Hi Cole, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on nf-next/master] [also build test WARNING on nf/master ipvs/master v5.14-rc3 next-20210727] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Cole-Dishington/net-netfilter-Fix-port-selection-of-FTP-for-NF_NAT_RANGE_PROTO_SPECIFIED/20210728-112306 base: https://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git master config: xtensa-allyesconfig (attached as .config) compiler: xtensa-linux-gcc (GCC) 10.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/2e0f4c593d92890a9a5b0098b3f20a6486b4019d git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Cole-Dishington/net-netfilter-Fix-port-selection-of-FTP-for-NF_NAT_RANGE_PROTO_SPECIFIED/20210728-112306 git checkout 2e0f4c593d92890a9a5b0098b3f20a6486b4019d # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross ARCH=xtensa If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> net/netfilter/nf_nat_core.c:363:6: warning: no previous prototype for 'nf_nat_l4proto_unique_tuple' [-Wmissing-prototypes] 363 | void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +/nf_nat_l4proto_unique_tuple +363 net/netfilter/nf_nat_core.c 357 358 /* Alter the per-proto part of the tuple (depending on maniptype), to 359 * give a unique tuple in the given range if possible. 360 * 361 * Per-protocol part of tuple is initialized to the incoming packet. 362 */ > 363 void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple, 364 const struct nf_nat_range2 *range, 365 enum nf_nat_manip_type maniptype, 366 const struct nf_conn *ct) 367 { 368 unsigned int range_size, min, max, i, attempts; 369 __be16 *keyptr; 370 u16 off; 371 static const unsigned int max_attempts = 128; 372 373 switch (tuple->dst.protonum) { 374 case IPPROTO_ICMP: 375 case IPPROTO_ICMPV6: 376 /* id is same for either direction... */ 377 keyptr = &tuple->src.u.icmp.id; 378 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) { 379 min = 0; 380 range_size = 65536; 381 } else { 382 min = ntohs(range->min_proto.icmp.id); 383 range_size = ntohs(range->max_proto.icmp.id) - 384 ntohs(range->min_proto.icmp.id) + 1; 385 } 386 goto find_free_id; 387 #if IS_ENABLED(CONFIG_NF_CT_PROTO_GRE) 388 case IPPROTO_GRE: 389 /* If there is no master conntrack we are not PPTP, 390 do not change tuples */ 391 if (!ct->master) 392 return; 393 394 if (maniptype == NF_NAT_MANIP_SRC) 395 keyptr = &tuple->src.u.gre.key; 396 else 397 keyptr = &tuple->dst.u.gre.key; 398 399 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) { 400 min = 1; 401 range_size = 65535; 402 } else { 403 min = ntohs(range->min_proto.gre.key); 404 range_size = ntohs(range->max_proto.gre.key) - min + 1; 405 } 406 goto find_free_id; 407 #endif 408 case IPPROTO_UDP: 409 case IPPROTO_UDPLITE: 410 case IPPROTO_TCP: 411 case IPPROTO_SCTP: 412 case IPPROTO_DCCP: 413 if (maniptype == NF_NAT_MANIP_SRC) 414 keyptr = &tuple->src.u.all; 415 else 416 keyptr = &tuple->dst.u.all; 417 418 break; 419 default: 420 return; 421 } 422 423 /* If no range specified... */ 424 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) { 425 /* If it's dst rewrite, can't change port */ 426 if (maniptype == NF_NAT_MANIP_DST) 427 return; 428 429 if (ntohs(*keyptr) < 1024) { 430 /* Loose convention: >> 512 is credential passing */ 431 if (ntohs(*keyptr) < 512) { 432 min = 1; 433 range_size = 511 - min + 1; 434 } else { 435 min = 600; 436 range_size = 1023 - min + 1; 437 } 438 } else { 439 min = 1024; 440 range_size = 65535 - 1024 + 1; 441 } 442 } else { 443 min = ntohs(range->min_proto.all); 444 max = ntohs(range->max_proto.all); 445 if (unlikely(max < min)) 446 swap(max, min); 447 range_size = max - min + 1; 448 } 449 450 find_free_id: 451 if (range->flags & NF_NAT_RANGE_PROTO_OFFSET) 452 off = (ntohs(*keyptr) - ntohs(range->base_proto.all)); 453 else 454 off = prandom_u32(); 455 456 attempts = range_size; 457 if (attempts > max_attempts) 458 attempts = max_attempts; 459 460 /* We are in softirq; doing a search of the entire range risks 461 * soft lockup when all tuples are already used. 462 * 463 * If we can't find any free port from first offset, pick a new 464 * one and try again, with ever smaller search window. 465 */ 466 another_round: 467 for (i = 0; i < attempts; i++, off++) { 468 *keyptr = htons(min + off % range_size); 469 if (!nf_nat_used_tuple(tuple, ct)) 470 return; 471 } 472 473 if (attempts >= range_size || attempts < 16) 474 return; 475 attempts /= 2; 476 off = prandom_u32(); 477 goto another_round; 478 } 479 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org