Hi,
Ping for this backport.
Thanks,
Harshit
On 02/08/24 20:41, Harshit Mogalapalli wrote:
From: "Lee, Chun-Yi" <joeyli.kernel@xxxxxxxxx>
commit 9c33663af9ad115f90c076a1828129a3fbadea98 upstream.
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@xxxxxxx>
Closes: https://lore.kernel.org/all/CA+UBctC3p49aTgzbVgkSZ2+TQcqq4fPDO7yZitFT5uBPDeCO2g@xxxxxxxxxxxxxx/ [1]
Reported-by: Weiteng Chen <wchen130@xxxxxxx>
Closes: https://lore.kernel.org/lkml/CA+UBctDPEvHdkHMwD340=n02rh+jNRJNNQ5LBZNA+Wm4Keh2ow@xxxxxxxxxxxxxx/T/ [2]
Signed-off-by: "Lee, Chun-Yi" <jlee@xxxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
[Harshit: bp to stable kernels]
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
---
This is backport of a fix for CVE-2023-31083, it applies cleanly to all
stable trees and I have build tested this.
drivers/bluetooth/hci_ldisc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 865112e96ff9..c1feebd9e3a0 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -770,7 +770,8 @@ static int hci_uart_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
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;
