[PATCH AUTOSEL 4.14 08/36] netfilter: xt_nfacct: Fix alignment mismatch in xt_nfacct_match_info

[PATCH AUTOSEL 4.14 08/36] netfilter: xt_nfacct: Fix alignment mismatch in xt_nfacct_match_info

[Sasha Levin]

From: Juliana Rodrigueiro <juliana.rodrigueiro@intra2net.com>

[ Upstream commit 89a26cd4b501e9511d3cd3d22327fc76a75a38b3 ]

When running a 64-bit kernel with a 32-bit iptables binary, the size of
the xt_nfacct_match_info struct diverges.

    kernel: sizeof(struct xt_nfacct_match_info) : 40
    iptables: sizeof(struct xt_nfacct_match_info)) : 36

Trying to append nfacct related rules results in an unhelpful message.
Although it is suggested to look for more information in dmesg, nothing
can be found there.

    # iptables -A <chain> -m nfacct --nfacct-name <acct-object>
    iptables: Invalid argument. Run `dmesg' for more information.

This patch fixes the memory misalignment by enforcing 8-byte alignment
within the struct's first revision. This solution is often used in many
other uapi netfilter headers.

Signed-off-by: Juliana Rodrigueiro <juliana.rodrigueiro@intra2net.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/uapi/linux/netfilter/xt_nfacct.h |  5 ++++
 net/netfilter/xt_nfacct.c                | 36 ++++++++++++++++--------
 2 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/include/uapi/linux/netfilter/xt_nfacct.h b/include/uapi/linux/netfilter/xt_nfacct.h
index 5c8a4d760ee34..b5123ab8d54a8 100644
--- a/include/uapi/linux/netfilter/xt_nfacct.h
+++ b/include/uapi/linux/netfilter/xt_nfacct.h
@@ -11,4 +11,9 @@ struct xt_nfacct_match_info {
 	struct nf_acct	*nfacct;
 };
 
+struct xt_nfacct_match_info_v1 {
+	char		name[NFACCT_NAME_MAX];
+	struct nf_acct	*nfacct __attribute__((aligned(8)));
+};
+
 #endif /* _XT_NFACCT_MATCH_H */
diff --git a/net/netfilter/xt_nfacct.c b/net/netfilter/xt_nfacct.c
index 6f92d25590a85..ea447b437f122 100644
--- a/net/netfilter/xt_nfacct.c
+++ b/net/netfilter/xt_nfacct.c
@@ -55,25 +55,39 @@ nfacct_mt_destroy(const struct xt_mtdtor_param *par)
 	nfnl_acct_put(info->nfacct);
 }
 
-static struct xt_match nfacct_mt_reg __read_mostly = {
-	.name       = "nfacct",
-	.family     = NFPROTO_UNSPEC,
-	.checkentry = nfacct_mt_checkentry,
-	.match      = nfacct_mt,
-	.destroy    = nfacct_mt_destroy,
-	.matchsize  = sizeof(struct xt_nfacct_match_info),
-	.usersize   = offsetof(struct xt_nfacct_match_info, nfacct),
-	.me         = THIS_MODULE,
+static struct xt_match nfacct_mt_reg[] __read_mostly = {
+	{
+		.name       = "nfacct",
+		.revision   = 0,
+		.family     = NFPROTO_UNSPEC,
+		.checkentry = nfacct_mt_checkentry,
+		.match      = nfacct_mt,
+		.destroy    = nfacct_mt_destroy,
+		.matchsize  = sizeof(struct xt_nfacct_match_info),
+		.usersize   = offsetof(struct xt_nfacct_match_info, nfacct),
+		.me         = THIS_MODULE,
+	},
+	{
+		.name       = "nfacct",
+		.revision   = 1,
+		.family     = NFPROTO_UNSPEC,
+		.checkentry = nfacct_mt_checkentry,
+		.match      = nfacct_mt,
+		.destroy    = nfacct_mt_destroy,
+		.matchsize  = sizeof(struct xt_nfacct_match_info_v1),
+		.usersize   = offsetof(struct xt_nfacct_match_info_v1, nfacct),
+		.me         = THIS_MODULE,
+	},
 };
 
 static int __init nfacct_mt_init(void)
 {
-	return xt_register_match(&nfacct_mt_reg);
+	return xt_register_matches(nfacct_mt_reg, ARRAY_SIZE(nfacct_mt_reg));
 }
 
 static void __exit nfacct_mt_exit(void)
 {
-	xt_unregister_match(&nfacct_mt_reg);
+	xt_unregister_matches(nfacct_mt_reg, ARRAY_SIZE(nfacct_mt_reg));
 }
 
 module_init(nfacct_mt_init);
-- 
2.20.1

[PATCH AUTOSEL 4.14 19/36] netfilter: nf_conntrack_ftp: Fix debug output

[Sasha Levin]

From: Thomas Jarosch <thomas.jarosch@intra2net.com>

[ Upstream commit 3a069024d371125227de3ac8fa74223fcf473520 ]

The find_pattern() debug output was printing the 'skip' character.
This can be a NULL-byte and messes up further pr_debug() output.

Output without the fix:
kernel: nf_conntrack_ftp: Pattern matches!
kernel: nf_conntrack_ftp: Skipped up to `<7>nf_conntrack_ftp: find_pattern `PORT': dlen = 8
kernel: nf_conntrack_ftp: find_pattern `EPRT': dlen = 8

Output with the fix:
kernel: nf_conntrack_ftp: Pattern matches!
kernel: nf_conntrack_ftp: Skipped up to 0x0 delimiter!
kernel: nf_conntrack_ftp: Match succeeded!
kernel: nf_conntrack_ftp: conntrack_ftp: match `172,17,0,100,200,207' (20 bytes at 4150681645)
kernel: nf_conntrack_ftp: find_pattern `PORT': dlen = 8

Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nf_conntrack_ftp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index f0e9a7511e1ac..c236c7d1655d0 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -323,7 +323,7 @@ static int find_pattern(const char *data, size_t dlen,
 		i++;
 	}
 
-	pr_debug("Skipped up to `%c'!\n", skip);
+	pr_debug("Skipped up to 0x%hhx delimiter!\n", skip);
 
 	*numoff = i;
 	*numlen = getnum(data + i, dlen - i, cmd, term, numoff);
-- 
2.20.1