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authorDaniel Borkmann <daniel@iogearbox.net>2015-07-17 22:38:43 +0200
committerDavid S. Miller <davem@davemloft.net>2015-07-21 00:25:02 -0700
commitf6bfc46da6292b630ba389592123f0dd02066172 (patch)
treee43402df77d5320662706769e70b5e783fadeb1d /net/sched
parent27dfead164451971f2c3778857b43690e7afaa8b (diff)
downloadlinux-f6bfc46da6292b630ba389592123f0dd02066172.tar.gz
sched: cls_bpf: fix panic on filter replace
The following test case causes a NULL pointer dereference in cls_bpf:

  FOO="1,6 0 0 4294967295,"
  tc filter add dev foo parent 1: bpf bytecode "$FOO" flowid 1:1 action ok
  tc filter replace dev foo parent 1: pref 49152 handle 0x1 \
            bpf bytecode "$FOO" flowid 1:1 action drop

The problem is that commit 1f947bf151e9 ("net: sched: rcu'ify cls_bpf")
accidentally swapped the arguments of list_replace_rcu(), the old
element needs to be the first argument and the new element the second.

Fixes: 1f947bf151e9 ("net: sched: rcu'ify cls_bpf")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/cls_bpf.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index c79ecfd36e0f..e5168f8b9640 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -378,7 +378,7 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 		goto errout;
 
 	if (oldprog) {
-		list_replace_rcu(&prog->link, &oldprog->link);
+		list_replace_rcu(&oldprog->link, &prog->link);
 		tcf_unbind_filter(tp, &oldprog->res);
 		call_rcu(&oldprog->rcu, __cls_bpf_delete_prog);
 	} else {