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Bluetooth: hci_ldisc: check HCI_UART_PROTO_READY flag in HCIUARTGETPROTO

Message ID 20230710151723.15617-1-jlee@suse.com
State Superseded
Headers show
Series Bluetooth: hci_ldisc: check HCI_UART_PROTO_READY flag in HCIUARTGETPROTO | expand

Commit Message

Lee, Chun-Yi July 10, 2023, 3:17 p.m. UTC
This patch adds code to check HCI_UART_PROTO_READY flag before
accessing hci_uart->proto. It fixs 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>
---
 drivers/bluetooth/hci_ldisc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

patchwork-bot+bluetooth@kernel.org July 12, 2023, 9:20 p.m. UTC | #1
Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Mon, 10 Jul 2023 23:17:23 +0800 you wrote:
> This patch adds code to check HCI_UART_PROTO_READY flag before
> accessing hci_uart->proto. It fixs 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]
> 
> [...]

Here is the summary with links:
  - Bluetooth: hci_ldisc: check HCI_UART_PROTO_READY flag in HCIUARTGETPROTO
    https://git.kernel.org/bluetooth/bluetooth-next/c/ff1b86784849

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index efdda2c3fce8..a76eb98c0047 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;