From: Zihan Xi Date: Tue, 21 Jul 2026 14:36:07 +0000 (+0800) Subject: Bluetooth: mgmt: fix UAF in pair command cancellation X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d0a7b48ad0921bd88effaee10bf970ab1d5d0ddd;p=thirdparty%2Fkernel%2Fstable.git Bluetooth: mgmt: fix UAF in pair command cancellation The pairing completion and authentication failure callbacks look up the pending MGMT_OP_PAIR_DEVICE command by walking hdev->mgmt_pending. The lookup returned a command that was still linked on the shared pending list, without keeping mgmt_pending_lock held for the later dereference and removal. A concurrent MGMT_OP_CANCEL_PAIR_DEVICE request can remove and free the same pending command before the callback uses it. The reverse race is also possible when cancel_pair_device() gets a command from pending_find() and a callback removes it before the cancel path dereferences it. This can lead to a use-after-free and a second list_del(). Make the pairing lookup helpers transfer ownership of the pending command by removing it from hdev->mgmt_pending while holding mgmt_pending_lock. The callbacks and cancel path then complete the command and free it directly, so racing paths cannot find or free the same command again. Take a temporary hci_conn reference in cancel_pair_device() because the command completion drops the reference stored in the pending command. Fixes: e9a416b5ce0c ("Bluetooth: Add mgmt_pair_device command") Cc: stable@vger.kernel.org Reported-by: Vega Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi Reviewed-by: Ren Wei Reported-by: Vega Signed-off-by: Luiz Augusto von Dentz --- diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 1db10e0f617f..4fd37ac79986 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -3514,11 +3514,13 @@ static int set_io_capability(struct sock *sk, struct hci_dev *hdev, void *data, NULL, 0); } -static struct mgmt_pending_cmd *find_pairing(struct hci_conn *conn) +static struct mgmt_pending_cmd *remove_pairing(struct hci_conn *conn) { struct hci_dev *hdev = conn->hdev; struct mgmt_pending_cmd *cmd; + mutex_lock(&hdev->mgmt_pending_lock); + list_for_each_entry(cmd, &hdev->mgmt_pending, list) { if (cmd->opcode != MGMT_OP_PAIR_DEVICE) continue; @@ -3526,9 +3528,39 @@ static struct mgmt_pending_cmd *find_pairing(struct hci_conn *conn) if (cmd->user_data != conn) continue; + list_del(&cmd->list); + mutex_unlock(&hdev->mgmt_pending_lock); return cmd; } + mutex_unlock(&hdev->mgmt_pending_lock); + + return NULL; +} + +static struct mgmt_pending_cmd *remove_pairing_by_addr(struct hci_dev *hdev, + bdaddr_t *bdaddr) +{ + struct mgmt_pending_cmd *cmd; + struct hci_conn *conn; + + mutex_lock(&hdev->mgmt_pending_lock); + + list_for_each_entry(cmd, &hdev->mgmt_pending, list) { + if (cmd->opcode != MGMT_OP_PAIR_DEVICE) + continue; + + conn = cmd->user_data; + if (bacmp(bdaddr, &conn->dst) != 0) + continue; + + list_del(&cmd->list); + mutex_unlock(&hdev->mgmt_pending_lock); + return cmd; + } + + mutex_unlock(&hdev->mgmt_pending_lock); + return NULL; } @@ -3566,10 +3598,10 @@ void mgmt_smp_complete(struct hci_conn *conn, bool complete) u8 status = complete ? MGMT_STATUS_SUCCESS : MGMT_STATUS_FAILED; struct mgmt_pending_cmd *cmd; - cmd = find_pairing(conn); + cmd = remove_pairing(conn); if (cmd) { cmd->cmd_complete(cmd, status); - mgmt_pending_remove(cmd); + mgmt_pending_free(cmd); } } @@ -3579,14 +3611,14 @@ static void pairing_complete_cb(struct hci_conn *conn, u8 status) BT_DBG("status %u", status); - cmd = find_pairing(conn); + cmd = remove_pairing(conn); if (!cmd) { BT_DBG("Unable to find a pending command"); return; } cmd->cmd_complete(cmd, mgmt_status(status)); - mgmt_pending_remove(cmd); + mgmt_pending_free(cmd); } static void le_pairing_complete_cb(struct hci_conn *conn, u8 status) @@ -3598,14 +3630,14 @@ static void le_pairing_complete_cb(struct hci_conn *conn, u8 status) if (!status) return; - cmd = find_pairing(conn); + cmd = remove_pairing(conn); if (!cmd) { BT_DBG("Unable to find a pending command"); return; } cmd->cmd_complete(cmd, mgmt_status(status)); - mgmt_pending_remove(cmd); + mgmt_pending_free(cmd); } static int pair_device(struct sock *sk, struct hci_dev *hdev, void *data, @@ -3762,23 +3794,17 @@ static int cancel_pair_device(struct sock *sk, struct hci_dev *hdev, void *data, goto unlock; } - cmd = pending_find(MGMT_OP_PAIR_DEVICE, hdev); + cmd = remove_pairing_by_addr(hdev, &addr->bdaddr); if (!cmd) { err = mgmt_cmd_status(sk, hdev->id, MGMT_OP_CANCEL_PAIR_DEVICE, MGMT_STATUS_INVALID_PARAMS); goto unlock; } - conn = cmd->user_data; - - if (bacmp(&addr->bdaddr, &conn->dst) != 0) { - err = mgmt_cmd_status(sk, hdev->id, MGMT_OP_CANCEL_PAIR_DEVICE, - MGMT_STATUS_INVALID_PARAMS); - goto unlock; - } + conn = hci_conn_get(cmd->user_data); cmd->cmd_complete(cmd, MGMT_STATUS_CANCELLED); - mgmt_pending_remove(cmd); + mgmt_pending_free(cmd); err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_CANCEL_PAIR_DEVICE, 0, addr, sizeof(*addr)); @@ -3796,6 +3822,8 @@ static int cancel_pair_device(struct sock *sk, struct hci_dev *hdev, void *data, if (conn->conn_reason == CONN_REASON_PAIR_DEVICE) hci_abort_conn(conn, HCI_ERROR_REMOTE_USER_TERM); + hci_conn_put(conn); + unlock: hci_dev_unlock(hdev); return err; @@ -10137,14 +10165,14 @@ void mgmt_auth_failed(struct hci_conn *conn, u8 hci_status) ev.addr.type = link_to_bdaddr(conn->type, conn->dst_type); ev.status = status; - cmd = find_pairing(conn); + cmd = remove_pairing(conn); mgmt_event(MGMT_EV_AUTH_FAILED, conn->hdev, &ev, sizeof(ev), cmd ? cmd->sk : NULL); if (cmd) { cmd->cmd_complete(cmd, status); - mgmt_pending_remove(cmd); + mgmt_pending_free(cmd); } }