Bluetooth: hci_uart: fix GPF in h5_recv

[ Upstream commit 2fc7acb69fa3573d4bf7a90c323296d840daf330 ]

Syzbot hit general protection fault in h5_recv(). The problem was in
missing NULL check.

hu->serdev can be NULL and we cannot blindly pass &serdev->dev
somewhere, since it can cause GPF.

Fixes: d9dd833cf6d2 ("Bluetooth: hci_h5: Add runtime suspend")
Reported-and-tested-by: syzbot+7d41312fe3f123a6f605@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
index 0c0dede..eb0099a 100644 (file)
--- a/drivers/bluetooth/hci_h5.c
+++ b/drivers/bluetooth/hci_h5.c
@@ -587,9 +587,11 @@ static int h5_recv(struct hci_uart *hu, const void *data, int count)
                count -= processed;
        }
 
-       pm_runtime_get(&hu->serdev->dev);
-       pm_runtime_mark_last_busy(&hu->serdev->dev);
-       pm_runtime_put_autosuspend(&hu->serdev->dev);
+       if (hu->serdev) {
+               pm_runtime_get(&hu->serdev->dev);
+               pm_runtime_mark_last_busy(&hu->serdev->dev);
+               pm_runtime_put_autosuspend(&hu->serdev->dev);
+       }
 
        return 0;
 }