diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2020-01-15 20:49:04 +0300 |
|---|---|---|
| committer | Johan Hedberg <johan.hedberg@intel.com> | 2020-01-26 10:34:17 +0200 |
| commit | 11eb85ec42dc8c7a7ec519b90ccf2eeae9409de8 (patch) | |
| tree | a88ca07a4de1b08600afabe48fb8b92b15b5cc28 /net/bluetooth/hci_sock.c | |
| parent | 18f81241b74fb49d576c83fbbab9a0b6e3bb20d4 (diff) | |
Bluetooth: Fix race condition in hci_release_sock()
Syzbot managed to trigger a use after free "KASAN: use-after-free Write
in hci_sock_bind". I have reviewed the code manually and one possibly
cause I have found is that we are not holding lock_sock(sk) when we do
the hci_dev_put(hdev) in hci_sock_release(). My theory is that the bind
and the release are racing against each other which results in this use
after free.
Reported-by: syzbot+eba992608adf3d796bcc@syzkaller.appspotmail.com
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Diffstat (limited to 'net/bluetooth/hci_sock.c')
| -rw-r--r-- | net/bluetooth/hci_sock.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index 5756b124c2cb..9c4a093f8960 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -839,6 +839,8 @@ static int hci_sock_release(struct socket *sock) if (!sk) return 0; + lock_sock(sk); + switch (hci_pi(sk)->channel) { case HCI_CHANNEL_MONITOR: atomic_dec(&monitor_promisc); @@ -886,6 +888,7 @@ static int hci_sock_release(struct socket *sock) skb_queue_purge(&sk->sk_receive_queue); skb_queue_purge(&sk->sk_write_queue); + release_sock(sk); sock_put(sk); return 0; } |