2021-06-07 16:22:19

by Sasha Levin

[permalink] [raw]
Subject: [PATCH AUTOSEL 4.19 10/21] Bluetooth: use correct lock to prevent UAF of hdev object

From: Lin Ma <[email protected]>

[ Upstream commit e305509e678b3a4af2b3cfd410f409f7cdaabb52 ]

The hci_sock_dev_event() function will cleanup the hdev object for
sockets even if this object may still be in used within the
hci_sock_bound_ioctl() function, result in UAF vulnerability.

This patch replace the BH context lock to serialize these affairs
and prevent the race condition.

Signed-off-by: Lin Ma <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
net/bluetooth/hci_sock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index e506c51ff765..06156de24c50 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -755,7 +755,7 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event)
/* Detach sockets from device */
read_lock(&hci_sk_list.lock);
sk_for_each(sk, &hci_sk_list.head) {
- bh_lock_sock_nested(sk);
+ lock_sock(sk);
if (hci_pi(sk)->hdev == hdev) {
hci_pi(sk)->hdev = NULL;
sk->sk_err = EPIPE;
@@ -764,7 +764,7 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event)

hci_dev_put(hdev);
}
- bh_unlock_sock(sk);
+ release_sock(sk);
}
read_unlock(&hci_sk_list.lock);
}
--
2.30.2