On Tue, 2021-07-27 at 13:58 -0700, Kees Cook wrote: > > +++ b/include/linux/ieee80211.h > @@ -297,9 +297,11 @@ static inline u16 ieee80211_sn_sub(u16 sn1, u16 sn2) > struct ieee80211_hdr { > __le16 frame_control; > __le16 duration_id; > - u8 addr1[ETH_ALEN]; > - u8 addr2[ETH_ALEN]; > - u8 addr3[ETH_ALEN]; > + struct_group(addrs, > + u8 addr1[ETH_ALEN]; > + u8 addr2[ETH_ALEN]; > + u8 addr3[ETH_ALEN]; > + ); > __le16 seq_ctrl; > u8 addr4[ETH_ALEN]; > } __packed __aligned(2); This file isn't really just lib80211, it's also used by everyone else for 802.11, but I guess that's OK - after all, this doesn't really result in any changes here. > +++ b/net/wireless/lib80211_crypt_ccmp.c > @@ -136,7 +136,8 @@ static int ccmp_init_iv_and_aad(const struct ieee80211_hdr *hdr, > pos = (u8 *) hdr; > aad[0] = pos[0] & 0x8f; > aad[1] = pos[1] & 0xc7; > - memcpy(aad + 2, hdr->addr1, 3 * ETH_ALEN); > + BUILD_BUG_ON(sizeof(hdr->addrs) != 3 * ETH_ALEN); > + memcpy(aad + 2, &hdr->addrs, ETH_ALEN); However, how is it you don't need the same change in net/mac80211/wpa.c? We have three similar instances: /* AAD (extra authenticate-only data) / masked 802.11 header * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ put_unaligned_be16(len_a, &aad[0]); put_unaligned(mask_fc, (__le16 *)&aad[2]); memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); and memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); and memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN); so those should also be changed, it seems? In which case I'd probably prefer to do this separately from the staging drivers ... johannes