From 89a26cd4b501e9511d3cd3d22327fc76a75a38b3 Mon Sep 17 00:00:00 2001
From: Juliana Rodrigueiro <juliana.rodrigueiro@intra2net.com>
Date: Fri, 16 Aug 2019 17:02:22 +0200
Subject: netfilter: xt_nfacct: Fix alignment mismatch in xt_nfacct_match_info
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>
---
include/uapi/linux/netfilter/xt_nfacct.h | 5 +++++
1 file changed, 5 insertions(+)
(limited to 'include/uapi')
diff --git a/include/uapi/linux/netfilter/xt_nfacct.h b/include/uapi/linux/netfilter/xt_nfacct.h
index 5c8a4d760ee3..b5123ab8d54a 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 */
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