diff options
| author | Florian Westphal | 2023-12-04 12:29:54 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso | 2023-12-06 17:15:42 +0100 |
| commit | 63331e37fb227e796894b31d713697612c8dee7f (patch) | |
| tree | 6a0f00a90a4c390719a09fba59872a1f22e049fc /net | |
| parent | 317eb9685095678f2c9f5a8189de698c5354316a (diff) | |
netfilter: nf_tables: fix 'exist' matching on bigendian arches
Maze reports "tcp option fastopen exists" fails to match on
OpenWrt 22.03.5, r20134-5f15225c1e (5.10.176) router.
"tcp option fastopen exists" translates to:
inet
[ exthdr load tcpopt 1b @ 34 + 0 present => reg 1 ]
[ cmp eq reg 1 0x00000001 ]
.. but existing nft userspace generates a 1-byte compare.
On LSB (x86), "*reg32 = 1" is identical to nft_reg_store8(reg32, 1), but
not on MSB, which will place the 1 last. IOW, on bigendian aches the cmp8
is awalys false.
Make sure we store this in a consistent fashion, so existing userspace
will also work on MSB (bigendian).
Regardless of this patch we can also change nft userspace to generate
'reg32 == 0' and 'reg32 != 0' instead of u8 == 0 // u8 == 1 when
adding 'option x missing/exists' expressions as well.
Fixes: 3c1fece8819e ("netfilter: nft_exthdr: Allow checking TCP option presence, too")
Fixes: b9f9a485fb0e ("netfilter: nft_exthdr: add boolean DCCP option matching")
Fixes: 055c4b34b94f ("netfilter: nft_fib: Support existence check")
Reported-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Closes: https://lore.kernel.org/netfilter-devel/CAHo-OozyEqHUjL2-ntATzeZOiuftLWZ_HU6TOM_js4qLfDEAJg@mail.gmail.com/
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nft_exthdr.c | 4 | ||||
| -rw-r--r-- | net/netfilter/nft_fib.c | 8 |
2 files changed, 8 insertions, 4 deletions
diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c index 3fbaa7bf41f9..6eb571d0c3fd 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -214,7 +214,7 @@ static void nft_exthdr_tcp_eval(const struct nft_expr *expr, offset = i + priv->offset; if (priv->flags & NFT_EXTHDR_F_PRESENT) { - *dest = 1; + nft_reg_store8(dest, 1); } else { if (priv->len % NFT_REG32_SIZE) dest[priv->len / NFT_REG32_SIZE] = 0; @@ -461,7 +461,7 @@ static void nft_exthdr_dccp_eval(const struct nft_expr *expr, type = bufp[0]; if (type == priv->type) { - *dest = 1; + nft_reg_store8(dest, 1); return; } diff --git a/net/netfilter/nft_fib.c b/net/netfilter/nft_fib.c index 1bfe258018da..37cfe6dd712d 100644 --- a/net/netfilter/nft_fib.c +++ b/net/netfilter/nft_fib.c @@ -145,11 +145,15 @@ void nft_fib_store_result(void *reg, const struct nft_fib *priv, switch (priv->result) { case NFT_FIB_RESULT_OIF: index = dev ? dev->ifindex : 0; - *dreg = (priv->flags & NFTA_FIB_F_PRESENT) ? !!index : index; + if (priv->flags & NFTA_FIB_F_PRESENT) + nft_reg_store8(dreg, !!index); + else + *dreg = index; + break; case NFT_FIB_RESULT_OIFNAME: if (priv->flags & NFTA_FIB_F_PRESENT) - *dreg = !!dev; + nft_reg_store8(dreg, !!dev); else strscpy_pad(reg, dev ? dev->name : "", IFNAMSIZ); break; |