diff options
| author | Luiz Augusto von Dentz | 2023-02-01 14:01:11 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-03-10 09:33:01 +0100 |
| commit | 64e28ecf44e46de9f01915a4146706a21c3469d2 (patch) | |
| tree | 9d30058fab6e921d39ab3fe84caffa3b9ad766e0 /net/bluetooth | |
| parent | 1913ff10fcea0ee5668d10e1d0ea27d409f5f00f (diff) | |
Bluetooth: L2CAP: Fix potential user-after-free
[ Upstream commit df5703348813235874d851934e957c3723d71644 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/l2cap_core.c | 24 | ||||
| -rw-r--r-- | net/bluetooth/l2cap_sock.c | 8 |
2 files changed, 8 insertions, 24 deletions
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 9fdede5fe71c..da85768b04b7 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -2683,14 +2683,6 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len) if (IS_ERR(skb)) return PTR_ERR(skb); - /* 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 -ENOTCONN; - } - l2cap_do_send(chan, skb); return len; } @@ -2735,14 +2727,6 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len) if (IS_ERR(skb)) return PTR_ERR(skb); - /* 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 -ENOTCONN; - } - l2cap_do_send(chan, skb); err = len; break; @@ -2763,14 +2747,6 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len) */ err = l2cap_segment_sdu(chan, &seg_queue, msg, len); - /* The channel could have been closed while segmenting, - * check that it is still connected. - */ - if (chan->state != BT_CONNECTED) { - __skb_queue_purge(&seg_queue); - err = -ENOTCONN; - } - if (err) break; 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; |