From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 41E4513C8F4; Wed, 3 Jul 2024 11:21:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720005677; cv=none; b=IeNn9rNER9RWf0ejp+ZbGnhiCI7NdznUwJOD3tlqRzgsrZV19nHxNpfJ8iGyHVxQFVVW/sYy3/48tWtNi8IelFYmAfs9ArnncqMiHOSw+hk3WkK61IYKXnpf4h9hod+jmf18lOPCjgAqkRUzD3Xf1D5s1WYtzww8rIMhWkJY9O4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720005677; c=relaxed/simple; bh=jRsJ+B6QECw2JZJTcjedl8tY/g4TrkiZvMrWDr2CaBU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mFhzAxQv6tYkBFjOZfFcmnUE5RwkbTCsZNwqiFqX5da2u1fysSDil4ofFrPAoSNsvUu0wmBNMtRk9ig55A8KIgGvPMS6/VJAY9pxQ7SbBAXmizeBXDo0dNBAwi5tvS+HEWDudpoH4QVuqnl/ykzw6a7ekVS18Gp0USfA8KKzvYo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=p6O2TL8I; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="p6O2TL8I" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD7A6C2BD10; Wed, 3 Jul 2024 11:21:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720005677; bh=jRsJ+B6QECw2JZJTcjedl8tY/g4TrkiZvMrWDr2CaBU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p6O2TL8I/zM+eSHNAmZ0G25nehQVlWixr9NvY2rEmbQ3o5J+mCYXgQ8Eiw224qcp1 LDDgkgDNRZ9t6+MZj4PdEDNXGjmYSGIJhKpr30jPTQ9jYbjWW0LbQ6wVTGAWY3ivEK 6bZjQESThp2+ssbQDpV6cjeGg0JqaDKE/tjTaEr4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot , Eric Dumazet , Kees Cook , Willem de Bruijn , Willem de Bruijn , "David S. Miller" , Sasha Levin Subject: [PATCH 5.15 160/356] af_packet: avoid a false positive warning in packet_setsockopt() Date: Wed, 3 Jul 2024 12:38:16 +0200 Message-ID: <20240703102919.157923358@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102913.093882413@linuxfoundation.org> References: <20240703102913.093882413@linuxfoundation.org> User-Agent: quilt/0.67 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 [ Upstream commit 86d43e2bf93ccac88ef71cee36a23282ebd9e427 ] Although the code is correct, the following line copy_from_sockptr(&req_u.req, optval, len)); triggers this warning : memcpy: detected field-spanning write (size 28) of single field "dst" at include/linux/sockptr.h:49 (size 16) Refactor the code to be more explicit. Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: Kees Cook Cc: Willem de Bruijn Reviewed-by: Kees Cook Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 4f920502f92fe..8d0feb9ad5a52 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3757,28 +3757,30 @@ packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, case PACKET_TX_RING: { union tpacket_req_u req_u; - int len; + ret = -EINVAL; lock_sock(sk); switch (po->tp_version) { case TPACKET_V1: case TPACKET_V2: - len = sizeof(req_u.req); + if (optlen < sizeof(req_u.req)) + break; + ret = copy_from_sockptr(&req_u.req, optval, + sizeof(req_u.req)) ? + -EINVAL : 0; break; case TPACKET_V3: default: - len = sizeof(req_u.req3); + if (optlen < sizeof(req_u.req3)) + break; + ret = copy_from_sockptr(&req_u.req3, optval, + sizeof(req_u.req3)) ? + -EINVAL : 0; break; } - if (optlen < len) { - ret = -EINVAL; - } else { - if (copy_from_sockptr(&req_u.req, optval, len)) - ret = -EFAULT; - else - ret = packet_set_ring(sk, &req_u, 0, - optname == PACKET_TX_RING); - } + if (!ret) + ret = packet_set_ring(sk, &req_u, 0, + optname == PACKET_TX_RING); release_sock(sk); return ret; } -- 2.43.0