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 73FDD354AE3; Fri, 7 Aug 2026 15:45:12 +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=1786117513; cv=none; b=CZxeO1/UVcoaKUpRzgwAhBZRF67hXStCVXbGy0IWzeA9MLpWHJ7NRCx5BBMFFjvOv93Ha3Fv5fTRAeiZ4umlvhU54NYmaPHHCZXsq+0fzh5It3bEAqDV4+zxp/8p2ql+vROwjTcUs/h94VSoYsUSRATXqZCFkQslcaLz0jjcjjw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786117513; c=relaxed/simple; bh=8wSgA6JKhdFrr9yYOxYxfCC2+lhgEB85ftgwMm4sekw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BRHIk7ac0BAb2GAR6rJG+mb4HkakbK9/T9ROPxr1Sj9xtiYzO0GqURNOuSFx58n1TssD22dJRm9IiChIvDqI4I3eUZxRawRExNrXsNYHdbKX4Fd2ech+cywIg0D5lqxFg7MSYrkcQ55FEpf0txrOABdJVb1qsmYAKDxh0WMa0w4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cLw4NDih; 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="cLw4NDih" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C89981F000E9; Fri, 7 Aug 2026 15:45:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786117512; bh=d/x12fezSijydpEtfaSLQHmaN28OqzAFhVUZxyGIhCI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cLw4NDih62kxWpCVGt7yEgC+FBDidE2m+GcD0w4irGplicSklN55uBKRu6rdVlbH3 yMn+1rWDkUotcI03TO4V1+POIdw46cYhLNayj+ltFhF/eubvvBMfAZabHEr+4kSdvY b0XI1Coar9rgOhzscn5KDJdygR28/sDjygr3jBRA= 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 7.1 308/438] vxlan: use neigh_ha_snapshot() in route_shortcircuit() Date: Fri, 7 Aug 2026 16:38:24 +0200 Message-ID: <20260807143434.538099866@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143428.008222056@linuxfoundation.org> References: <20260807143428.008222056@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 7.1-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 @@ -2160,9 +2160,11 @@ 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); @@ -2170,7 +2172,7 @@ 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;