diff options
author | Liping Zhang <zlpnobody@gmail.com> | 2017-03-08 22:54:18 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-20 10:18:34 +0100 |
commit | 1894d7cb6997c906ec3108e49944e35b084141fa (patch) | |
tree | 02788d11839c460f55b0ac4060b4820611b07b5e /net/ipv4/netfilter | |
parent | 4b42bdfa8bd2797605136bf83569c46a4f98c2c2 (diff) | |
download | linux-rt-1894d7cb6997c906ec3108e49944e35b084141fa.tar.gz |
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 <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4/netfilter')
-rw-r--r-- | net/ipv4/netfilter/nft_masq_ipv4.c | 8 | ||||
-rw-r--r-- | net/ipv4/netfilter/nft_redir_ipv4.c | 8 |
2 files changed, 8 insertions, 8 deletions
diff --git a/net/ipv4/netfilter/nft_masq_ipv4.c b/net/ipv4/netfilter/nft_masq_ipv4.c index 51ced81b616c..dc3628a396ec 100644 --- a/net/ipv4/netfilter/nft_masq_ipv4.c +++ b/net/ipv4/netfilter/nft_masq_ipv4.c @@ -26,10 +26,10 @@ static void nft_masq_ipv4_eval(const struct nft_expr *expr, memset(&range, 0, sizeof(range)); range.flags = priv->flags; if (priv->sreg_proto_min) { - range.min_proto.all = - *(__be16 *)®s->data[priv->sreg_proto_min]; - range.max_proto.all = - *(__be16 *)®s->data[priv->sreg_proto_max]; + range.min_proto.all = (__force __be16)nft_reg_load16( + ®s->data[priv->sreg_proto_min]); + range.max_proto.all = (__force __be16)nft_reg_load16( + ®s->data[priv->sreg_proto_max]); } regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb, pkt->hook, &range, pkt->out); diff --git a/net/ipv4/netfilter/nft_redir_ipv4.c b/net/ipv4/netfilter/nft_redir_ipv4.c index c09d4381427e..f760524e1353 100644 --- a/net/ipv4/netfilter/nft_redir_ipv4.c +++ b/net/ipv4/netfilter/nft_redir_ipv4.c @@ -26,10 +26,10 @@ static void nft_redir_ipv4_eval(const struct nft_expr *expr, memset(&mr, 0, sizeof(mr)); if (priv->sreg_proto_min) { - mr.range[0].min.all = - *(__be16 *)®s->data[priv->sreg_proto_min]; - mr.range[0].max.all = - *(__be16 *)®s->data[priv->sreg_proto_max]; + mr.range[0].min.all = (__force __be16)nft_reg_load16( + ®s->data[priv->sreg_proto_min]); + mr.range[0].max.all = (__force __be16)nft_reg_load16( + ®s->data[priv->sreg_proto_max]); mr.range[0].flags |= NF_NAT_RANGE_PROTO_SPECIFIED; } |