Hi Jesper, url: https://github.com/0day-ci/linux/commits/Jesper-Dangaard-Brouer/bpf-New-approach-for-BPF-MTU-handling-and-enforcement/20201007-000903 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: s390-randconfig-m031-20201002 (attached as .config) compiler: s390-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> smatch warnings: net/core/filter.c:5315 bpf_ipv4_fib_lookup() error: uninitialized symbol 'mtu'. vim +/mtu +5315 net/core/filter.c 87f5fc7e48dd31 David Ahern 2018-05-09 5202 static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params, 4f74fede40df8d David Ahern 2018-05-21 5203 u32 flags, bool check_mtu) 87f5fc7e48dd31 David Ahern 2018-05-09 5204 { eba618abacade7 David Ahern 2019-04-02 5205 struct fib_nh_common *nhc; 87f5fc7e48dd31 David Ahern 2018-05-09 5206 struct in_device *in_dev; 87f5fc7e48dd31 David Ahern 2018-05-09 5207 struct neighbour *neigh; 87f5fc7e48dd31 David Ahern 2018-05-09 5208 struct net_device *dev; 87f5fc7e48dd31 David Ahern 2018-05-09 5209 struct fib_result res; 87f5fc7e48dd31 David Ahern 2018-05-09 5210 struct flowi4 fl4; 87f5fc7e48dd31 David Ahern 2018-05-09 5211 int err; 4f74fede40df8d David Ahern 2018-05-21 5212 u32 mtu; 87f5fc7e48dd31 David Ahern 2018-05-09 5213 87f5fc7e48dd31 David Ahern 2018-05-09 5214 dev = dev_get_by_index_rcu(net, params->ifindex); 87f5fc7e48dd31 David Ahern 2018-05-09 5215 if (unlikely(!dev)) 87f5fc7e48dd31 David Ahern 2018-05-09 5216 return -ENODEV; 87f5fc7e48dd31 David Ahern 2018-05-09 5217 87f5fc7e48dd31 David Ahern 2018-05-09 5218 /* verify forwarding is enabled on this interface */ 87f5fc7e48dd31 David Ahern 2018-05-09 5219 in_dev = __in_dev_get_rcu(dev); 87f5fc7e48dd31 David Ahern 2018-05-09 5220 if (unlikely(!in_dev || !IN_DEV_FORWARD(in_dev))) 4c79579b44b187 David Ahern 2018-06-26 5221 return BPF_FIB_LKUP_RET_FWD_DISABLED; 87f5fc7e48dd31 David Ahern 2018-05-09 5222 87f5fc7e48dd31 David Ahern 2018-05-09 5223 if (flags & BPF_FIB_LOOKUP_OUTPUT) { 87f5fc7e48dd31 David Ahern 2018-05-09 5224 fl4.flowi4_iif = 1; 87f5fc7e48dd31 David Ahern 2018-05-09 5225 fl4.flowi4_oif = params->ifindex; 87f5fc7e48dd31 David Ahern 2018-05-09 5226 } else { 87f5fc7e48dd31 David Ahern 2018-05-09 5227 fl4.flowi4_iif = params->ifindex; 87f5fc7e48dd31 David Ahern 2018-05-09 5228 fl4.flowi4_oif = 0; 87f5fc7e48dd31 David Ahern 2018-05-09 5229 } 87f5fc7e48dd31 David Ahern 2018-05-09 5230 fl4.flowi4_tos = params->tos & IPTOS_RT_MASK; 87f5fc7e48dd31 David Ahern 2018-05-09 5231 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 87f5fc7e48dd31 David Ahern 2018-05-09 5232 fl4.flowi4_flags = 0; 87f5fc7e48dd31 David Ahern 2018-05-09 5233 87f5fc7e48dd31 David Ahern 2018-05-09 5234 fl4.flowi4_proto = params->l4_protocol; 87f5fc7e48dd31 David Ahern 2018-05-09 5235 fl4.daddr = params->ipv4_dst; 