Hi Jesper, url: https://github.com/0day-ci/linux/commits/Jesper-Dangaard-Brouer/bpf-New-approach-for-BPF-MTU-handling/20201028-002919 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git master config: i386-randconfig-m021-20201026 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 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>
New smatch warnings:
net/core/filter.c:5395 bpf_ipv4_fib_lookup() error: uninitialized symbol 'mtu'.
vim +/mtu +5395 net/core/filter.c
87f5fc7e48dd317 David Ahern 2018-05-09 5281 static int
bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
4f74fede40df8db David Ahern 2018-05-21 5282
u32 flags, bool check_mtu)
87f5fc7e48dd317 David Ahern 2018-05-09 5283 {
eba618abacade71 David Ahern 2019-04-02 5284 struct
fib_nh_common *nhc;
87f5fc7e48dd317 David Ahern 2018-05-09 5285 struct
in_device *in_dev;
87f5fc7e48dd317 David Ahern 2018-05-09 5286 struct
neighbour *neigh;
87f5fc7e48dd317 David Ahern 2018-05-09 5287 struct
net_device *dev;
87f5fc7e48dd317 David Ahern 2018-05-09 5288 struct
fib_result res;
87f5fc7e48dd317 David Ahern 2018-05-09 5289 struct flowi4
fl4;
87f5fc7e48dd317 David Ahern 2018-05-09 5290 int err;
4f74fede40df8db David Ahern 2018-05-21 5291 u32 mtu;
^^^^^^^^
87f5fc7e48dd317 David Ahern 2018-05-09 5292
87f5fc7e48dd317 David Ahern 2018-05-09 5293 dev =
dev_get_by_index_rcu(net, params->ifindex);
87f5fc7e48dd317 David Ahern 2018-05-09 5294 if
(unlikely(!dev))
87f5fc7e48dd317 David Ahern 2018-05-09 5295 return
-ENODEV;
87f5fc7e48dd317 David Ahern 2018-05-09 5296
87f5fc7e48dd317 David Ahern 2018-05-09 5297 /* verify
forwarding is enabled on this interface */
87f5fc7e48dd317 David Ahern 2018-05-09 5298 in_dev =
__in_dev_get_rcu(dev);
87f5fc7e48dd317 David Ahern 2018-05-09 5299 if
(unlikely(!in_dev || !IN_DEV_FORWARD(in_dev)))
4c79579b44b1876 David Ahern 2018-06-26 5300 return
BPF_FIB_LKUP_RET_FWD_DISABLED;
87f5fc7e48dd317 David Ahern 2018-05-09 5301
87f5fc7e48dd317 David Ahern 2018-05-09 5302 if (flags &
BPF_FIB_LOOKUP_OUTPUT) {
87f5fc7e48dd317 David Ahern 2018-05-09 5303
fl4.flowi4_iif = 1;
87f5fc7e48dd317 David Ahern 2018-05-09 5304
fl4.flowi4_oif = params->ifindex;
87f5fc7e48dd317 David Ahern 2018-05-09 5305 } else {
87f5fc7e48dd317 David Ahern 2018-05-09 5306
fl4.flowi4_iif = params->ifindex;
87f5fc7e48dd317 David Ahern 2018-05-09 5307
fl4.flowi4_oif = 0;
87f5fc7e48dd317 David Ahern 2018-05-09 5308 }
87f5fc7e48dd317 David Ahern 2018-05-09 5309 fl4.flowi4_tos
= params->tos & IPTOS_RT_MASK;
87f5fc7e48dd317 David Ahern 2018-05-09 5310
fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
87f5fc7e48dd317 David Ahern 2018-05-09 5311
fl4.flowi4_flags = 0;
87f5fc7e48dd317 David Ahern 2018-05-09 5312
87f5fc7e48dd317 David Ahern 2018-05-09 5313
fl4.flowi4_proto = params->l4_protocol;
87f5fc7e48dd317 David Ahern 2018-05-09 5314 fl4.daddr =
params->ipv4_dst;
87f5fc7e48dd317 David Ahern 2018-05-09 5315 fl4.saddr =
params->ipv4_src;
87f5fc7e48dd317 David Ahern 2018-05-09 5316 fl4.fl4_sport =
params->sport;
87f5fc7e48dd317 David Ahern 2018-05-09 5317 fl4.fl4_dport =
params->dport;
