diff options
| author | Willem de Bruijn <willemb@google.com> | 2019-05-31 12:37:23 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-06-02 18:10:14 -0700 |
| commit | afa0925c6fcc6a8f610e996ca09bc3215048033c (patch) | |
| tree | 626dcaed42ebd07593d937544ee61346102ea05c /net/packet | |
| parent | 8c268598192df9a07ca967f6a8d5f12c3c1b3888 (diff) | |
| download | linux-afa0925c6fcc6a8f610e996ca09bc3215048033c.tar.gz linux-afa0925c6fcc6a8f610e996ca09bc3215048033c.tar.bz2 linux-afa0925c6fcc6a8f610e996ca09bc3215048033c.zip | |
packet: unconditionally free po->rollover
Rollover used to use a complex RCU mechanism for assignment, which had
a race condition. The below patch fixed the bug and greatly simplified
the logic.
The feature depends on fanout, but the state is private to the socket.
Fanout_release returns f only when the last member leaves and the
fanout struct is to be freed.
Destroy rollover unconditionally, regardless of fanout state.
Fixes: 57f015f5eccf2 ("packet: fix crash in fanout_demux_rollover()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Diagnosed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/packet')
| -rw-r--r-- | net/packet/af_packet.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index fbc775fbf712..d4889bf7248e 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3014,8 +3014,8 @@ static int packet_release(struct socket *sock) synchronize_net(); + kfree(po->rollover); if (f) { - kfree(po->rollover); fanout_release_data(f); kfree(f); } |