Hello Lorenzo Bianconi,
The patch 6b7f9aff7c67: "mt76: mt7915: introduce 802.11ax multi-bss
support" from Mar 15, 2022, leads to the following Smatch static
checker warning:
drivers/net/wireless/mediatek/mt76/mt7915/mcu.c:1872 mt7915_mcu_beacon_mbss()
error: undefined (user controlled) shift '(((1))) << (data[2])'
drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
1828 static void
1829 mt7915_mcu_beacon_mbss(struct sk_buff *rskb, struct sk_buff *skb,
1830 struct ieee80211_vif *vif, struct bss_info_bcn *bcn,
1831 struct ieee80211_mutable_offsets *offs)
1832 {
1833 struct bss_info_bcn_mbss *mbss;
1834 const struct element *elem;
1835 struct tlv *tlv;
1836
1837 if (!vif->bss_conf.bssid_indicator)
1838 return;
1839
1840 tlv = mt7915_mcu_add_nested_subtlv(rskb, BSS_INFO_BCN_MBSSID,
1841 sizeof(*mbss), &bcn->sub_ntlv,
1842 &bcn->len);
1843
1844 mbss = (struct bss_info_bcn_mbss *)tlv;
1845 mbss->offset[0] = cpu_to_le16(offs->tim_offset);
1846 mbss->bitmap = cpu_to_le32(1);
1847
1848 for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID,
1849 &skb->data[offs->mbssid_off],
1850 skb->len - offs->mbssid_off) {
1851 const struct element *sub_elem;
1852
1853 if (elem->datalen < 2)
1854 continue;
1855
1856 for_each_element(sub_elem, elem->data + 1, elem->datalen - 1) {
1857 const u8 *data;
1858
1859 if (sub_elem->id || sub_elem->datalen < 4)
1860 continue; /* not a valid BSS profile */
1861
1862 /* Find WLAN_EID_MULTI_BSSID_IDX
1863 * in the merged nontransmitted profile
1864 */
1865 data = cfg80211_find_ie(WLAN_EID_MULTI_BSSID_IDX,
1866 sub_elem->data,
1867 sub_elem->datalen);
1868 if (!data || data[1] < 1 || !data[2])
This probably needs a "|| data[2] > 31" but maybe using a define?
1869 continue;
1870
1871 mbss->offset[data[2]] = cpu_to_le16(data - skb->data);
--> 1872 mbss->bitmap |= cpu_to_le32(BIT(data[2]));
1873 }
1874 }
1875 }
regards,
dan carpenter
