When compiling with gcc 13.1 and CONFIG_FORTIFY_SOURCE=y, I've noticed the following: ... In function ‘fortify_memcpy_chk’, inlined from ‘ath12k_peer_assoc_h_he’ at drivers/net/wireless/ath/ath12k/mac.c:1640:2, inlined from ‘ath12k_peer_assoc_prepare’ at drivers/net/wireless/ath/ath12k/mac.c:2027:2: ./include/linux/fortify-string.h:529:25: warning: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 529 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In function ‘fortify_memcpy_chk’, inlined from ‘ath12k_peer_assoc_h_he’ at drivers/net/wireless/ath/ath12k/mac.c:1643:2, inlined from ‘ath12k_peer_assoc_prepare’ at drivers/net/wireless/ath/ath12k/mac.c:2027:2: ./include/linux/fortify-string.h:529:25: warning: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 529 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ... And this seems correct because: /* dst: u32[2], src: u8[6], size: 8 so 2 byte source overread */ memcpy(&arg->peer_he_cap_macinfo, he_cap->he_cap_elem.mac_cap_info, sizeof(arg->peer_he_cap_macinfo)); and: /* dst: u32[3], src: u8[11], size: 12 so 1 byte source overread */ memcpy(&arg->peer_he_cap_phyinfo, he_cap->he_cap_elem.phy_cap_info, sizeof(arg->peer_he_cap_phyinfo)); Dmitry