On Fri, Feb 26, 2021 at 05:05:26PM +0300, Dan Carpenter wrote: > Here is a v2 of my check. I've changed it to mark all "->ssid" and > everything in "(struct ieee80211_network)" as protected. I'm just > playing around with it at this point to explore what works best. It's > impossible to know until after some results come back. > [ Added linux-wireless to the CC list. Here was the original check I wrote on Friday. https://lore.kernel.org/lkml/20210226140526.GG2222@kadam/ ] This check worked out pretty well. It's probably 50% bugs? Unfiltered results below. The trick of warning for "if (ststr(member, "->ssid")) " and the memcpy length couldn't be verified turned out to be the best. Protecting ieee80211_network didn't find anything. Sometimes we're copying from an existing (presumably verified) config to another config so the ->ssid_len is valid. An example of that is: drivers/staging/rtl8192e/rtllib_softmac.c:1685 rtllib_softmac_new_net() protected struct member '(struct rtllib_network)->ssid' overflow: rl='0-255' drivers/staging/rtl8192e/rtllib_softmac.c 1674 /* Save the essid so that if it is hidden, it is 1675 * replaced with the essid provided by the user. 1676 */ 1677 if (!ssidbroad) { 1678 memcpy(tmp_ssid, ieee->current_network.ssid, 1679 ieee->current_network.ssid_len); 1680 tmp_ssid_len = ieee->current_network.ssid_len; ^^^^^^^^^^^^ We can assume the existing ssid_len is valid 1681 } 1682 memcpy(&ieee->current_network, net, 1683 sizeof(ieee->current_network)); 1684 if (!ssidbroad) { 1685 memcpy(ieee->current_network.ssid, tmp_ssid, 1686 tmp_ssid_len); ^^^^^^^^^^^^ so this memcpy() won't overflow. It's easy enough for a human reviewer to make this sort of assumption, but Smatch can't. 1687 ieee->current_network.ssid_len = tmp_ssid_len; 1688 } All the code outside of drivers/ seems correct. They're mostly similar examples of copying the ssid from one valid existing config to another. The other places are using nla attrs like this: net/wireless/nl80211.c 14399 if (info->attrs[NL80211_ATTR_SSID]) { 14400 params.ssid.ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]); 14401 if (params.ssid.ssid_len == 0) 14402 return -EINVAL; 14403 memcpy(params.ssid.ssid, 14404 nla_data(info->attrs[NL80211_ATTR_SSID]), 14405 params.ssid.ssid_len); 14406 } Smatch doesn't parse nla attributes correctly. They're capped using the nl80211_policy[] array: net/wireless/nl80211.c 528 [NL80211_ATTR_SSID] = { .type = NLA_BINARY, 529 .len = IEEE80211_MAX_SSID_LEN }, But there are quite a few real bugs as well. If anyone wants to fix any of these just claim a bug, and I won't send a patch for that warning. :) Lee, I think you mentioned that you had found a related buffer overflow fix? Did the check find it? regards, dan carpenter drivers/staging/rtl8192u/r8192U_wx.c:335 r8192_wx_set_scan() protected struct member '(struct ieee80211_network)->ssid' overflow: rl='1-255' drivers/staging/rtl8192e/rtllib_softmac.c:1685 rtllib_softmac_new_net() protected struct member '(struct rtllib_network)->ssid' overflow: rl='0-255' drivers/staging/rtl8192e/rtl8192e/rtl_wx.c:412 _rtl92e_wx_set_scan() protected struct member '(struct rtllib_network)->ssid' overflow: rl='1-255' drivers/staging/rtl8188eu/core/rtw_ap.c:795 rtw_check_beacon_data() protected struct member '(struct ndis_802_11_ssid)->ssid' overflow: rl='1-255' drivers/staging/rtl8188eu/os_dep/ioctl_linux.c:1138 rtw_wx_set_scan() protected struct member '(struct ndis_802_11_ssid)->ssid' overflow: rl='1-127' drivers/net/wireless/ath/wcn36xx/smd.c:1571 wcn36xx_smd_set_bss_params() protected struct member '(struct wcn36xx_hal_mac_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/ath/ath11k/wmi.c:2148 ath11k_wmi_send_scan_start_cmd() protected struct