diff options
| author | Takashi Iwai <tiwai@suse.de> | 2021-08-28 19:18:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 16:03:52 +0300 |
| commit | 4dfba42604f08a505f1a1efc69ec5207ea6243de (patch) | |
| tree | 93f8d0cee7238a99c826cc9d391b232c096f4b15 /net/bluetooth | |
| parent | 509ae4a4f0745bff108723e5d9a61b1113ea89fe (diff) | |
| download | linux-4dfba42604f08a505f1a1efc69ec5207ea6243de.tar.xz | |
Bluetooth: sco: Fix lock_sock() blockage by memcpy_from_msg()
[ Upstream commit 99c23da0eed4fd20cae8243f2b51e10e66aa0951 ]
The sco_send_frame() also takes lock_sock() during memcpy_from_msg()
call that may be endlessly blocked by a task with userfaultd
technique, and this will result in a hung task watchdog trigger.
Just like the similar fix for hci_sock_sendmsg() in commit
92c685dc5de0 ("Bluetooth: reorganize functions..."), this patch moves
the memcpy_from_msg() out of lock_sock() for addressing the hang.
This should be the last piece for fixing CVE-2021-3640 after a few
already queued fixes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/sco.c | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index 7c24a9acbc45..93df269a6470 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -281,7 +281,8 @@ static int sco_connect(struct hci_dev *hdev, struct sock *sk) return err; } -static int sco_send_frame(struct sock *sk, struct msghdr *msg, int len) +static int sco_send_frame(struct sock *sk, void *buf, int len, + unsigned int msg_flags) { struct sco_conn *conn = sco_pi(sk)->conn; struct sk_buff *skb; @@ -293,15 +294,11 @@ static int sco_send_frame(struct sock *sk, struct msghdr *msg, int len) BT_DBG("sk %p len %d", sk, len); - skb = bt_skb_send_alloc(sk, len, msg->msg_flags & MSG_DONTWAIT, &err); + skb = bt_skb_send_alloc(sk, len, msg_flags & MSG_DONTWAIT, &err); if (!skb) return err; - if (memcpy_from_msg(skb_put(skb, len), msg, len)) { - kfree_skb(skb); - return -EFAULT; - } - + memcpy(skb_put(skb, len), buf, len); hci_send_sco(conn->hcon, skb); return len; @@ -726,6 +723,7 @@ static int sco_sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; + void *buf; int err; BT_DBG("sock %p, sk %p", sock, sk); @@ -737,14 +735,24 @@ static int sco_sock_sendmsg(struct socket *sock, struct msghdr *msg, if (msg->msg_flags & MSG_OOB) return -EOPNOTSUPP; + buf = kmalloc(len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (memcpy_from_msg(buf, msg, len)) { + kfree(buf); + return -EFAULT; + } + lock_sock(sk); if (sk->sk_state == BT_CONNECTED) - err = sco_send_frame(sk, msg, len); + err = sco_send_frame(sk, buf, len, msg->msg_flags); else err = -ENOTCONN; release_sock(sk); + kfree(buf); return err; } |