From: Maxime Chevallier Date: Sat, 1 Mar 2025 14:11:13 +0000 (+0100) Subject: net: ethtool: netlink: Allow NULL nlattrs when getting a phy_device X-Git-Tag: v6.14-rc6~26^2~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=637399bf7e77797811adf340090b561a8f9d1213;p=thirdparty%2Fkernel%2Flinux.git net: ethtool: netlink: Allow NULL nlattrs when getting a phy_device ethnl_req_get_phydev() is used to lookup a phy_device, in the case an ethtool netlink command targets a specific phydev within a netdev's topology. It takes as a parameter a const struct nlattr *header that's used for error handling : if (!phydev) { NL_SET_ERR_MSG_ATTR(extack, header, "no phy matching phyindex"); return ERR_PTR(-ENODEV); } In the notify path after a ->set operation however, there's no request attributes available. The typical callsite for the above function looks like: phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_XXX_HEADER], info->extack); So, when tb is NULL (such as in the ethnl notify path), we have a nice crash. It turns out that there's only the PLCA command that is in that case, as the other phydev-specific commands don't have a notification. This commit fixes the crash by passing the cmd index and the nlattr array separately, allowing NULL-checking it directly inside the helper. Fixes: c15e065b46dc ("net: ethtool: Allow passing a phy index for some commands") Signed-off-by: Maxime Chevallier Reviewed-by: Kory Maincent Reported-by: Parthiban Veerasooran Link: https://patch.msgid.link/20250301141114.97204-1-maxime.chevallier@bootlin.com Signed-off-by: Jakub Kicinski --- diff --git a/net/ethtool/cabletest.c b/net/ethtool/cabletest.c index f22051f33868a..84096f6b0236e 100644 --- a/net/ethtool/cabletest.c +++ b/net/ethtool/cabletest.c @@ -72,8 +72,8 @@ int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info) dev = req_info.dev; rtnl_lock(); - phydev = ethnl_req_get_phydev(&req_info, - tb[ETHTOOL_A_CABLE_TEST_HEADER], + phydev = ethnl_req_get_phydev(&req_info, tb, + ETHTOOL_A_CABLE_TEST_HEADER, info->extack); if (IS_ERR_OR_NULL(phydev)) { ret = -EOPNOTSUPP; @@ -339,8 +339,8 @@ int ethnl_act_cable_test_tdr(struct sk_buff *skb, struct genl_info *info) goto out_dev_put; rtnl_lock(); - phydev = ethnl_req_get_phydev(&req_info, - tb[ETHTOOL_A_CABLE_TEST_TDR_HEADER], + phydev = ethnl_req_get_phydev(&req_info, tb, + ETHTOOL_A_CABLE_TEST_TDR_HEADER, info->extack); if (IS_ERR_OR_NULL(phydev)) { ret = -EOPNOTSUPP; diff --git a/net/ethtool/linkstate.c b/net/ethtool/linkstate.c index af19e1bed303f..05a5f72c99fab 100644 --- a/net/ethtool/linkstate.c +++ b/net/ethtool/linkstate.c @@ -103,7 +103,7 @@ static int linkstate_prepare_data(const struct ethnl_req_info *req_base, struct phy_device *phydev; int ret; - phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_LINKSTATE_HEADER], + phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_LINKSTATE_HEADER, info->extack); if (IS_ERR(phydev)) { ret = PTR_ERR(phydev); diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c index b4c45207fa32e..734849a573691 100644 --- a/net/ethtool/netlink.c +++ b/net/ethtool/netlink.c @@ -211,7 +211,7 @@ int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info, } struct phy_device *ethnl_req_get_phydev(const struct ethnl_req_info *req_info, - const struct nlattr *header, + struct nlattr **tb, unsigned int header, struct netlink_ext_ack *extack) { struct phy_device *phydev; @@ -225,8 +225,8 @@ struct phy_device *ethnl_req_get_phydev(const struct ethnl_req_info *req_info, return req_info->dev->phydev; phydev = phy_link_topo_get_phy(req_info->dev, req_info->phy_index); - if (!phydev) { - NL_SET_ERR_MSG_ATTR(extack, header, + if (!phydev && tb) { + NL_SET_ERR_MSG_ATTR(extack, tb[header], "no phy matching phyindex"); return ERR_PTR(-ENODEV); } diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h index ff69ca0715dea..ec6ab5443a6f2 100644 --- a/net/ethtool/netlink.h +++ b/net/ethtool/netlink.h @@ -275,7 +275,8 @@ static inline void ethnl_parse_header_dev_put(struct ethnl_req_info *req_info) * ethnl_req_get_phydev() - Gets the phy_device targeted by this request, * if any. Must be called under