From 246de0b48bc2d962f2399398df2e71cab68e8d95 Mon Sep 17 00:00:00 2001 From: jow Date: Fri, 6 Dec 2013 15:42:35 +0000 Subject: [PATCH] generic: workaround arptables arpt_arp structure padding issue (#14577) Linaro GCC 4.6-2013.05 incorrectly pads the arpt_arp structure on at least the ar71xx target, resulting in a two bytes shorter struct in the kernel compared to what arptables userspace expects. When comparing sizeof(struct arpt_arp) in kernel and userspace, the former yields 162 byte, while the latter is 164 byte. As a consequence, the subsequent target_offset and next_offset members of the parent arpt_entry structure contain invalid values when processed by the arptables binary, leading to bad memory accesses in the populate_cache() procedure, subsequently causing a segfault. Signed-off-by: Jo-Philipp Wich git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38999 3c298f89-4303-0410-b956-a3cf2f4a3e73 --- .../614-netfilter_arpt_arp_padding_fix.patch | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) create mode 100644 target/linux/generic/patches-3.10/614-netfilter_arpt_arp_padding_fix.patch diff --git a/target/linux/generic/patches-3.10/614-netfilter_arpt_arp_padding_fix.patch b/target/linux/generic/patches-3.10/614-netfilter_arpt_arp_padding_fix.patch new file mode 100644 index 0000000000..70a8d04fa2 --- /dev/null +++ b/target/linux/generic/patches-3.10/614-netfilter_arpt_arp_padding_fix.patch @@ -0,0 +1,16 @@ +--- a/include/uapi/linux/netfilter_arp/arp_tables.h ++++ b/include/uapi/linux/netfilter_arp/arp_tables.h +@@ -68,6 +68,13 @@ struct arpt_arp { + __u8 flags; + /* Inverse flags */ + __u16 invflags; ++ ++ /* For some reason Linaro GCC 4.6-2013.05 omits the two ++ * byte padding here when building for MIPS 34kc, leading to ++ * userspace abi mismatches. ++ * Add a dummy field to align this struct to 4 bytes ++ */ ++ __u16 padding; + }; + + /* Values for "flag" field in struct arpt_ip (general arp structure). -- 2.11.0