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 8EC613D8900; Mon, 17 Aug 2026 13:51:46 +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=1786974709; cv=none; b=hRIH5azVLKGrKfRixM+icmzDKnE+WE0t8vJIvUr7QRrtkXxsGZJ2xedDOE6XDOSenU1ynsYTML4oAuiPzOfKqHJ16/sO4294NsR+lFzU2g6gdt958EffKh4OBY5ClFFAGFNqa5mxvHlecMbMkOhvLG0vuskGTMqWiPzWx0UwuNs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786974709; c=relaxed/simple; bh=bxGx4kp5vzbZyH1ZB3fmEDdZnScMblU3WmLaeH1zlmA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=U6XFpea7ORQZEt5ZS+F9n7/dbUYcwbraQh7+GYijTm76mn3nYbkwY6hdY3JqUPFg1KMtgym8ne9PWHy4B0yrv3FPAHqnHGaVTy3bhxIsG0z+GjNFwashh1Js7PnSLlNSb0WGi6KaNTRR3AIpETwbweuDVuMofxOXOxaBiuY3iY0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=M4lvw0aD; 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="M4lvw0aD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D81B1F000E9; Mon, 17 Aug 2026 13:51:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786974704; bh=V5jhXwJEWqXQ7m3D9KrheBy2hb6YP6RnXnZd39g4+eQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=M4lvw0aD33mgLacYlep1Qo1ijPXh5pdd/CWjGswu8sNc9Y+2bhwL1aXh18P0K8u5u dXhSk7Et4hXjOk5cpN86bjoMAIDzBfK85QwhtraXi68qOwFULBYnb09+9+CCZ3ZRkf gPgHULtXkqdEQQ73rzy5WwUeOTKns+bFE/+njlkc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Antonio Quartulli , Sasha Levin Subject: [PATCH 6.18 025/250] ovpn: zero-initialize sockaddr before learning a floated endpoint Date: Mon, 17 Aug 2026 15:29:46 +0200 Message-ID: <20260817132537.487508472@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132536.466235697@linuxfoundation.org> References: <20260817132536.466235697@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: Antonio Quartulli [ Upstream commit 3f012bdbabe211ccbc0c50ea5a1dbc60f8af1532 ] ovpn_peer_endpoints_update() builds the new remote endpoint in an on-stack struct sockaddr_storage that is left uninitialized. For IPv4 only sin_family/sin_addr/sin_port are written, leaving the 8-byte sin_zero padding as stack garbage (for IPv6, sin6_flowinfo is left uninitialized likewise). ovpn_peer_reset_sockaddr() -> ovpn_bind_from_sockaddr() then memcpy()s sizeof(struct sockaddr_in)/sizeof(struct sockaddr_in6) bytes - padding included - into bind->remote. That buffer is later hashed with jhash() over the same length to place the peer in the by_transp_addr table, so the garbage padding lands the floated peer in an essentially random bucket. Lockless lookups in ovpn_peer_get_by_transp_addr() build their key from a zero-initialized sockaddr_storage, compute a different bucket and fail to find the peer. This is also a plain use of uninitialized stack memory in jhash(). Build the floated endpoint with a designated initializer so the padding (sin_zero for IPv4, sin6_flowinfo for IPv6) is zeroed as part of the assignment. This keeps the padding out of the by_transp_addr hash key without memset-ing the whole sockaddr_storage on every received packet. Fixes: f0281c1d3732 ("ovpn: add support for updating local or remote UDP endpoint") Signed-off-by: Antonio Quartulli Signed-off-by: Sasha Levin --- drivers/net/ovpn/peer.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/drivers/net/ovpn/peer.c b/drivers/net/ovpn/peer.c index f502f9c576f8f..3824ee1c2e40a 100644 --- a/drivers/net/ovpn/peer.c +++ b/drivers/net/ovpn/peer.c @@ -218,9 +218,16 @@ void ovpn_peer_endpoints_update(struct ovpn_peer *peer, struct sk_buff *skb) */ local_ip = &ip_hdr(skb)->daddr; sa = (struct sockaddr_in *)&ss; - sa->sin_family = AF_INET; - sa->sin_addr.s_addr = ip_hdr(skb)->saddr; - sa->sin_port = udp_hdr(skb)->source; + /* use a designated initializer so the sin_zero padding + * is zeroed (it ends up in the by_transp_addr hash key) + * without memset-ing the whole sockaddr_storage on the + * RX fast path + */ + *sa = (struct sockaddr_in) { + .sin_family = AF_INET, + .sin_addr.s_addr = ip_hdr(skb)->saddr, + .sin_port = udp_hdr(skb)->source, + }; salen = sizeof(*sa); reset_cache = true; break; @@ -246,11 +253,19 @@ void ovpn_peer_endpoints_update(struct ovpn_peer *peer, struct sk_buff *skb) */ local_ip = &ipv6_hdr(skb)->daddr; sa6 = (struct sockaddr_in6 *)&ss; - sa6->sin6_family = AF_INET6; - sa6->sin6_addr = ipv6_hdr(skb)->saddr; - sa6->sin6_port = udp_hdr(skb)->source; - sa6->sin6_scope_id = ipv6_iface_scope_id(&ipv6_hdr(skb)->saddr, - skb->skb_iif); + /* use a designated initializer so the sin6_flowinfo + * padding is zeroed (it ends up in the by_transp_addr + * hash key) without memset-ing the whole + * sockaddr_storage on the RX fast path + */ + *sa6 = (struct sockaddr_in6) { + .sin6_family = AF_INET6, + .sin6_addr = ipv6_hdr(skb)->saddr, + .sin6_port = udp_hdr(skb)->source, + .sin6_scope_id = + ipv6_iface_scope_id(&ipv6_hdr(skb)->saddr, + skb->skb_iif), + }; salen = sizeof(*sa6); reset_cache = true; break; -- 2.53.0