87f5fc7e48dd31 David Ahern 2018-05-09 5236 fl4.saddr = params->ipv4_src; 87f5fc7e48dd31 David Ahern 2018-05-09 5237 fl4.fl4_sport = params->sport; 87f5fc7e48dd31 David Ahern 2018-05-09 5238 fl4.fl4_dport = params->dport; 1869e226a7b3ef David Ahern 2020-09-13 5239 fl4.flowi4_multipath_hash = 0; 87f5fc7e48dd31 David Ahern 2018-05-09 5240 87f5fc7e48dd31 David Ahern 2018-05-09 5241 if (flags & BPF_FIB_LOOKUP_DIRECT) { 87f5fc7e48dd31 David Ahern 2018-05-09 5242 u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; 87f5fc7e48dd31 David Ahern 2018-05-09 5243 struct fib_table *tb; 87f5fc7e48dd31 David Ahern 2018-05-09 5244 87f5fc7e48dd31 David Ahern 2018-05-09 5245 tb = fib_get_table(net, tbid); 87f5fc7e48dd31 David Ahern 2018-05-09 5246 if (unlikely(!tb)) 4c79579b44b187 David Ahern 2018-06-26 5247 return BPF_FIB_LKUP_RET_NOT_FWDED; 87f5fc7e48dd31 David Ahern 2018-05-09 5248 87f5fc7e48dd31 David Ahern 2018-05-09 5249 err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); 87f5fc7e48dd31 David Ahern 2018-05-09 5250 } else { 87f5fc7e48dd31 David Ahern 2018-05-09 5251 fl4.flowi4_mark = 0; 87f5fc7e48dd31 David Ahern 2018-05-09 5252 fl4.flowi4_secid = 0; 87f5fc7e48dd31 David Ahern 2018-05-09 5253 fl4.flowi4_tun_key.tun_id = 0; 87f5fc7e48dd31 David Ahern 2018-05-09 5254 fl4.flowi4_uid = sock_net_uid(net, NULL); 87f5fc7e48dd31 David Ahern 2018-05-09 5255 87f5fc7e48dd31 David Ahern 2018-05-09 5256 err = fib_lookup(net, &fl4, &res, FIB_LOOKUP_NOREF); 87f5fc7e48dd31 David Ahern 2018-05-09 5257 } 87f5fc7e48dd31 David Ahern 2018-05-09 5258 4c79579b44b187 David Ahern 2018-06-26 5259 if (err) { 4c79579b44b187 David Ahern 2018-06-26 5260 /* map fib lookup errors to RTN_ type */ 4c79579b44b187 David Ahern 2018-06-26 5261 if (err == -EINVAL) 4c79579b44b187 David Ahern 2018-06-26 5262 return BPF_FIB_LKUP_RET_BLACKHOLE; 4c79579b44b187 David Ahern 2018-06-26 5263 if (err == -EHOSTUNREACH) 4c79579b44b187 David Ahern 2018-06-26 5264 return BPF_FIB_LKUP_RET_UNREACHABLE; 4c79579b44b187 David Ahern 2018-06-26 5265 if (err == -EACCES) 4c79579b44b187 David Ahern 2018-06-26 5266 return BPF_FIB_LKUP_RET_PROHIBIT; 4c79579b44b187 David Ahern 2018-06-26 5267 4c79579b44b187 David Ahern 2018-06-26 5268 return BPF_FIB_LKUP_RET_NOT_FWDED; 4c79579b44b187 David Ahern 2018-06-26 5269 } 4c79579b44b187 David Ahern 2018-06-26 5270 4c79579b44b187 David Ahern 2018-06-26 5271 if (res.type != RTN_UNICAST) 4c79579b44b187 David Ahern 2018-06-26 5272 return BPF_FIB_LKUP_RET_NOT_FWDED; 87f5fc7e48dd31 David Ahern 2018-05-09 5273 5481d73f81549e David Ahern 2019-06-03 5274 if (fib_info_num_path(res.fi) > 1) 87f5fc7e48dd31 David Ahern 2018-05-09 5275 fib_select_path(net, &res, &fl4, NULL); 87f5fc7e48dd31 David Ahern 2018-05-09 5276 4f74fede40df8d David Ahern 2018-05-21 5277 if (check_mtu) { 