4.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
[ Upstream commit b382c08656000c12a146723a153b85b13a855b49 ]
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@xxxxxxxxxxxxx>
Acked-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
Acked-by: Alexei Starovoitov <ast@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/sock_diag.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -86,6 +86,9 @@ int sock_diag_put_filterinfo(bool may_re
goto out;
fprog = filter->prog->orig_prog;
+ if (!fprog)
+ goto out;
+
flen = bpf_classic_proglen(fprog);
attr = nla_reserve(skb, attrtype, flen);
--
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