| Message ID | 20230630153315.v3.1.I3b7c8905728f3124576361ca35ed28e37f12f5d1@changeid |
|---|---|
| State | Accepted |
| Commit | 2648c5eb33ca23665bf97153075bce7371434605 |
| Headers | show |
| Series | [v3,1/2] Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor() | expand |
Hello: This series was applied to bluetooth/bluetooth-next.git (master) by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>: On Fri, 30 Jun 2023 15:33:14 -0700 you wrote: > 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() > > [...] Here is the summary with links: - [v3,1/2] Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor() https://git.kernel.org/bluetooth/bluetooth-next/c/2648c5eb33ca - [v3,2/2] Bluetooth: hci_sync: Don't double print name in add/remove adv_monitor https://git.kernel.org/bluetooth/bluetooth-next/c/22d2055a576d You are awesome, thank you!
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; }
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> --- Changes in v3: - Back to v1 where we stash the handle in a local. Changes in v2: - Move the print, don't stash handle in a local. net/bluetooth/hci_core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)