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authorDaniel Borkmann <daniel@iogearbox.net>2015-09-02 14:00:36 +0200
committerDavid S. Miller <davem@davemloft.net>2015-09-02 11:29:29 -0700
commitb382c08656000c12a146723a153b85b13a855b49 (patch)
tree1a9404a05caebe9bebf9404027d580264be29ee7
parent20a17bf6c04e3eca8824c930ecc55ab832558e3b (diff)
sock, diag: fix panic in sock_diag_put_filterinfo
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>
-rw-r--r--net/core/sock_diag.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index d79866c5f8bc..817622f3dbb7 100644
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -90,6 +90,9 @@ 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);