diff options
| author | Jason Baron <jbaron@akamai.com> | 2020-02-17 15:38:09 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-02-17 21:33:28 -0800 |
| commit | 8a9093c79863b58cc2f9874d7ae788f0d622a596 (patch) | |
| tree | f86256403d55b8cd2474e808e4ba0feb404aa012 | |
| parent | a81541041ceb55bcec9a8bb8ad3482263f0a205a (diff) | |
net: sched: correct flower port blocking
tc flower rules that are based on src or dst port blocking are sometimes
ineffective due to uninitialized stack data. __skb_flow_dissect() extracts
ports from the skb for tc flower to match against. However, the port
dissection is not done when when the FLOW_DIS_IS_FRAGMENT bit is set in
key_control->flags. All callers of __skb_flow_dissect(), zero-out the
key_control field except for fl_classify() as used by the flower
classifier. Thus, the FLOW_DIS_IS_FRAGMENT may be set on entry to
__skb_flow_dissect(), since key_control is allocated on the stack
and may not be initialized.
Since key_basic and key_control are present for all flow keys, let's
make sure they are initialized.
Fixes: 62230715fd24 ("flow_dissector: do not dissect l4 ports for fragments")
Co-developed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/flow_dissector.h | 9 | ||||
| -rw-r--r-- | net/sched/cls_flower.c | 1 |
2 files changed, 10 insertions, 0 deletions
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h index e9391e877f9a..628383915827 100644 --- a/include/net/flow_dissector.h +++ b/include/net/flow_dissector.h @@ -5,6 +5,7 @@ #include <linux/types.h> #include <linux/in6.h> #include <linux/siphash.h> +#include <linux/string.h> #include <uapi/linux/if_ether.h> struct sk_buff; @@ -348,4 +349,12 @@ struct bpf_flow_dissector { void *data_end; }; +static inline void +flow_dissector_init_keys(struct flow_dissector_key_control *key_control, + struct flow_dissector_key_basic *key_basic) +{ + memset(key_control, 0, sizeof(*key_control)); + memset(key_basic, 0, sizeof(*key_basic)); +} + #endif diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c index 7e54d2ab5254..d32d4233d337 100644 --- a/net/sched/cls_flower.c +++ b/net/sched/cls_flower.c @@ -305,6 +305,7 @@ static int fl_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct cls_fl_filter *f; list_for_each_entry_rcu(mask, &head->masks, list) { + flow_dissector_init_keys(&skb_key.control, &skb_key.basic); fl_clear_masked_range(&skb_key, mask); skb_flow_dissect_meta(skb, &mask->dissector, &skb_key); |