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| author | Daniel Borkmann <dborkman@redhat.com> | 2015-01-22 09:41:02 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-01-26 23:50:19 (GMT) |
| commit | 3f2ab135946dcd4eb6af92a53d6d4bd35e7526ca (patch) | |
| tree | 8d640016c0d8f2edd82147c2c24694f0f0ea3bd0 | |
| parent | 7913ecf69e24bd7575e0d0325eda3b43c8cfa749 (diff) | |
| download | linux-3f2ab135946dcd4eb6af92a53d6d4bd35e7526ca.tar.xz | |
net: cls_bpf: fix auto generation of per list handles
When creating a bpf classifier in tc with priority collisions and
invoking automatic unique handle assignment, cls_bpf_grab_new_handle()
will return a wrong handle id which in fact is non-unique. Usually
altering of specific filters is being addressed over major id, but
in case of collisions we result in a filter chain, where handle ids
address individual cls_bpf_progs inside the classifier.
Issue is, in cls_bpf_grab_new_handle() we probe for head->hgen handle
in cls_bpf_get() and in case we found a free handle, we're supposed
to use exactly head->hgen. In case of insufficient numbers of handles,
we bail out later as handle id 0 is not allowed.
Fixes: 7d1d65cb84e1 ("net: sched: cls_bpf: add BPF-based classifier")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/sched/cls_bpf.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c index 49e5fa8..f59adf8 100644 --- a/net/sched/cls_bpf.c +++ b/net/sched/cls_bpf.c @@ -220,15 +220,21 @@ static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp, struct cls_bpf_head *head) { unsigned int i = 0x80000000; + u32 handle; do { if (++head->hgen == 0x7FFFFFFF) head->hgen = 1; } while (--i > 0 && cls_bpf_get(tp, head->hgen)); - if (i == 0) + + if (unlikely(i == 0)) { pr_err("Insufficient number of handles\n"); + handle = 0; + } else { + handle = head->hgen; + } - return i; + return handle; } static int cls_bpf_change(struct net *net, struct sk_buff *in_skb, |