sock, diag: fix panic in sock_diag_put_filterinfo
authorDaniel Borkmann <daniel@iogearbox.net>
Wed, 2 Sep 2015 12:00:36 +0000 (14:00 +0200)
committerDavid S. Miller <davem@davemloft.net>
Wed, 2 Sep 2015 18:29:29 +0000 (11:29 -0700)
commitb382c08656000c12a146723a153b85b13a855b49
tree1a9404a05caebe9bebf9404027d580264be29ee7
parent20a17bf6c04e3eca8824c930ecc55ab832558e3b
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>
net/core/sock_diag.c