From: Cong Wang <cong.w...@bytedance.com>
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+2624e3778b18fc497...@syzkaller.appspotmail.com
Fixes: 0a6e77784f49 ("net/sched: allow flower to match tunnel options")
Fixes: 79b1011cb33d ("net: sched: allow flower to match erspan options")
Cc: Pieter Jansen van Vuuren <pieter.jansenvanvuu...@netronome.com>
Cc: Jamal Hadi Salim <j...@mojatatu.com>
Cc: Xin Long <lucien....@gmail.com>
Cc: Jiri Pirko <j...@resnulli.us>
Signed-off-by: Cong Wang <cong.w...@bytedance.com>
---
net/sched/cls_flower.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 1319986693fc..e265c443536e 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -1272,6 +1272,8 @@ 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))
+ return -EINVAL;
}
nla_for_each_attr(nla_opt_key, nla_enc_key,
@@ -1308,7 +1310,7 @@ static int fl_set_enc_opt(struct nlattr **tb, struct
fl_flow_key *key,
return -EINVAL;
}
- if (msk_depth)
+ if (nla_ok(nla_opt_msk, msk_depth))
nla_opt_msk = nla_next(nla_opt_msk, &msk_depth);
break;
case TCA_FLOWER_KEY_ENC_OPTS_VXLAN:
@@ -1341,7 +1343,7 @@ static int fl_set_enc_opt(struct nlattr **tb, struct
fl_flow_key *key,
return -EINVAL;
}
- if (msk_depth)
+ if (nla_ok(nla_opt_msk, msk_depth))
nla_opt_msk = nla_next(nla_opt_msk, &msk_depth);
break;
case TCA_FLOWER_KEY_ENC_OPTS_ERSPAN:
@@ -1374,7 +1376,7 @@ static int fl_set_enc_opt(struct nlattr **tb, struct
fl_flow_key *key,
return -EINVAL;
}
- if (msk_depth)
+ if (nla_ok(nla_opt_msk, msk_depth))
nla_opt_msk = nla_next(nla_opt_msk, &msk_depth);
break;
default:
--
2.25.1
