From bda93eec78cdbfe5cda00785cefebd443e56b88b Mon Sep 17 00:00:00 2001 From: Keenan Dong Date: Wed, 1 Apr 2026 22:25:26 +0800 Subject: [PATCH] Bluetooth: MGMT: validate mesh send advertising payload length mesh_send() currently bounds MGMT_OP_MESH_SEND by total command length, but it never verifies that the bytes supplied for the flexible adv_data[] array actually match the embedded adv_data_len field. MGMT_MESH_SEND_SIZE only covers the fixed header, so a truncated command can still pass the existing 20..50 byte range check and later drive the async mesh send path past the end of the queued command buffer. Keep rejecting zero-length and oversized advertising payloads, but validate adv_data_len explicitly and require the command length to exactly match the flexible array size before queueing the request. Fixes: b338d91703fa ("Bluetooth: Implement support for Mesh") Reported-by: Keenan Dong Signed-off-by: Keenan Dong Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/mgmt.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index adcd86c15b4e..b05bb380e5f8 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -2478,6 +2478,7 @@ static int mesh_send(struct sock *sk, struct hci_dev *hdev, void *data, u16 len) struct mgmt_mesh_tx *mesh_tx; struct mgmt_cp_mesh_send *send = data; struct mgmt_rp_mesh_read_features rp; + u16 expected_len; bool sending; int err = 0; @@ -2485,12 +2486,19 @@ static int mesh_send(struct sock *sk, struct hci_dev *hdev, void *data, u16 len) !hci_dev_test_flag(hdev, HCI_MESH_EXPERIMENTAL)) return mgmt_cmd_status(sk, hdev->id, MGMT_OP_MESH_SEND, MGMT_STATUS_NOT_SUPPORTED); - if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED) || - len <= MGMT_MESH_SEND_SIZE || - len > (MGMT_MESH_SEND_SIZE + 31)) + if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) return mgmt_cmd_status(sk, hdev->id, MGMT_OP_MESH_SEND, MGMT_STATUS_REJECTED); + if (!send->adv_data_len || send->adv_data_len > 31) + return mgmt_cmd_status(sk, hdev->id, MGMT_OP_MESH_SEND, + MGMT_STATUS_REJECTED); + + expected_len = struct_size(send, adv_data, send->adv_data_len); + if (expected_len != len) + return mgmt_cmd_status(sk, hdev->id, MGMT_OP_MESH_SEND, + MGMT_STATUS_INVALID_PARAMS); + hci_dev_lock(hdev); memset(&rp, 0, sizeof(rp));