member '(struct wmi_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/ath/wil6210/cfg80211.c:2100 wil_cfg80211_change_beacon() protected struct member '(struct wil6210_vif)->ssid' overflow: rl='0-255' drivers/net/wireless/ath/ath10k/wow.c:198 ath10k_wmi_pno_check() protected struct member '(struct wmi_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/ath/ath10k/wmi-tlv.c:2029 ath10k_wmi_tlv_op_gen_start_scan() protected struct member '(struct wmi_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/ath/ath10k/wmi-tlv.c:3929 ath10k_wmi_tlv_op_gen_config_pno_start() protected struct member '(struct wmi_ssid)->ssid' overflow: rl='0-u32max' drivers/net/wireless/ath/ath6kl/wmi.c:1884 ath6kl_wmi_connect_cmd() protected struct member '(struct wmi_connect_cmd)->ssid' overflow: rl='s32min-(-1),1-s32max' drivers/net/wireless/ath/ath6kl/cfg80211.c:932 ath6kl_set_probed_ssids() protected struct member '(struct cfg80211_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/ath/ath6kl/cfg80211.c:971 ath6kl_set_probed_ssids() protected struct member '(struct cfg80211_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/ath/ath6kl/cfg80211.c:1631 ath6kl_cfg80211_join_ibss() protected struct member '(struct ath6kl_vif)->ssid' overflow: rl='0-255' drivers/net/wireless/ath/ath6kl/cfg80211.c:2809 ath6kl_start_ap() protected struct member '(struct ath6kl_vif)->ssid' overflow: rl='0-65531' drivers/net/wireless/ath/ath6kl/cfg80211.c:2892 ath6kl_start_ap() protected struct member '(struct wmi_connect_cmd)->ssid' overflow: rl='0-65531' drivers/net/wireless/st/cw1200/sta.c:1293 cw1200_do_join() protected struct member '(struct wsm_join)->ssid' overflow: rl='0-255' drivers/net/wireless/st/cw1200/sta.c:2334 cw1200_start_ap() protected struct member '(struct wsm_start)->ssid' overflow: rl='0-255' drivers/net/wireless/quantenna/qtnfmac/event.c:573 qtnf_event_handle_external_auth() protected struct member '(struct cfg80211_ssid)->ssid' overflow: rl='1-255' drivers/net/wireless/marvell/mwifiex/uap_cmd.c:506 mwifiex_uap_bss_param_prepare() protected struct member '(struct host_cmd_tlv_ssid)->ssid' overflow: rl='1-u32max' drivers/net/wireless/marvell/mwifiex/join.c:428 mwifiex_cmd_802_11_associate() protected struct member '(struct mwifiex_ie_types_ssid_param_set)->ssid' overflow: rl='0-u16max' drivers/net/wireless/marvell/mwifiex/scan.c:933 mwifiex_config_scan() protected struct member '(struct mwifiex_ie_types_wildcard_ssid_params)->ssid' overflow: rl='0-255' drivers/net/wireless/marvell/mwifiex/scan.c:2383 mwifiex_cmd_802_11_bg_scan_config() protected struct member '(struct mwifiex_ie_types_wildcard_ssid_params)->ssid' overflow: rl='0-255' drivers/net/wireless/marvell/mwifiex/cfg80211.c:1999 mwifiex_cfg80211_start_ap() protected struct member '(struct mwifiex_802_11_ssid)->ssid' overflow: rl='1-65531' drivers/net/wireless/marvell/libertas/cfg.c:176 lbs_add_ssid_tlv() protected struct member '(struct mrvl_ie_ssid_param_set)->ssid' overflow: rl='s32min-s32max' drivers/net/wireless/marvell/libertas/cfg.c:1767 lbs_ibss_join_existing() protected struct member '(struct adhoc_bssdesc)->ssid' overflow: rl='0-255' drivers/net/wireless/marvell/libertas/cfg.c:1878 lbs_ibss_start_new() protected struct member '(struct cmd_ds_802_11_ad_hoc_start)->ssid' overflow: rl='0-255' drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:3708 brcmf_wowl_nd_results() protected struct member '(struct cfg80211_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/intel/iwlwifi/mvm/d3.c:1932 iwl_mvm_query_netdetect_reasons() protected struct member '(struct cfg80211_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/intel/iwlwifi/mvm/scan.c:486 iwl_scan_build_ssids() protected struct member '(struct iwl_ssid_ie)->ssid' overflow: