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| author | Willem de Bruijn <willemb@google.com> | 2017-08-10 12:41:58 -0400 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2017-11-02 10:45:59 +0100 |
| commit | fe1fd359c1dbde1c1561802f62a16ddc67c9ac07 (patch) | |
| tree | 7351dedc6bf841afbb042dce312671eb5c388a24 | |
| parent | 162f50e6914ff75f11d15e52507aa88875878fd8 (diff) | |
| download | linux-stable-fe1fd359c1dbde1c1561802f62a16ddc67c9ac07.tar.gz linux-stable-fe1fd359c1dbde1c1561802f62a16ddc67c9ac07.zip | |
packet: fix tp_reserve race in packet_set_ring
commit c27927e372f0785f3303e8fad94b85945e2c97b7 upstream.
Updates to tp_reserve can race with reads of the field in
packet_set_ring. Avoid this by holding the socket lock during
updates in setsockopt PACKET_RESERVE.
This bug was discovered by syzkaller.
Fixes: 8913336a7e8d ("packet: add PACKET_RESERVE sockopt")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | net/packet/af_packet.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index b915d0112874..2f22b0759f2c 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3183,14 +3183,19 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv if (optlen != sizeof(val)) return -EINVAL; - if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) - return -EBUSY; if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; if (val > INT_MAX) return -EINVAL; - po->tp_reserve = val; - return 0; + lock_sock(sk); + if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { + ret = -EBUSY; + } else { + po->tp_reserve = val; + ret = 0; + } + release_sock(sk); + return ret; } case PACKET_LOSS: { |