| From | Kamal Mostafa <> | Subject | [PATCH 3.19.y-ckt 144/156] sock, diag: fix panic in sock_diag_put_filterinfo | Date | Tue, 20 Oct 2015 14:38:05 -0700 |
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3.19.8-ckt8 -stable review patch. If anyone has any objections, please let me know.
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From: Daniel Borkmann <daniel@iogearbox.net>
commit b382c08656000c12a146723a153b85b13a855b49 upstream.
diag socket's sock_diag_put_filterinfo() dumps classic BPF programs upon request to user space (ss -0 -b). However, native eBPF programs attached to sockets (SO_ATTACH_BPF) cannot be dumped with this method:
Their orig_prog is always NULL. However, sock_diag_put_filterinfo() unconditionally tries to access its filter length resp. wants to copy the filter insns from there. Internal cBPF to eBPF transformations attached to sockets don't have this issue, as orig_prog state is kept.
It's currently only used by packet sockets. If we would want to add native eBPF support in the future, this needs to be done through a different attribute than PACKET_DIAG_FILTER to not confuse possible user space disassemblers that work on diag data.
Fixes: 89aa075832b0 ("net: sock: allow eBPF programs to be attached to sockets") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- net/core/sock_diag.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c index ad704c7..91c2630 100644 --- a/net/core/sock_diag.c +++ b/net/core/sock_diag.c @@ -69,6 +69,9 @@ int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk, goto out; fprog = filter->prog->orig_prog; + if (!fprog) + goto out; + flen = bpf_classic_proglen(fprog); attr = nla_reserve(skb, attrtype, flen); -- 1.9.1
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