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 BB13C421249; Mon, 17 Aug 2026 14:37:03 +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=1786977424; cv=none; b=GgsFGEfDr/6dY1sYJ4cszbTxMU+4U//tXb5q7q9caSdUnuFhE8q8Owq+amqkvBfohYEhlA1ZkfFb0vVfmWne7dP8A7p8VA5zq7CIjzLpzVY0xKCW1Alq4YTaz5ul+uoP5cid9fYALlT8xUvxf/GA+xCI4zT24JgmlHFzjTZsKmE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786977424; c=relaxed/simple; bh=IKOwVOEMr/kBmcMXgQZmzoSSJkHExIv36cQSkHUFRiI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JIEebFtbQoAcRU3JzpvuXLQx8ec5ET1+kv+t13SjfODe51azqMkFz1p8c01xHYTbSfb5Lc+ork5hWGYat7rIrYyiNwm0eKBnOTt1YzaqfoyNW37Bu1uH0KrnqqBc7G3ZbTkZKZ1cy1uKORyl+DQVGkfFADAe2fJl0QfY5vD00/0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=so5/NThV; 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="so5/NThV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F0F791F000E9; Mon, 17 Aug 2026 14:37:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786977423; bh=XZCT7iN5g7a680IC6lSGMRnXbe3JkvF+8ZhfglQ46PE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=so5/NThVdT66kos9VdBWy1thNqOuDrxyawKR8pel/1trppU4g7OuFfFfceZ1BhG/P EAklMko9FQMRym0gWSa+fMdySg+NMZf243b15KCzPXvlb+10sOClIqi/7dXBTAPLjD d8DWL9gC25kLRr8KiiU8FEdYky7LwyG9P3cChTGA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Vadim Fedorenko , Jakub Kicinski Subject: [PATCH 5.15 325/456] vxlan: use neigh_ha_snapshot() in route_shortcircuit() Date: Mon, 17 Aug 2026 15:31:55 +0200 Message-ID: <20260817132552.379103770@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132539.792407575@linuxfoundation.org> References: <20260817132539.792407575@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d upstream. The neighbour hardware address n->ha can be updated asynchronously by the neighbour subsystem, protected by n->ha_lock seqlock. Reading n->ha without holding the seqlock loop can lead to torn reads or reading a partially updated MAC address. Use neigh_ha_snapshot() in route_shortcircuit() to safely copy n->ha under read_seqbegin()/read_seqretry() lock protection before using it. Note that arp_reduce() and neigh_reduce() seem to have the same issue left for future patches. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet Reviewed-by: Vadim Fedorenko Link: https://patch.msgid.link/20260723144249.759100-4-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/vxlan/vxlan_core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -2288,9 +2288,11 @@ static bool route_shortcircuit(struct ne } if (n) { + u8 haddr[ETH_ALEN]; bool diff; - diff = !ether_addr_equal(eth_hdr(skb)->h_dest, n->ha); + neigh_ha_snapshot(haddr, n, dev); + diff = !ether_addr_equal_unaligned(eth_hdr(skb)->h_dest, haddr); if (diff) { if (skb_cow_head(skb, 0)) { neigh_release(n); @@ -2298,7 +2300,7 @@ static bool route_shortcircuit(struct ne } memcpy(eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, dev->addr_len); - memcpy(eth_hdr(skb)->h_dest, n->ha, dev->addr_len); + memcpy(eth_hdr(skb)->h_dest, haddr, dev->addr_len); } neigh_release(n); return diff;