[PATCH 6.6 050/160] Bluetooth: MGMT: validate mesh send advertising payload length

Greg Kroah-Hartman
2026-04-08T18:22:31Z

From: Keenan Dong <keenanat2000@gmail.com>

[ Upstream commit bda93eec78cdbfe5cda00785cefebd443e56b88b ]

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 <keenanat2000@gmail.com>
Signed-off-by: Keenan Dong <keenanat2000@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 81651f8ed03d0..51a6ad6a36c8d 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -2388,6 +2388,7 @@ 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;

@@ -2395,12 +2396,19 @@ 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));
--
2.53.0