| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.1 137/159] sched: cls_bpf: fix panic on filter replace | Date | Sat, 26 Sep 2015 13:56:23 -0700 |
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4.1-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Borkmann <daniel@iogearbox.net>
[ Upstream commit f6bfc46da6292b630ba389592123f0dd02066172 ]
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/sched/cls_bpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/sched/cls_bpf.c +++ b/net/sched/cls_bpf.c @@ -364,7 +364,7 @@ static int cls_bpf_change(struct net *ne 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 {
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