From 901bb9891855164fdcfcfdd9c3d25bcc800d3f5b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 28 May 2019 10:56:03 +0200 Subject: nl80211: require and validate vendor command policy Require that each vendor command give a policy of its sub-attributes in NL80211_ATTR_VENDOR_DATA, and then (stricly) check the contents, including the NLA_F_NESTED flag that we couldn't check on the outer layer because there we don't know yet. It is possible to use VENDOR_CMD_RAW_DATA for raw data, but then no nested data can be given (NLA_F_NESTED flag must be clear) and the data is just passed as is to the command. Signed-off-by: Johannes Berg --- net/wireless/core.c | 13 +++++++++++++ net/wireless/nl80211.c | 39 +++++++++++++++++++++++++++++++++++++-- 2 files changed, 50 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/wireless/core.c b/net/wireless/core.c index 037816163e70..fba0915fbd6f 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -859,6 +859,19 @@ int wiphy_register(struct wiphy *wiphy) return -EINVAL; } + for (i = 0; i < rdev->wiphy.n_vendor_commands; i++) { + /* + * Validate we have a policy (can be explicitly set to + * VENDOR_CMD_RAW_DATA which is non-NULL) and also that + * we have at least one of doit/dumpit. + */ + if (WARN_ON(!rdev->wiphy.vendor_commands[i].policy)) + return -EINVAL; + if (WARN_ON(!rdev->wiphy.vendor_commands[i].doit && + !rdev->wiphy.vendor_commands[i].dumpit)) + return -EINVAL; + } + #ifdef CONFIG_PM if (WARN_ON(rdev->wiphy.wowlan && rdev->wiphy.wowlan->n_patterns && (!rdev->wiphy.wowlan->pattern_min_len || diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 80e514872719..34e86539552e 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -12669,6 +12669,29 @@ static int nl80211_crit_protocol_stop(struct sk_buff *skb, return 0; } +static int nl80211_vendor_check_policy(const struct wiphy_vendor_command *vcmd, + struct nlattr *attr, + struct netlink_ext_ack *extack) +{ + if (vcmd->policy == VENDOR_CMD_RAW_DATA) { + if (attr->nla_type & NLA_F_NESTED) { + NL_SET_ERR_MSG_ATTR(extack, attr, + "unexpected nested data"); + return -EINVAL; + } + + return 0; + } + + if (!(attr->nla_type & NLA_F_NESTED)) { + NL_SET_ERR_MSG_ATTR(extack, attr, "expected nested data"); + return -EINVAL; + } + + return nl80211_validate_nested(attr, vcmd->maxattr, vcmd->policy, + extack); +} + static int nl80211_vendor_cmd(struct sk_buff *skb, struct genl_info *info) { struct cfg80211_registered_device *rdev = info->user_ptr[0]; @@ -12727,11 +12750,16 @@ static int nl80211_vendor_cmd(struct sk_buff *skb, struct genl_info *info) if (info->attrs[NL80211_ATTR_VENDOR_DATA]) { data = nla_data(info->attrs[NL80211_ATTR_VENDOR_DATA]); len = nla_len(info->attrs[NL80211_ATTR_VENDOR_DATA]); + + err = nl80211_vendor_check_policy(vcmd, + info->attrs[NL80211_ATTR_VENDOR_DATA], + info->extack); + if (err) + return err; } rdev->cur_cmd_info = info; - err = rdev->wiphy.vendor_commands[i].doit(&rdev->wiphy, wdev, - data, len); + err = vcmd->doit(&rdev->wiphy, wdev, data, len); rdev->cur_cmd_info = NULL; return err; } @@ -12818,6 +12846,13 @@ static int nl80211_prepare_vendor_dump(struct sk_buff *skb, if (attrbuf[NL80211_ATTR_VENDOR_DATA]) { data = nla_data(attrbuf[NL80211_ATTR_VENDOR_DATA]); data_len = nla_len(attrbuf[NL80211_ATTR_VENDOR_DATA]); + + err = nl80211_vendor_check_policy( + &(*rdev)->wiphy.vendor_commands[vcmd_idx], + attrbuf[NL80211_ATTR_VENDOR_DATA], + cb->extack); + if (err) + return err; } /* 0 is the first index - add 1 to parse only once */ -- cgit v1.2.3