1869e226a7b3ef7 David Ahern 2020-09-13 5318
fl4.flowi4_multipath_hash = 0;
87f5fc7e48dd317 David Ahern 2018-05-09 5319
87f5fc7e48dd317 David Ahern 2018-05-09 5320 if (flags &
BPF_FIB_LOOKUP_DIRECT) {
87f5fc7e48dd317 David Ahern 2018-05-09 5321 u32
tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
87f5fc7e48dd317 David Ahern 2018-05-09 5322 struct
fib_table *tb;
87f5fc7e48dd317 David Ahern 2018-05-09 5323
87f5fc7e48dd317 David Ahern 2018-05-09 5324 tb =
fib_get_table(net, tbid);
87f5fc7e48dd317 David Ahern 2018-05-09 5325 if
(unlikely(!tb))
4c79579b44b1876 David Ahern 2018-06-26 5326
return BPF_FIB_LKUP_RET_NOT_FWDED;
87f5fc7e48dd317 David Ahern 2018-05-09 5327
87f5fc7e48dd317 David Ahern 2018-05-09 5328 err =
fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF);
87f5fc7e48dd317 David Ahern 2018-05-09 5329 } else {
87f5fc7e48dd317 David Ahern 2018-05-09 5330
fl4.flowi4_mark = 0;
87f5fc7e48dd317 David Ahern 2018-05-09 5331
fl4.flowi4_secid = 0;
87f5fc7e48dd317 David Ahern 2018-05-09 5332
fl4.flowi4_tun_key.tun_id = 0;
87f5fc7e48dd317 David Ahern 2018-05-09 5333
fl4.flowi4_uid = sock_net_uid(net, NULL);
87f5fc7e48dd317 David Ahern 2018-05-09 5334
87f5fc7e48dd317 David Ahern 2018-05-09 5335 err =
fib_lookup(net, &fl4, &res, FIB_LOOKUP_NOREF);
87f5fc7e48dd317 David Ahern 2018-05-09 5336 }
87f5fc7e48dd317 David Ahern 2018-05-09 5337
4c79579b44b1876 David Ahern 2018-06-26 5338 if (err) {
4c79579b44b1876 David Ahern 2018-06-26 5339 /* map
fib lookup errors to RTN_ type */
4c79579b44b1876 David Ahern 2018-06-26 5340 if (err
== -EINVAL)
4c79579b44b1876 David Ahern 2018-06-26 5341
return BPF_FIB_LKUP_RET_BLACKHOLE;
4c79579b44b1876 David Ahern 2018-06-26 5342 if (err
== -EHOSTUNREACH)
4c79579b44b1876 David Ahern 2018-06-26 5343
return BPF_FIB_LKUP_RET_UNREACHABLE;
4c79579b44b1876 David Ahern 2018-06-26 5344 if (err
== -EACCES)
4c79579b44b1876 David Ahern 2018-06-26 5345
return BPF_FIB_LKUP_RET_PROHIBIT;
4c79579b44b1876 David Ahern 2018-06-26 5346
4c79579b44b1876 David Ahern 2018-06-26 5347 return
BPF_FIB_LKUP_RET_NOT_FWDED;
4c79579b44b1876 David Ahern 2018-06-26 5348 }
4c79579b44b1876 David Ahern 2018-06-26 5349
4c79579b44b1876 David Ahern 2018-06-26 5350 if (res.type !=
RTN_UNICAST)
4c79579b44b1876 David Ahern 2018-06-26 5351 return
BPF_FIB_LKUP_RET_NOT_FWDED;
87f5fc7e48dd317 David Ahern 2018-05-09 5352
5481d73f81549e2 David Ahern 2019-06-03 5353 if
(fib_info_num_path(res.fi) > 1)
87f5fc7e48dd317 David Ahern 2018-05-09 5354
fib_select_path(net, &res, &fl4, NULL);
87f5fc7e48dd317 David Ahern 2018-05-09 5355
4f74fede40df8db David Ahern 2018-05-21 5356 if (check_mtu) {
4f74fede40df8db David Ahern 2018-05-21 5357 mtu =
ip_mtu_from_fib_result(&res, params->ipv4_dst);
88ffc2c2e37ebb3 Jesper Dangaard Brouer 2020-10-27 5358 if
(params->tot_len > mtu) {
88ffc2c2e37ebb3 Jesper Dangaard Brouer 2020-10-27 5359
params->mtu = mtu; /* union with tot_len */
4c79579b44b1876 David Ahern 2018-06-26 5360
return BPF_FIB_LKUP_RET_FRAG_NEEDED;
4f74fede40df8db David Ahern 2018-05-21 5361 }
88ffc2c2e37ebb3 Jesper Dangaard Brouer 2020-10-27 5362 }
"mtu" not initialized on else path.
