From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 146C33CB2EA; Tue, 13 Oct 2026 12:19:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791893970; cv=none; b=hVw32w6K1fWWmnLosMff9gXwxaZELPpyAndATt3ek/5Fn0zdEoyjs3Z10g6C8bfKcGCpOu0GCTL7iLfYhgJxG4YLt4kdGaS6S0YxxF0rriyWnTQg4s3cwLpM3j2kPl+QLnjktfZPd7ze4hjWFPn9OL3JIdns3/Tqfq+xzXiqdnw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791893970; c=relaxed/simple; bh=ryeqykVPIjDdnA4BRhNqX+caXwLNQIx9+m2BpkBnJdI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nOu+x2OlXUnvdFuZMWpNPAGKPB+HV4RYMwB8wMZU/iEAxZ80dQlOq/VMGwAv3fxzZjD0+HGXKywuxB56wBDLjzQHtBkaBdrxEXLpviXOUgEjr8PCJJazzgXLYClI48VPuuFBFyCXQAtZT6fhKndM1zD/PX1yajB/hn48NF6Js5Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XRX3f83c; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XRX3f83c" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 032421F000FF; Tue, 13 Oct 2026 12:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791893968; bh=CSQdeDY+16W4nGylI6xNRmoeLlNHI9s4RN7dj72t36k=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XRX3f83cJHaZcncMrKhC98znOTqbxVk3vP0UDHPbK1d4yaXuH2WwCdyDx/iHiZVWR CU5MijiVyfmnqZPHP+ZKgKfvqDubj8bS9yuvQZyh89t7J/52GYQEMwWnRvsX64NuZr RRCg15DjzqW/Cnu96rZdhO2O+70EiZWhlF+CD3Lk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nikolay Aleksandrov , Petr Machata , Ido Schimmel , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 404/621] net: bridge: arp/nd proxy: fix reading neigh ha Date: Tue, 13 Oct 2026 13:36:39 +0200 Message-ID: <20261013112930.428076795@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112920.855194808@linuxfoundation.org> References: <20261013112920.855194808@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikolay Aleksandrov [ Upstream commit 57549ab9079122991dfa0f8248ca00e101e8e69b ] Currently neigh ha address is read directly, but that can result in torn/partial reads if the neigh is being updated. Use neigh_ha_snapshot to take a stable snapshot of the address. Fixes: 057658cb33fb ("bridge: suppress arp pkts on BR_NEIGH_SUPPRESS ports") Fixes: ed842faeb2bd ("bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports") Signed-off-by: Nikolay Aleksandrov Reviewed-by: Petr Machata Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260818150756.890025-2-razor@blackwall.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/bridge/br_arp_nd_proxy.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c index 4cd3470e5f56c..3203706d02b88 100644 --- a/net/bridge/br_arp_nd_proxy.c +++ b/net/bridge/br_arp_nd_proxy.c @@ -194,13 +194,15 @@ void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br, n = neigh_lookup(&arp_tbl, &tip, vlandev); if (n) { struct net_bridge_fdb_entry *f; + u8 ha[ETH_ALEN] __aligned(2); if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { neigh_release(n); return; } - f = br_fdb_find_rcu(br, n->ha, vid); + neigh_ha_snapshot(ha, n, n->dev); + f = br_fdb_find_rcu(br, ha, vid); if (f) { const struct net_bridge_port *dst = READ_ONCE(f->dst); bool replied = false; @@ -210,10 +212,10 @@ void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br, br_is_neigh_suppress_enabled(dst, vid)) { if (!vid) br_arp_send(br, p, skb->dev, sip, tip, - sha, n->ha, sha, 0, 0); + sha, ha, sha, 0, 0); else br_arp_send(br, p, skb->dev, sip, tip, - sha, n->ha, sha, + sha, ha, sha, skb->vlan_proto, skb_vlan_tag_get(skb)); replied = true; @@ -251,7 +253,7 @@ struct nd_msg *br_is_nd_neigh_msg(const struct sk_buff *skb, struct nd_msg *msg) } static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p, - struct sk_buff *request, struct neighbour *n, + struct sk_buff *request, struct neighbour *n, u8 *ha, __be16 vlan_proto, u16 vlan_tci) { struct net_device *dev = request->dev; @@ -309,7 +311,7 @@ static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p, ipv6_eth_mc_map(&in6addr_linklocal_allnodes, eth_hdr(reply)->h_dest); else ether_addr_copy(eth_hdr(reply)->h_dest, daddr); - ether_addr_copy(eth_hdr(reply)->h_source, n->ha); + ether_addr_copy(eth_hdr(reply)->h_source, ha); eth_hdr(reply)->h_proto = htons(ETH_P_IPV6); reply->protocol = htons(ETH_P_IPV6); @@ -339,7 +341,7 @@ static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p, na->icmph.icmp6_override = 1; na->icmph.icmp6_solicited = dad ? 0 : 1; na->target = ns->target; - ether_addr_copy(&na->opt[2], n->ha); + ether_addr_copy(&na->opt[2], ha); na->opt[0] = ND_OPT_TARGET_LL_ADDR; na->opt[1] = na_olen >> 3; @@ -368,7 +370,7 @@ static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p, __vlan_hwaccel_put_tag(reply, vlan_proto, vlan_tci); netdev_dbg(dev, "nd send dev %s dst %pI6 dst_hw %pM src %pI6 src_hw %pM\n", - dev->name, &pip6->daddr, daddr, &pip6->saddr, n->ha); + dev->name, &pip6->daddr, daddr, &pip6->saddr, ha); if (p) { dev_queue_xmit(reply); @@ -469,24 +471,26 @@ void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br, n = neigh_lookup(ipv6_stub->nd_tbl, &msg->target, vlandev); if (n) { struct net_bridge_fdb_entry *f; + u8 ha[ETH_ALEN] __aligned(2); if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { neigh_release(n); return; } - f = br_fdb_find_rcu(br, n->ha, vid); + neigh_ha_snapshot(ha, n, n->dev); + f = br_fdb_find_rcu(br, ha, vid); if (f) { const struct net_bridge_port *dst = READ_ONCE(f->dst); bool replied = false; if (br_is_neigh_suppress_enabled(dst, vid)) { if (vid != 0) - br_nd_send(br, p, skb, n, + br_nd_send(br, p, skb, n, ha, skb->vlan_proto, skb_vlan_tag_get(skb)); else - br_nd_send(br, p, skb, n, 0, 0); + br_nd_send(br, p, skb, n, ha, 0, 0); replied = true; } -- 2.53.0