From ff4dd73dd2b4806419f8ff65cbce11d5019548d0 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 27 Feb 2017 17:15:28 +0100 Subject: [PATCH] mac80211_hwsim: check HWSIM_ATTR_RADIO_NAME length Unfortunately, the nla policy was defined to have HWSIM_ATTR_RADIO_NAME as an NLA_STRING, rather than NLA_NUL_STRING, so we can't use it as a NUL-terminated string in the kernel. Rather than break the API, kasprintf() the string to a new buffer to guarantee NUL termination. Reported-by: Andrew Zaborowski Signed-off-by: Johannes Berg --- drivers/net/wireless/mac80211_hwsim.c | 28 ++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 0889fc81ce9e..50c219fb1a52 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3056,6 +3056,7 @@ static int hwsim_register_received_nl(struct sk_buff *skb_2, static int hwsim_new_radio_nl(struct sk_buff *msg, struct genl_info *info) { struct hwsim_new_radio_params param = { 0 }; + const char *hwname = NULL; param.reg_strict = info->attrs[HWSIM_ATTR_REG_STRICT_REG]; param.p2p_device = info->attrs[HWSIM_ATTR_SUPPORT_P2P_DEVICE]; @@ -3069,8 +3070,14 @@ static int hwsim_new_radio_nl(struct sk_buff *msg, struct genl_info *info) if (info->attrs[HWSIM_ATTR_NO_VIF]) param.no_vif = true; - if (info->attrs[HWSIM_ATTR_RADIO_NAME]) - param.hwname = nla_data(info->attrs[HWSIM_ATTR_RADIO_NAME]); + if (info->attrs[HWSIM_ATTR_RADIO_NAME]) { + hwname = kasprintf(GFP_KERNEL, "%.*s", + nla_len(info->attrs[HWSIM_ATTR_RADIO_NAME]), + (char *)nla_data(info->attrs[HWSIM_ATTR_RADIO_NAME])); + if (!hwname) + return -ENOMEM; + param.hwname = hwname; + } if (info->attrs[HWSIM_ATTR_USE_CHANCTX]) param.use_chanctx = true; @@ -3098,11 +3105,15 @@ static int hwsim_del_radio_nl(struct sk_buff *msg, struct genl_info *info) s64 idx = -1; const char *hwname = NULL; - if (info->attrs[HWSIM_ATTR_RADIO_ID]) + if (info->attrs[HWSIM_ATTR_RADIO_ID]) { idx = nla_get_u32(info->attrs[HWSIM_ATTR_RADIO_ID]); - else if (info->attrs[HWSIM_ATTR_RADIO_NAME]) - hwname = (void *)nla_data(info->attrs[HWSIM_ATTR_RADIO_NAME]); - else + } else if (info->attrs[HWSIM_ATTR_RADIO_NAME]) { + hwname = kasprintf(GFP_KERNEL, "%.*s", + nla_len(info->attrs[HWSIM_ATTR_RADIO_NAME]), + (char *)nla_data(info->attrs[HWSIM_ATTR_RADIO_NAME])); + if (!hwname) + return -ENOMEM; + } else return -EINVAL; spin_lock_bh(&hwsim_radio_lock); @@ -3111,7 +3122,8 @@ static int hwsim_del_radio_nl(struct sk_buff *msg, struct genl_info *info) if (data->idx != idx) continue; } else { - if (strcmp(hwname, wiphy_name(data->hw->wiphy))) + if (!hwname || + strcmp(hwname, wiphy_name(data->hw->wiphy))) continue; } @@ -3122,10 +3134,12 @@ static int hwsim_del_radio_nl(struct sk_buff *msg, struct genl_info *info) spin_unlock_bh(&hwsim_radio_lock); mac80211_hwsim_del_radio(data, wiphy_name(data->hw->wiphy), info); + kfree(hwname); return 0; } spin_unlock_bh(&hwsim_radio_lock); + kfree(hwname); return -ENODEV; }