From 290a3644609526f7ac12529cd1618042fa5a32db Mon Sep 17 00:00:00 2001 From: Chen Changcheng Date: Wed, 22 Jul 2026 16:31:36 +0800 Subject: [PATCH] Bluetooth: btrsi: Move set_bt_context after successful HCI registration In rsi_hci_attach(), ops->set_bt_context() stores the newly allocated h_adapter into common->bt_adapter before hci_alloc_dev() and hci_register_dev() are called. If either of these fails, h_adapter is freed but common->bt_adapter remains a non-NULL dangling pointer. This causes a deterministically reachable use-after-free when the device operates in a BT+WiFi coexistence mode and CONFIG_RSI_COEX is enabled. The following software-only trigger paths exist: 1. SDIO driver .remove (rsi_disconnect) 2. USB driver .disconnect (rsi_disconnect) 3. SDIO driver .shutdown (rsi_shutdown) 4. Hibernation .freeze (rsi_freeze) All four paths check: if (IS_ENABLED(CONFIG_RSI_COEX) && coex_mode > 1 && bt_adapter) rsi_bt_ops.detach(bt_adapter); // use-after-free coex_mode is set during rsi_91x_init(), before rsi_hci_attach() is called, and is not cleared on attach failure. Since set_bt_context() already wrote bt_adapter before the failure, the deinit paths see a non-NULL dangling pointer and proceed to detach it. Fix this by moving set_bt_context() after hci_register_dev() succeeds. On failure paths bt_adapter stays NULL, and the deinit callers correctly skip the detach call. Signed-off-by: Chen Changcheng Signed-off-by: Luiz Augusto von Dentz --- drivers/bluetooth/btrsi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/bluetooth/btrsi.c b/drivers/bluetooth/btrsi.c index 59ad0b9b14c3..3f802b7c83f7 100644 --- a/drivers/bluetooth/btrsi.c +++ b/drivers/bluetooth/btrsi.c @@ -107,7 +107,6 @@ static int rsi_hci_attach(void *priv, struct rsi_proto_ops *ops) return -ENOMEM; h_adapter->priv = priv; - ops->set_bt_context(priv, h_adapter); h_adapter->proto_ops = ops; hdev = hci_alloc_dev(); @@ -136,6 +135,8 @@ static int rsi_hci_attach(void *priv, struct rsi_proto_ops *ops) goto err; } + ops->set_bt_context(priv, h_adapter); + return 0; err: h_adapter->hdev = NULL;