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 C133815AE3 for ; Wed, 9 Aug 2023 10:47:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 445CFC433C9; Wed, 9 Aug 2023 10:47:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691578029; bh=jH3OKRli/CgO/QzwDV3ipOTPryXXWEjh7CldkaRqK2o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U9n9zpdnrawq1c+0bMwerTcJO9WjgtED2rZgQ5DmfsKlmxfiUZvBj+yx9/K7xoWgn tjb0wsTLWthyGMRnRJgCnrIM4gKt3CWJAFHwnMS66liGN1Y1qfgjosGHkczwo2ALB8 utRgumT1l9XfuV0in5i7lJykxAm1hZykoTw/mJVA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lin Ma , Simon Horman , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.4 081/165] net: dcb: choose correct policy to parse DCB_ATTR_BCN Date: Wed, 9 Aug 2023 12:40:12 +0200 Message-ID: <20230809103645.451346512@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103642.720851262@linuxfoundation.org> References: <20230809103642.720851262@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Lin Ma [ Upstream commit 31d49ba033095f6e8158c60f69714a500922e0c3 ] The dcbnl_bcn_setcfg uses erroneous policy to parse tb[DCB_ATTR_BCN], which is introduced in commit 859ee3c43812 ("DCB: Add support for DCB BCN"). Please see the comment in below code static int dcbnl_bcn_setcfg(...) { ... ret = nla_parse_nested_deprecated(..., dcbnl_pfc_up_nest, .. ) // !!! dcbnl_pfc_up_nest for attributes // DCB_PFC_UP_ATTR_0 to DCB_PFC_UP_ATTR_ALL in enum dcbnl_pfc_up_attrs ... for (i = DCB_BCN_ATTR_RP_0; i <= DCB_BCN_ATTR_RP_7; i++) { // !!! DCB_BCN_ATTR_RP_0 to DCB_BCN_ATTR_RP_7 in enum dcbnl_bcn_attrs ... value_byte = nla_get_u8(data[i]); ... } ... for (i = DCB_BCN_ATTR_BCNA_0; i <= DCB_BCN_ATTR_RI; i++) { // !!! DCB_BCN_ATTR_BCNA_0 to DCB_BCN_ATTR_RI in enum dcbnl_bcn_attrs ... value_int = nla_get_u32(data[i]); ... } ... } That is, the nla_parse_nested_deprecated uses dcbnl_pfc_up_nest attributes to parse nlattr defined in dcbnl_pfc_up_attrs. But the following access code fetch each nlattr as dcbnl_bcn_attrs attributes. By looking up the associated nla_policy for dcbnl_bcn_attrs. We can find the beginning part of these two policies are "same". static const struct nla_policy dcbnl_pfc_up_nest[...] = { [DCB_PFC_UP_ATTR_0] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_1] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_2] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_3] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_4] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_5] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_6] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_7] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_ALL] = {.type = NLA_FLAG}, }; static const struct nla_policy dcbnl_bcn_nest[...] = { [DCB_BCN_ATTR_RP_0] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_1] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_2] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_3] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_4] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_5] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_6] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_7] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_ALL] = {.type = NLA_FLAG}, // from here is somewhat different [DCB_BCN_ATTR_BCNA_0] = {.type = NLA_U32}, ... [DCB_BCN_ATTR_ALL] = {.type = NLA_FLAG}, }; Therefore, the current code is buggy and this nla_parse_nested_deprecated could overflow the dcbnl_pfc_up_nest and use the adjacent nla_policy to parse attributes from DCB_BCN_ATTR_BCNA_0. Hence use the correct policy dcbnl_bcn_nest to parse the nested tb[DCB_ATTR_BCN] TLV. Fixes: 859ee3c43812 ("DCB: Add support for DCB BCN") Signed-off-by: Lin Ma Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230801013248.87240-1-linma@zju.edu.cn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/dcb/dcbnl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c index c0c4381285759..2e6b8c8fd2ded 100644 --- a/net/dcb/dcbnl.c +++ b/net/dcb/dcbnl.c @@ -980,7 +980,7 @@ static int dcbnl_bcn_setcfg(struct net_device *netdev, struct nlmsghdr *nlh, return -EOPNOTSUPP; ret = nla_parse_nested_deprecated(data, DCB_BCN_ATTR_MAX, - tb[DCB_ATTR_BCN], dcbnl_pfc_up_nest, + tb[DCB_ATTR_BCN], dcbnl_bcn_nest, NULL); if (ret) return ret; -- 2.40.1