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authorDouglas Anderson <dianders@chromium.org>2023-06-30 15:33:14 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-07-27 08:50:47 +0200
commit0d4d6b083da9b033ddccef72d77f373c819ae3ea (patch)
tree154c2d62d5dc973f9294699cdf89583e6a5ec512
parente969bfed84c1f88dc722a678ee08488e86f0ec1a (diff)
downloadlinux-0d4d6b083da9b033ddccef72d77f373c819ae3ea.tar.gz
Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor()
[ Upstream commit de6dfcefd107667ce2dbedf4d9337f5ed557a4a1 ]

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@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--net/bluetooth/hci_core.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index be0e6865b340..d034bf2a999e 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;
 	}