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 5E94115FA6C; Mon, 27 May 2024 14:19:24 +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=1716819564; cv=none; b=basrUdTQhcFA2ZM6BIJCYSU7K43gQn/685Bz3Ul6tMEruEC/axaVRosC8sJy8AcvveRPbDNTrlMaKAh08CplECivrFhYC/xfuzE4A0eT9vddMWhkLu7q9Rcrp2gp8G9J2kD84hhJl5hgd/khucg/2Fpt49tBBx5tFUtemFtU4jk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716819564; c=relaxed/simple; bh=Z2Lu6fp7hgS+t8UgQUG2yU3FkRiF5IM8aE8wjUPcwZ0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LkOmnffcMQtwpa9u9E+AGA2r/b/NQq2ZsWcpcc742wJg38Vw2h156QfhjYSj3/pnW85IgRf9SoXELJql237Isy8Qnd75dOvajexcx3c9BFNukPZi2kOWlqE+/LpQSy/F52ykVo0hnDRQBHSmfXJMcA0i3OjFjQKpzgHNIurSUB0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C2Lh37GA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="C2Lh37GA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EF0BC32781; Mon, 27 May 2024 14:19:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716819563; bh=Z2Lu6fp7hgS+t8UgQUG2yU3FkRiF5IM8aE8wjUPcwZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C2Lh37GAeVQg5A0qg19GVfleMzdSkEsmV1FQtX7c8lTemcwwwCFyhMT9xgA0IizZX uJoesFPPf6joaMYRAwX1dmmmrM3DHPla8tFuBs8/nKvqkeWgxiVoMXTJpmLQyOZOLi CI09ddBKjlcjkHZ932r9r0KeCZaZFx18TXOzkwswdDYNHwBl6L1sluwc1dGSSVZAdv o01G6MC4kQ0iYQ995xThGOLOT/sGwi/fMnjpHCVoRS8ovZ0essHjQ8+D1ILP95JSqf 4v7t/S29uaRRV2po8CwNK2M2oiFcpu6K73ivQVpD8k7NrIlO7bPEdUQ+bArzx2OKg4 icO1Xdl8TqTXw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , syzbot , Kees Cook , Willem de Bruijn , Willem de Bruijn , "David S . Miller" , Sasha Levin , kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 05/13] af_packet: avoid a false positive warning in packet_setsockopt() Date: Mon, 27 May 2024 10:18:42 -0400 Message-ID: <20240527141901.3854691-5-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240527141901.3854691-1-sashal@kernel.org> References: <20240527141901.3854691-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.218 Content-Transfer-Encoding: 8bit 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 db5d16c5d5b11..3ae11961c9cc3 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3762,28 +3762,30 @@ 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