linux-kernel - [PATCH] Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 30 Jun 2023 14:31:27 -0700
From:   Douglas Anderson <dianders@...omium.org>
To:     Marcel Holtmann <marcel@...tmann.org>,
        Johan Hedberg <johan.hedberg@...il.com>,
        Luiz Augusto von Dentz <luiz.dentz@...il.com>
Cc:     Stephen Boyd <swboyd@...omium.org>,
        Douglas Anderson <dianders@...omium.org>,
        Manish Mandlik <mmandlik@...gle.com>,
        Miao-chen Chou <mcchou@...gle.com>,
        linux-bluetooth@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor()

KASAN reports that there's a use-after-free in
hci_remove_adv_monitor(). Trawling through the disassembly, you can
see that the complaint is from the access in bt_dev_dbg() under the
HCI_ADV_MONITOR_EXT_MSFT case. The problem case happens because
msft_remove_monitor() can end up freeing the monitor
structure. Specifically:
  hci_remove_adv_monitor() ->
  msft_remove_monitor() ->
  msft_remove_monitor_sync() ->
  msft_le_cancel_monitor_advertisement_cb() ->
  hci_free_adv_monitor()

Let's fix the problem by just stashing the relevant data when it's
still valid.

Fixes: 7cf5c2978f23 ("Bluetooth: hci_sync: Refactor remove Adv Monitor")
Signed-off-by: Douglas Anderson <dianders@...omium.org>
---

 net/bluetooth/hci_core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 48917c68358d..dbb2043a9112 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1972,6 +1972,7 @@ static int hci_remove_adv_monitor(struct hci_dev *hdev,
 				  struct adv_monitor *monitor)
 {
 	int status = 0;
+	int handle;
 
 	switch (hci_get_adv_monitor_offload_ext(hdev)) {
 	case HCI_ADV_MONITOR_EXT_NONE: /* also goes here when powered off */
@@ -1980,9 +1981,10 @@ static int hci_remove_adv_monitor(struct hci_dev *hdev,
 		goto free_monitor;
 
 	case HCI_ADV_MONITOR_EXT_MSFT:
+		handle = monitor->handle;
 		status = msft_remove_monitor(hdev, monitor);
 		bt_dev_dbg(hdev, "%s remove monitor %d msft status %d",
-			   hdev->name, monitor->handle, status);
+			   hdev->name, handle, status);
 		break;
 	}
 
-- 
2.41.0.255.g8b1d071c50-goog