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 <l...@intel.com>
Reported-by: Dan Carpenter <dan.carpen...@oracle.com>
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 }
---
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https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
.config.gz
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