rntl_lock(). * @req_info: The ethnl request to get the phy from. - * @header: The netlink header, used for error reporting. + * @tb: The netlink attributes array, for error reporting. + * @header: The netlink header index, used for error reporting. * @extack: The netlink extended ACK, for error reporting. * * The caller must hold RTNL, until it's done interacting with the returned @@ -289,7 +290,7 @@ static inline void ethnl_parse_header_dev_put(struct ethnl_req_info *req_info) * is returned. */ struct phy_device *ethnl_req_get_phydev(const struct ethnl_req_info *req_info, - const struct nlattr *header, + struct nlattr **tb, unsigned int header, struct netlink_ext_ack *extack); /** diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c index ed8f690f6bac8..e067cc234419d 100644 --- a/net/ethtool/phy.c +++ b/net/ethtool/phy.c @@ -125,7 +125,7 @@ static int ethnl_phy_parse_request(struct ethnl_req_info *req_base, struct phy_req_info *req_info = PHY_REQINFO(req_base); struct phy_device *phydev; - phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_PHY_HEADER], + phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_PHY_HEADER, extack); if (!phydev) return 0; diff --git a/net/ethtool/plca.c b/net/ethtool/plca.c index d95d92f173a6d..e1f7820a6158f 100644 --- a/net/ethtool/plca.c +++ b/net/ethtool/plca.c @@ -62,7 +62,7 @@ static int plca_get_cfg_prepare_data(const struct ethnl_req_info *req_base, struct phy_device *phydev; int ret; - phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_PLCA_HEADER], + phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_PLCA_HEADER, info->extack); // check that the PHY device is available and connected if (IS_ERR_OR_NULL(phydev)) { @@ -152,7 +152,7 @@ ethnl_set_plca(struct ethnl_req_info *req_info, struct genl_info *info) bool mod = false; int ret; - phydev = ethnl_req_get_phydev(req_info, tb[ETHTOOL_A_PLCA_HEADER], + phydev = ethnl_req_get_phydev(req_info, tb, ETHTOOL_A_PLCA_HEADER, info->extack); // check that the PHY device is available and connected if (IS_ERR_OR_NULL(phydev)) @@ -211,7 +211,7 @@ static int plca_get_status_prepare_data(const struct ethnl_req_info *req_base, struct phy_device *phydev; int ret; - phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_PLCA_HEADER], + phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_PLCA_HEADER, info->extack); // check that the PHY device is available and connected if (IS_ERR_OR_NULL(phydev)) { diff --git a/net/ethtool/pse-pd.c b/net/ethtool/pse-pd.c index 2819e2ba6be2d..4f6b99eab2a6c 100644 --- a/net/ethtool/pse-pd.c +++ b/net/ethtool/pse-pd.c @@ -64,7 +64,7 @@ static int pse_prepare_data(const struct ethnl_req_info *req_base, if (ret < 0) return ret; - phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_PSE_HEADER], + phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_PSE_HEADER, info->extack); if (IS_ERR(phydev)) return -ENODEV; @@ -261,7 +261,7 @@ ethnl_set_pse(struct ethnl_req_info *req_info, struct genl_info *info) struct phy_device *phydev; int ret; - phydev = ethnl_req_get_phydev(req_info, tb[ETHTOOL_A_PSE_HEADER], + phydev = ethnl_req_get_phydev(req_info, tb, ETHTOOL_A_PSE_HEADER, info->extack); ret = ethnl_set_pse_validate(phydev, info); if (ret) diff --git a/net/ethtool/stats.c b/net/ethtool/stats.c index 038a2558f0520..3ca8eb2a3b314 100644 --- a/net/ethtool/stats.c +++ b/net/ethtool/stats.c @@ -138,7 +138,7 @@ static int stats_prepare_data(const struct ethnl_req_info *req_base, struct phy_device *phydev; int ret; - phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_STATS_HEADER], + phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_STATS_HEADER, info->extack); if (IS_ERR(phydev)) return PTR_ERR(phydev); diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c index 6b76c05caba4d..f6a67109beda1 100644 --- a/net/ethtool/strset.c +++ b/net/ethtool/strset.c @@ -309,7 +309,7 @@ static int strset_prepare_data(const struct ethnl_req_info *req_base, return 0; } - phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_HEADER_FLAGS], + phydev = ethnl_req_get_phydev(req_base, tb, ETHTOOL_A_HEADER_FLAGS, info->extack); /* phydev can be NULL, check for errors only */