diff options
| author | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2023-02-02 01:01:11 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-11 18:31:37 +0300 |
| commit | a6a7d1541fefddf7ca0cfb34c1bff63ff809cc49 (patch) | |
| tree | 1211c8470c800063b4ac039fedcb9156e87563c6 /net/bluetooth/l2cap_sock.c | |
| parent | 4545d7a70ce0fc78b1d3c33c4a0939a86f363b57 (diff) | |
| download | linux-a6a7d1541fefddf7ca0cfb34c1bff63ff809cc49.tar.xz | |
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/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 d938311c58a8..1c6d01a27e0e 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1414,6 +1414,14 @@ 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; |