } case htons(ETH_P_IPV6): - *dest = PACKET_MULTICAST; + nft_reg_store8(dest, PACKET_MULTICAST); break; default: WARN_ON_ONCE(1); @@ -233,7 +230,9 @@ void nft_meta_set_eval(const struct nft_expr *expr, { const struct nft_meta *meta = nft_expr_priv(expr); struct sk_buff *skb = pkt->skb; - u32 value = regs->data[meta->sreg]; + u32 *sreg = ®s->data[meta->sreg]; + u32 value = *sreg; + u8 pkt_type; switch (meta->key) { case NFT_META_MARK: @@ -243,9 +242,12 @@ void nft_meta_set_eval(const struct nft_expr *expr, skb->priority = value; break; case NFT_META_PKTTYPE: - if (skb->pkt_type != value && - skb_pkt_type_ok(value) && skb_pkt_type_ok(skb->pkt_type)) - skb->pkt_type = value; + pkt_type = nft_reg_load8(sreg); + + if (skb->pkt_type != pkt_type && + skb_pkt_type_ok(pkt_type) && + skb_pkt_type_ok(skb->pkt_type)) + skb->pkt_type = pkt_type; break; case NFT_META_NFTRACE: skb->nf_trace = !!value; -- cgit v1.2.3