From: "Lee, Chun-Yi" <joeyli.kernel@gmail.com>
Date: Mon, 10 Jul 2023 23:17:23 +0800
Subject: Bluetooth: hci_ldisc: check HCI_UART_PROTO_READY flag in
HCIUARTGETPROTO
Patch-mainline: v6.6-rc1
Git-commit: 9c33663af9ad115f90c076a1828129a3fbadea98
References: bsc#1210780 CVE-2023-31083
This patch adds code to check HCI_UART_PROTO_READY flag before
accessing hci_uart->proto. It fixes the race condition in
hci_uart_tty_ioctl() between HCIUARTSETPROTO and HCIUARTGETPROTO.
This issue bug found by Yu Hao and Weiteng Chen:
BUG: general protection fault in hci_uart_tty_ioctl [1]
The information of C reproducer can also reference the link [2]
Reported-by: Yu Hao <yhao016@ucr.edu>
Closes: https://lore.kernel.org/all/CA+UBctC3p49aTgzbVgkSZ2+TQcqq4fPDO7yZitFT5uBPDeCO2g@mail.gmail.com/ [1]
Reported-by: Weiteng Chen <wchen130@ucr.edu>
Closes: https://lore.kernel.org/lkml/CA+UBctDPEvHdkHMwD340=n02rh+jNRJNNQ5LBZNA+Wm4Keh2ow@mail.gmail.com/T/ [2]
Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
drivers/bluetooth/hci_ldisc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -759,7 +759,8 @@ static int hci_uart_tty_ioctl(struct tty
break;
case HCIUARTGETPROTO:
- if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
+ if (test_bit(HCI_UART_PROTO_SET, &hu->flags) &&
+ test_bit(HCI_UART_PROTO_READY, &hu->flags))
err = hu->proto->id;
else
err = -EUNATCH;