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| author | Stephen Suryaputra <ssuryaextr@gmail.com> | 2020-08-04 17:44:09 -0400 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2020-08-10 13:02:43 +0200 |
| commit | b428336676dbca363262cc134b6218205df4f530 (patch) | |
| tree | d076b09df1ca64787fee763874a2b9657c7704ca /net/netfilter | |
| parent | 7c7ab580db49cc7befe5f4b91bb1920cd6b07575 (diff) | |
| download | linux-b428336676dbca363262cc134b6218205df4f530.tar.gz linux-b428336676dbca363262cc134b6218205df4f530.tar.bz2 linux-b428336676dbca363262cc134b6218205df4f530.zip | |
netfilter: nf_tables: nft_exthdr: the presence return value should be little-endian
On big-endian machine, the returned register data when the exthdr is
present is not being compared correctly because little-endian is
assumed. The function nft_cmp_fast_mask(), called by nft_cmp_fast_eval()
and nft_cmp_fast_init(), calls cpu_to_le32().
The following dump also shows that little endian is assumed:
$ nft --debug=netlink add rule ip recordroute forward ip option rr exists counter
ip
[ exthdr load ipv4 1b @ 7 + 0 present => reg 1 ]
[ cmp eq reg 1 0x01000000 ]
[ counter pkts 0 bytes 0 ]
Lastly, debug print in nft_cmp_fast_init() and nft_cmp_fast_eval() when
RR option exists in the packet shows that the comparison fails because
the assumption:
nft_cmp_fast_init:189 priv->sreg=4 desc.len=8 mask=0xff000000 data.data[0]=0x10003e0
nft_cmp_fast_eval:57 regs->data[priv->sreg=4]=0x1 mask=0xff000000 priv->data=0x1000000
v2: use nft_reg_store8() instead (Florian Westphal). Also to avoid the
warnings reported by kernel test robot.
Fixes: dbb5281a1f84 ("netfilter: nf_tables: add support for matching IPv4 options")
Fixes: c078ca3b0c5b ("netfilter: nft_exthdr: Add support for existence check")
Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/nft_exthdr.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c index 07782836fad6..3c48cdc8935d 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -44,7 +44,7 @@ static void nft_exthdr_ipv6_eval(const struct nft_expr *expr, err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL); if (priv->flags & NFT_EXTHDR_F_PRESENT) { - *dest = (err >= 0); + nft_reg_store8(dest, err >= 0); return; } else if (err < 0) { goto err; @@ -141,7 +141,7 @@ static void nft_exthdr_ipv4_eval(const struct nft_expr *expr, err = ipv4_find_option(nft_net(pkt), skb, &offset, priv->type); if (priv->flags & NFT_EXTHDR_F_PRESENT) { - *dest = (err >= 0); + nft_reg_store8(dest, err >= 0); return; } else if (err < 0) { goto err; |