In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memcpy(), memmove(), and memset(), avoid intentionally writing across neighboring fields.
libipw_read_qos_param_element() copies a struct libipw_info_element into a struct libipw_qos_information_element, but is actually wanting to copy into the larger struct libipw_qos_parameter_info (the contents of ac_params_record[] is later examined). Refactor the routine to perform centralized checks, and copy the entire contents directly (since the id and len members match the elementID and length members):
struct libipw_info_element { u8 id; u8 len; u8 data[]; } __packed;
struct libipw_qos_information_element { u8 elementID; u8 length; u8 qui[QOS_OUI_LEN]; u8 qui_type; u8 qui_subtype; u8 version; u8 ac_info; } __packed;
struct libipw_qos_parameter_info { struct libipw_qos_information_element info_element; u8 reserved; struct libipw_qos_ac_parameter ac_params_record[QOS_QUEUE_NUM]; } __packed;
Cc: Stanislav Yakovlev stas.yakovlev@gmail.com Cc: Kalle Valo kvalo@codeaurora.org Cc: "David S. Miller" davem@davemloft.net Cc: Jakub Kicinski kuba@kernel.org Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook keescook@chromium.org --- .../net/wireless/intel/ipw2x00/libipw_rx.c | 56 ++++++------------- 1 file changed, 17 insertions(+), 39 deletions(-)
diff --git a/drivers/net/wireless/intel/ipw2x00/libipw_rx.c b/drivers/net/wireless/intel/ipw2x00/libipw_rx.c index 5a2a723e480b..7a684b76f39b 100644 --- a/drivers/net/wireless/intel/ipw2x00/libipw_rx.c +++ b/drivers/net/wireless/intel/ipw2x00/libipw_rx.c @@ -927,7 +927,8 @@ static u8 qos_oui[QOS_OUI_LEN] = { 0x00, 0x50, 0xF2 }; static int libipw_verify_qos_info(struct libipw_qos_information_element *info_element, int sub_type) { - + if (info_element->elementID != QOS_ELEMENT_ID) + return -1; if (info_element->qui_subtype != sub_type) return -1; if (memcmp(info_element->qui, qos_oui, QOS_OUI_LEN)) @@ -943,57 +944,34 @@ static int libipw_verify_qos_info(struct libipw_qos_information_element /* * Parse a QoS parameter element */ -static int libipw_read_qos_param_element(struct libipw_qos_parameter_info - *element_param, struct libipw_info_element - *info_element) +static int libipw_read_qos_param_element( + struct libipw_qos_parameter_info *element_param, + struct libipw_info_element *info_element) { - int ret = 0; - u16 size = sizeof(struct libipw_qos_parameter_info) - 2; + size_t size = sizeof(*element_param);
- if ((info_element == NULL) || (element_param == NULL)) + if (!element_param || !info_element || info_element->len != size - 2) return -1;
- if (info_element->id == QOS_ELEMENT_ID && info_element->len == size) { - memcpy(element_param->info_element.qui, info_element->data, - info_element->len); - element_param->info_element.elementID = info_element->id; - element_param->info_element.length = info_element->len; - } else - ret = -1; - if (ret == 0) - ret = libipw_verify_qos_info(&element_param->info_element, - QOS_OUI_PARAM_SUB_TYPE); - return ret; + memcpy(element_param, info_element, size); + return libipw_verify_qos_info(&element_param->info_element, + QOS_OUI_PARAM_SUB_TYPE); }
/* * Parse a QoS information element */ -static int libipw_read_qos_info_element(struct - libipw_qos_information_element - *element_info, struct libipw_info_element - *info_element) +static int libipw_read_qos_info_element( + struct libipw_qos_information_element *element_info, + struct libipw_info_element *info_element) { - int ret = 0; - u16 size = sizeof(struct libipw_qos_information_element) - 2; + size_t size = sizeof(struct libipw_qos_information_element) - 2;
- if (element_info == NULL) + if (!element_info || !info_element || info_element->len != size - 2) return -1; - if (info_element == NULL) - return -1; - - if ((info_element->id == QOS_ELEMENT_ID) && (info_element->len == size)) { - memcpy(element_info->qui, info_element->data, - info_element->len); - element_info->elementID = info_element->id; - element_info->length = info_element->len; - } else - ret = -1;
- if (ret == 0) - ret = libipw_verify_qos_info(element_info, - QOS_OUI_INFO_SUB_TYPE); - return ret; + memcpy(element_info, info_element, size); + return libipw_verify_qos_info(element_info, QOS_OUI_INFO_SUB_TYPE); }
/*