6.6-stable review patch. If anyone has any objections, please let me know.
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From: Hyunwoo Kim v4bel@theori.io
commit 2e07e8348ea454615e268222ae3fc240421be768 upstream.
This can cause a race with bt_sock_ioctl() because bt_sock_recvmsg() gets the skb from sk->sk_receive_queue and then frees it without holding lock_sock. A use-after-free for a skb occurs with the following flow. ``` bt_sock_recvmsg() -> skb_recv_datagram() -> skb_free_datagram() bt_sock_ioctl() -> skb_peek() ``` Add lock_sock to bt_sock_recvmsg() to fix this issue.
Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Hyunwoo Kim v4bel@theori.io Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/bluetooth/af_bluetooth.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -309,11 +309,14 @@ int bt_sock_recvmsg(struct socket *sock, if (flags & MSG_OOB) return -EOPNOTSUPP;
+ lock_sock(sk); + skb = skb_recv_datagram(sk, flags, &err); if (!skb) { if (sk->sk_shutdown & RCV_SHUTDOWN) - return 0; + err = 0;
+ release_sock(sk); return err; }
@@ -343,6 +346,8 @@ int bt_sock_recvmsg(struct socket *sock,
skb_free_datagram(sk, skb);
+ release_sock(sk); + if (flags & MSG_TRUNC) copied = skblen;