rl='1-255' drivers/net/wireless/intel/iwlwifi/mvm/scan.c:500 iwl_scan_build_ssids() protected struct member '(struct iwl_ssid_ie)->ssid' overflow: rl='0-255' drivers/net/wireless/intel/iwlwifi/dvm/scan.c:721 iwlagn_request_scan() protected struct member '(struct iwl_ssid_ie)->ssid' overflow: rl='0-255' drivers/net/wireless/intel/ipw2x00/ipw2200.c:5870 ipw_adhoc_create() protected struct member '(struct libipw_network)->ssid' overflow: rl='0-255' drivers/net/wireless/intel/iwlegacy/3945-mac.c:2573 il3945_request_scan() protected struct member '(struct il_ssid_ie)->ssid' overflow: rl='1-255' drivers/net/wireless/intel/iwlegacy/4965-mac.c:919 il4965_request_scan() protected struct member '(struct il_ssid_ie)->ssid' overflow: rl='1-255' drivers/net/wireless/ti/wlcore/scan.c:351 wlcore_scan() protected struct member '(struct wl1271_scan)->ssid' overflow: rl='1-255' drivers/net/wireless/ti/wlcore/scan.c:410 wlcore_scan_sched_scan_ssid_list() protected struct member '(struct wl1271_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/ti/wlcore/scan.c:425 wlcore_scan_sched_scan_ssid_list() protected struct member '(struct wl1271_ssid)->ssid' overflow: rl='1-255' drivers/net/wireless/ti/wl18xx/scan.c:94 wl18xx_scan_send() protected struct member '(struct wl18xx_cmd_scan_params)->ssid' overflow: rl='0-255' drivers/net/wireless/ti/wl1251/cmd.c:459 wl1251_cmd_scan() protected struct member '(struct wl1251_scan_parameters)->ssid' overflow: rl='0-255' drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c:1338 mt76_connac_mcu_hw_scan() protected struct member '(struct mt76_connac_mcu_scan_ssid)->ssid' overflow: rl='1-255' drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c:1445 mt76_connac_mcu_sched_scan_req() protected struct member '(struct mt76_connac_mcu_scan_ssid)->ssid' overflow: rl='0-255' drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c:1452 mt76_connac_mcu_sched_scan_req() protected struct member '(struct mt76_connac_mcu_scan_match)->ssid' overflow: rl='0-255' net/wireless/nl80211.c:3890 nl80211_set_interface() protected struct member '(struct wireless_dev)->ssid' overflow: rl='0-255' net/wireless/nl80211.c:4001 nl80211_new_interface() protected struct member '(struct wireless_dev)->ssid' overflow: rl='0-255' net/wireless/nl80211.c:5503 nl80211_start_ap() protected struct member '(struct wireless_dev)->ssid' overflow: rl='0-255' net/wireless/nl80211.c:8382 nl80211_trigger_scan() protected struct member '(struct cfg80211_ssid)->ssid' overflow: rl='0-65527' net/wireless/nl80211.c:8836 nl80211_parse_sched_scan() protected struct member '(struct cfg80211_ssid)->ssid' overflow: rl='0-65527' net/wireless/nl80211.c:8874 nl80211_parse_sched_scan() protected struct member '(struct cfg80211_ssid)->ssid' overflow: rl='0-65531' net/wireless/nl80211.c:14403 nl80211_external_auth() protected struct member '(struct cfg80211_ssid)->ssid' overflow: rl='1-255' net/wireless/ibss.c:151 __cfg80211_join_ibss() protected struct member '(struct wireless_dev)->ssid' overflow: rl='0-255' net/wireless/ibss.c:424 cfg80211_ibss_wext_siwessid() protected struct member '(struct wireless_dev)->ssid' overflow: rl='0-u16max' net/wireless/mesh.c:212 __cfg80211_join_mesh() protected struct member '(struct wireless_dev)->ssid' overflow: rl='1-255' net/mac80211/ibss.c:330 __ieee80211_sta_join_ibss() protected struct member '(struct ieee80211_bss_conf)->ssid' overflow: rl='0-255' net/mac80211/ibss.c:1833 ieee80211_ibss_join() protected struct member '(struct ieee80211_if_ibss)->ssid' overflow: rl='0-255' net/mac80211/cfg.c:1132 ieee80211_start_ap() protected struct member '(struct ieee80211_bss_conf)->ssid' overflow: rl='1-65531' _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
