[BRIDGE]: Unaligned access when comparing ethernet addresses (19bb3506) · Commits · 戴 / test

compare_ether_addr() implicitly requires that the addresses passed are 2-bytes aligned in memory. This is not true for br_stp_change_bridge_id() and br_stp_recalculate_bridge_id() in which one of the addresses is unsigned char *, and thus may not be 2-bytes aligned. Signed-off-by:

Evgeny Kravtsunov <emkravts@openvz.org> Signed-off-by:

Kirill Korotaev <dev@openvz.org> Signed-off-by:

Pavel Emelianov <xemul@openvz.org>

net/bridge/br_stp_if.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -126,7 +126,9 @@ void br_stp_disable_port(struct net_bridge_port *p)
		/* called under bridge lock */
		void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
		{
		unsigned char oldaddr[6];
		/* should be aligned on 2 bytes for compare_ether_addr() */
		unsigned short oldaddr_aligned[ETH_ALEN >> 1];
		unsigned char oldaddr = (unsigned char )oldaddr_aligned;
		struct net_bridge_port *p;
		int wasroot;

		@@ -151,11 +153,14 @@ void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
		br_become_root_bridge(br);
		}

		static const unsigned char br_mac_zero[6];
		/* should be aligned on 2 bytes for compare_ether_addr() */
		static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];

		/* called under bridge lock */
		void br_stp_recalculate_bridge_id(struct net_bridge *br)
		{
		const unsigned char *br_mac_zero =
		(const unsigned char *)br_mac_zero_aligned;
		const unsigned char *addr = br_mac_zero;
		struct net_bridge_port *p;

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