Hi Kees, I love your patch! Yet something to improve: [auto build test ERROR on staging/staging-testing] url: https://github.com/0day-ci/linux/commits/Kees-Cook/staging-rtl-Check-for-... base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git fa783154524a71ab74e293cd8251155e5971952b config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20220115/202201151447.WZ02BFf7-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/190b2c80a0e1844b5e38a9311830227d2... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Kees-Cook/staging-rtl-Check-for-NULL-header-value/20220115-122817 git checkout 190b2c80a0e1844b5e38a9311830227d27533471 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/staging/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/staging/rtl8712/rtl871x_recv.c: In function 'r8712_portctrl': 237 | ptr = precvframe->u.hdr.rx_data; | ^~~~~~~~~~ | precv_frame drivers/staging/rtl8712/rtl871x_recv.c:237:8: note: each undeclared identifier is reported only once for each function it appears in vim +237 drivers/staging/rtl8712/rtl871x_recv.c 223 224 /*###set the security information in the recv_frame */ 225 union recv_frame *r8712_portctrl(struct _adapter *adapter, 226 union recv_frame *precv_frame) 227 { 228 u8 *psta_addr, *ptr; 229 uint auth_alg; 230 struct recv_frame_hdr *pfhdr; 231 struct sta_info *psta; 232 struct sta_priv *pstapriv; 233 union recv_frame *prtnframe; 234 u16 ether_type; 235 236 pstapriv = &adapter->stapriv; 238 pfhdr = &precv_frame->u.hdr; 239 psta_addr = pfhdr->attrib.ta; 240 psta = r8712_get_stainfo(pstapriv, psta_addr); 241 auth_alg = adapter->securitypriv.AuthAlgrthm; 242 if (auth_alg == 2) { 243 /* get ether_type */ 244 ptr = ptr + pfhdr->attrib.hdrlen + LLC_HEADER_SIZE; 245 ether_type = get_unaligned_be16(ptr); 246 247 if (psta && psta->ieee8021x_blocked) { 248 /* blocked 249 * only accept EAPOL frame 250 */ 251 if (ether_type == 0x888e) { 252 prtnframe = precv_frame; 253 } else { 254 /*free this frame*/ 255 r8712_free_recvframe(precv_frame, 256 &adapter->recvpriv.free_recv_queue); 257 prtnframe = NULL; 258 } 259 } else { 260 /* allowed 261 * check decryption status, and decrypt the 262 * frame if needed 263 */ 264 prtnframe = precv_frame; 265 /* check is the EAPOL frame or not (Rekey) */ 266 if (ether_type == 0x888e) { 267 /* check Rekey */ 268 prtnframe = precv_frame; 269 } 270 } 271 } else { 272 prtnframe = precv_frame; 273 } 274 return prtnframe; 275 } 276 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org