4f74fede40df8d David Ahern 2018-05-21 5278 mtu = ip_mtu_from_fib_result(&res, params->ipv4_dst); ab61fc7ee5c482 Jesper Dangaard Brouer 2020-10-06 5279 if (params->tot_len > mtu) { ab61fc7ee5c482 Jesper Dangaard Brouer 2020-10-06 5280 params->mtu = mtu; /* union with tot_len */ 4c79579b44b187 David Ahern 2018-06-26 5281 return BPF_FIB_LKUP_RET_FRAG_NEEDED; 4f74fede40df8d David Ahern 2018-05-21 5282 } ab61fc7ee5c482 Jesper Dangaard Brouer 2020-10-06 5283 } "mtu" is not initialized on else path. 4f74fede40df8d David Ahern 2018-05-21 5284 eba618abacade7 David Ahern 2019-04-02 5285 nhc = res.nhc; 87f5fc7e48dd31 David Ahern 2018-05-09 5286 87f5fc7e48dd31 David Ahern 2018-05-09 5287 /* do not handle lwt encaps right now */ eba618abacade7 David Ahern 2019-04-02 5288 if (nhc->nhc_lwtstate) 4c79579b44b187 David Ahern 2018-06-26 5289 return BPF_FIB_LKUP_RET_UNSUPP_LWT; 87f5fc7e48dd31 David Ahern 2018-05-09 5290 eba618abacade7 David Ahern 2019-04-02 5291 dev = nhc->nhc_dev; 87f5fc7e48dd31 David Ahern 2018-05-09 5292 87f5fc7e48dd31 David Ahern 2018-05-09 5293 params->rt_metric = res.fi->fib_priority; 87f5fc7e48dd31 David Ahern 2018-05-09 5294 87f5fc7e48dd31 David Ahern 2018-05-09 5295 /* xdp and cls_bpf programs are run in RCU-bh so 87f5fc7e48dd31 David Ahern 2018-05-09 5296 * rcu_read_lock_bh is not needed here 87f5fc7e48dd31 David Ahern 2018-05-09 5297 */ 6f5f68d05ec0f6 David Ahern 2019-04-05 5298 if (likely(nhc->nhc_gw_family != AF_INET6)) { 6f5f68d05ec0f6 David Ahern 2019-04-05 5299 if (nhc->nhc_gw_family) 6f5f68d05ec0f6 David Ahern 2019-04-05 5300 params->ipv4_dst = nhc->nhc_gw.ipv4; 6f5f68d05ec0f6 David Ahern 2019-04-05 5301 6f5f68d05ec0f6 David Ahern 2019-04-05 5302 neigh = __ipv4_neigh_lookup_noref(dev, 6f5f68d05ec0f6 David Ahern 2019-04-05 5303 (__force u32)params->ipv4_dst); 6f5f68d05ec0f6 David Ahern 2019-04-05 5304 } else { 6f5f68d05ec0f6 David Ahern 2019-04-05 5305 struct in6_addr *dst = (struct in6_addr *)params->ipv6_dst; 6f5f68d05ec0f6 David Ahern 2019-04-05 5306 6f5f68d05ec0f6 David Ahern 2019-04-05 5307 params->family = AF_INET6; 6f5f68d05ec0f6 David Ahern 2019-04-05 5308 *dst = nhc->nhc_gw.ipv6; 6f5f68d05ec0f6 David Ahern 2019-04-05 5309 neigh = __ipv6_neigh_lookup_noref_stub(dev, dst); 6f5f68d05ec0f6 David Ahern 2019-04-05 5310 } 6f5f68d05ec0f6 David Ahern 2019-04-05 5311 4c79579b44b187 David Ahern 2018-06-26 5312 if (!neigh) 4c79579b44b187 David Ahern 2018-06-26 5313 return BPF_FIB_LKUP_RET_NO_NEIGH; 87f5fc7e48dd31 David Ahern 2018-05-09 5314 ab61fc7ee5c482 Jesper Dangaard Brouer 2020-10-06 @5315 return bpf_fib_set_fwd_params(params, neigh, dev, mtu); ^^^ Uninitialized. 87f5fc7e48dd31 David Ahern 2018-05-09 5316 } --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
Attachment:
.config.gz
Description: application/gzip
