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authorCong Wang <cong.wang@bytedance.com>2021-01-15 10:50:24 -0800
committerJakub Kicinski <kuba@kernel.org>2021-01-15 15:48:53 -0800
commitc96adff95619178e2118925578343ad54857c80c (patch)
tree33cee1a4b529d142551ac9a95ef517c3882df21f /net
parentb7ba6cfabc42fc846eb96e33f1edcd3ea6290a27 (diff)
cls_flower: call nla_ok() before nla_next()
fl_set_enc_opt() simply checks if there are still bytes left to parse, but this is not sufficent as syzbot seems to be able to generate malformatted netlink messages. nla_ok() is more strict so should be used to validate the next nlattr here. And nla_validate_nested_deprecated() has less strict check too, it is probably too late to switch to the strict version, but we can just call nla_ok() too after it. Reported-and-tested-by: syzbot+2624e3778b18fc497c92@syzkaller.appspotmail.com Fixes: 0a6e77784f49 ("net/sched: allow flower to match tunnel options") Fixes: 79b1011cb33d ("net: sched: allow flower to match erspan options") Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Xin Long <lucien.xin@gmail.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Link: https://lore.kernel.org/r/20210115185024.72298-1-xiyou.wangcong@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/sched/cls_flower.c22
1 files changed, 13 insertions, 9 deletions
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 1319986693fc..84f932532db7 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -1272,6 +1272,10 @@ static int fl_set_enc_opt(struct nlattr **tb, struct fl_flow_key *key,
nla_opt_msk = nla_data(tb[TCA_FLOWER_KEY_ENC_OPTS_MASK]);
msk_depth = nla_len(tb[TCA_FLOWER_KEY_ENC_OPTS_MASK]);
+ if (!nla_ok(nla_opt_msk, msk_depth)) {
+ NL_SET_ERR_MSG(extack, "Invalid nested attribute for masks");
+ return -EINVAL;
+ }
}
nla_for_each_attr(nla_opt_key, nla_enc_key,
@@ -1307,9 +1311,6 @@ static int fl_set_enc_opt(struct nlattr **tb, struct fl_flow_key *key,
NL_SET_ERR_MSG(extack, "Key and mask miss aligned");
return -EINVAL;
}
-
- if (msk_depth)
- nla_opt_msk = nla_next(nla_opt_msk, &msk_depth);
break;
case TCA_FLOWER_KEY_ENC_OPTS_VXLAN:
if (key->enc_opts.dst_opt_type) {
@@ -1340,9 +1341,6 @@ static int fl_set_enc_opt(struct nlattr **tb, struct fl_flow_key *key,
NL_SET_ERR_MSG(extack, "Key and mask miss aligned");
return -EINVAL;
}
-
- if (msk_depth)
- nla_opt_msk = nla_next(nla_opt_msk, &msk_depth);
break;
case TCA_FLOWER_KEY_ENC_OPTS_ERSPAN:
if (key->enc_opts.dst_opt_type) {
@@ -1373,14 +1371,20 @@ static int fl_set_enc_opt(struct nlattr **tb, struct fl_flow_key *key,
NL_SET_ERR_MSG(extack, "Key and mask miss aligned");
return -EINVAL;
}
-
- if (msk_depth)
- nla_opt_msk = nla_next(nla_opt_msk, &msk_depth);
break;
default:
NL_SET_ERR_MSG(extack, "Unknown tunnel option type");
return -EINVAL;
}
+
+ if (!msk_depth)
+ continue;
+
+ if (!nla_ok(nla_opt_msk, msk_depth)) {
+ NL_SET_ERR_MSG(extack, "A mask attribute is invalid");
+ return -EINVAL;
+ }
+ nla_opt_msk = nla_next(nla_opt_msk, &msk_depth);
}
return 0;