4f74fede40df8db David Ahern 2018-05-21 5363
eba618abacade71 David Ahern 2019-04-02 5364 nhc = res.nhc;
87f5fc7e48dd317 David Ahern 2018-05-09 5365
87f5fc7e48dd317 David Ahern 2018-05-09 5366 /* do not
handle lwt encaps right now */
eba618abacade71 David Ahern 2019-04-02 5367 if
(nhc->nhc_lwtstate)
4c79579b44b1876 David Ahern 2018-06-26 5368 return
BPF_FIB_LKUP_RET_UNSUPP_LWT;
87f5fc7e48dd317 David Ahern 2018-05-09 5369
eba618abacade71 David Ahern 2019-04-02 5370 dev =
nhc->nhc_dev;
87f5fc7e48dd317 David Ahern 2018-05-09 5371
87f5fc7e48dd317 David Ahern 2018-05-09 5372
params->rt_metric = res.fi->fib_priority;
d1c362e1dd68a42 Toke Høiland-Jørgensen 2020-10-09 5373 params->ifindex
= dev->ifindex;
87f5fc7e48dd317 David Ahern 2018-05-09 5374
87f5fc7e48dd317 David Ahern 2018-05-09 5375 /* xdp and
cls_bpf programs are run in RCU-bh so
87f5fc7e48dd317 David Ahern 2018-05-09 5376 *
rcu_read_lock_bh is not needed here
87f5fc7e48dd317 David Ahern 2018-05-09 5377 */
6f5f68d05ec0f64 David Ahern 2019-04-05 5378 if
(likely(nhc->nhc_gw_family != AF_INET6)) {
6f5f68d05ec0f64 David Ahern 2019-04-05 5379 if
(nhc->nhc_gw_family)
6f5f68d05ec0f64 David Ahern 2019-04-05 5380
params->ipv4_dst = nhc->nhc_gw.ipv4;
6f5f68d05ec0f64 David Ahern 2019-04-05 5381
6f5f68d05ec0f64 David Ahern 2019-04-05 5382 neigh =
__ipv4_neigh_lookup_noref(dev,
6f5f68d05ec0f64 David Ahern 2019-04-05 5383
(__force u32)params->ipv4_dst);
6f5f68d05ec0f64 David Ahern 2019-04-05 5384 } else {
6f5f68d05ec0f64 David Ahern 2019-04-05 5385 struct
in6_addr *dst = (struct in6_addr *)params->ipv6_dst;
6f5f68d05ec0f64 David Ahern 2019-04-05 5386
6f5f68d05ec0f64 David Ahern 2019-04-05 5387
params->family = AF_INET6;
6f5f68d05ec0f64 David Ahern 2019-04-05 5388 *dst =
nhc->nhc_gw.ipv6;
6f5f68d05ec0f64 David Ahern 2019-04-05 5389 neigh =
__ipv6_neigh_lookup_noref_stub(dev, dst);
6f5f68d05ec0f64 David Ahern 2019-04-05 5390 }
6f5f68d05ec0f64 David Ahern 2019-04-05 5391
4c79579b44b1876 David Ahern 2018-06-26 5392 if (!neigh)
4c79579b44b1876 David Ahern 2018-06-26 5393 return
BPF_FIB_LKUP_RET_NO_NEIGH;
87f5fc7e48dd317 David Ahern 2018-05-09 5394
88ffc2c2e37ebb3 Jesper Dangaard Brouer 2020-10-27 @5395 return
bpf_fib_set_fwd_params(params, neigh, dev, mtu);
^^^
Uninitialized variable warning.
87f5fc7e48dd317 David Ahern 2018-05-09 5396 }
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
.config.gz
Description: application/gzip
