[PATCH 4.2.y-ckt 105/218] Bluetooth: Fix potential buffer overflow with Add Advertising

[Kamal Mostafa]

4.2.8-ckt7 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Johan Hedberg <johan.hedberg at intel.com>

commit 6a0e78072c2ae7b20b14e0249d8108441ea928d2 upstream.

The Add Advertising command handler does the appropriate checks for
the AD and Scan Response data, however fails to take into account the
general length of the mgmt command itself, which could lead to
potential buffer overflows. This patch adds the necessary check that
the mgmt command length is consistent with the given ad and scan_rsp
lengths.

Signed-off-by: Johan Hedberg <johan.hedberg at intel.com>
Signed-off-by: Marcel Holtmann <marcel at holtmann.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/bluetooth/mgmt.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index e32a9e4..3750b37 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -7135,6 +7135,10 @@ static int add_advertising(struct sock *sk, struct hci_dev *hdev,
 		return mgmt_cmd_status(sk, hdev->id, MGMT_OP_ADD_ADVERTISING,
 				       status);
 
+	if (data_len != sizeof(*cp) + cp->adv_data_len + cp->scan_rsp_len)
+		return mgmt_cmd_status(sk, hdev->id, MGMT_OP_ADD_ADVERTISING,
+				       MGMT_STATUS_INVALID_PARAMS);
+
 	flags = __le32_to_cpu(cp->flags);
 	timeout = __le16_to_cpu(cp->timeout);
 	duration = __le16_to_cpu(cp->duration);
-- 
2.7.4