diff options
| author | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2023-02-01 14:01:11 -0800 |
|---|---|---|
| committer | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2023-02-09 14:18:48 -0800 |
| commit | df5703348813235874d851934e957c3723d71644 (patch) | |
| tree | aa8217ebec403131c1524a365c6ac6e70fe71302 /net/bluetooth/l2cap_sock.c | |
| parent | 2394186a2cefb9a45a029281a55749804dd8c556 (diff) | |
Bluetooth: L2CAP: Fix potential user-after-free
This fixes all instances of which requires to allocate a buffer calling
alloc_skb which may release the chan lock and reacquire later which
makes it possible that the chan is disconnected in the meantime.
Fixes: a6a5568c03c4 ("Bluetooth: Lock the L2CAP channel when sending")
Reported-by: Alexander Coffin <alex.coffin@matician.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Diffstat (limited to 'net/bluetooth/l2cap_sock.c')
| -rw-r--r-- | net/bluetooth/l2cap_sock.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index ca8f07f3542b..eebe256104bc 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1624,6 +1624,14 @@ static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan, if (!skb) return ERR_PTR(err); + /* Channel lock is released before requesting new skb and then + * reacquired thus we need to recheck channel state. + */ + if (chan->state != BT_CONNECTED) { + kfree_skb(skb); + return ERR_PTR(-ENOTCONN); + } + skb->priority = sk->sk_priority; bt_cb(skb)->l2cap.chan = chan; |