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authorWillem de Bruijn <willemb@google.com>2019-05-31 12:37:23 -0400
committerDavid S. Miller <davem@davemloft.net>2019-06-02 18:10:14 -0700
commitafa0925c6fcc6a8f610e996ca09bc3215048033c (patch)
tree626dcaed42ebd07593d937544ee61346102ea05c /net/packet/af_packet.c
parent8c268598192df9a07ca967f6a8d5f12c3c1b3888 (diff)
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/af_packet.c')
-rw-r--r--net/packet/af_packet.c2
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);
}