From: "Lee, Chun-Yi" <joeyli.kernel@gmail.com>
To: Marcel Holtmann <marcel@holtmann.org>,
Johan Hedberg <johan.hedberg@gmail.com>
Cc: linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
Yu Hao <yhao016@ucr.edu>, "Lee, Chun-Yi" <jlee@suse.com>
Subject: [PATCH] Bluetooth: hci_ldisc: check HCI_UART_PROTO_READY flag in HCIUARTGETPROTO
Date: Mon, 10 Jul 2023 15:07:45 +0800 [thread overview]
Message-ID: <20230710070745.5505-1-jlee@suse.com> (raw)
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
https://lore.kernel.org/all/CA+UBctC3p49aTgzbVgkSZ2+TQcqq4fPDO7yZitFT5uBPDeCO2g@mail.gmail.com/
The information of C reproducer can also reference here:
https://lore.kernel.org/lkml/CA+UBctDPEvHdkHMwD340=n02rh+jNRJNNQ5LBZNA+Wm4Keh2ow@mail.gmail.com/T/
Reported-by: Weiteng Chen <wchen130@ucr.edu>
Reported-by: Yu Hao <yhao016@ucr.edu>
Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
---
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 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;
--
2.35.3
next reply other threads:[~2023-07-10 7:08 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-10 7:07 Lee, Chun-Yi [this message]
2023-07-10 7:37 ` Bluetooth: hci_ldisc: check HCI_UART_PROTO_READY flag in HCIUARTGETPROTO bluez.test.bot
-- strict thread matches above, loose matches on Subject: below --
2023-07-10 15:17 [PATCH] " Lee, Chun-Yi
2023-07-12 21:20 ` patchwork-bot+bluetooth
2023-07-14 16:08 Lee, Chun-Yi
2023-07-14 16:17 ` joeyli
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