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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2020-01-15 20:49:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-06 00:22:42 +0300 |
| commit | 07d00820bf987985e04a1e9abf63bc1b1aff3aa5 (patch) | |
| tree | fe18d7f2f27498a80fe05d279ffb73349785eb3f /net/bluetooth | |
| parent | f39406a925b09130b5baa53bb09d416ef64e38a7 (diff) | |
| download | linux-07d00820bf987985e04a1e9abf63bc1b1aff3aa5.tar.xz | |
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>
Diffstat (limited to 'net/bluetooth')
| -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 d32077b28433..8159b344deef 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -831,6 +831,8 @@ 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); @@ -878,6 +880,7 @@ 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; } |