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 05972331A61; Fri, 7 Aug 2026 15:22:47 +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=1786116168; cv=none; b=nx48tb43JPGZ+wa3EW9atPEUHbO8vAo6iOnKbHIVT+Ny73bO9sePCQRRF76yvBeHgUjLY56+lvPgfNU8PgEW0FXZ5pSD19AIUPamP/8BGJLL19qR+cGZIffEBKw1ey0J3w5WiVpNwrQfXcJ04EEQot0xLwKnE8pc7wKjw5W482s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786116168; c=relaxed/simple; bh=fWosWX4GcuN0JP5QNxNLHAv21ZgOIzAPtsWFvkIJMSc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aHCt8E1O/ZMW4sHfG199HR/zhJjIs7QM8IhqXU78UtaSSEPlUMXPOVqlNZOx5AaY8gidGC14+TDjqkKGrwrKyhnZozR0HROX4Fp1I8cmBsufrt+HD5NWPHdiMLl6HKJpLyjPJo61chcglQQidYtagYy3+FQU2WDH1qfvQa0cbHU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cxXjFsah; 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="cxXjFsah" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 610CC1F000E9; Fri, 7 Aug 2026 15:22:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786116166; bh=ZYySzm5r+EG1ExqCqPVBneUqQnBAxUXYyC+CcF1b6fo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cxXjFsahFK4UulvtJfK6niPOwShd4+z/jwe+ZKNApeitWwGqCKeL6Wxh1w0tT+cBQ moaFYuw7FU67540QBjNk/KPxYvG5tRPDlXOl4n3gs4gPxrm+8aKe/8S4BcXy17CJWo sBEzQvuhs8PLtUsck2hWMtO5P8/HAszRfTeWjd7Q= 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 6.6 136/261] vxlan: use neigh_ha_snapshot() in route_shortcircuit() Date: Fri, 7 Aug 2026 16:38:13 +0200 Message-ID: <20260807143418.299830256@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143415.358597922@linuxfoundation.org> References: <20260807143415.358597922@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 6.6-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 @@ -2159,9 +2159,11 @@ 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); @@ -2169,7 +2171,7 @@ 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;