diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2020-01-15 20:49:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-05 13:05:47 +0000 |
| commit | 94fd874c64d71fbc73d9f21f9521a4ade6b7d26a (patch) | |
| tree | ce41a46f1b4f4d7669e80ad770ee8e1d766ebb77 | |
| parent | 1a270e5039adb18cb35a7e250a85b3138055319f (diff) | |
Bluetooth: Fix race condition in hci_release_sock()
commit 11eb85ec42dc8c7a7ec519b90ccf2eeae9409de8 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 ca1836941f3c..44b3146c6117 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -826,6 +826,8 @@ 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); @@ -873,6 +875,7 @@ 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; } |