[PATCH] Bluetooth: refactor malicious adv data check
From: Brian Gix <hidden>
Date: 2021-11-24 18:50:50
Subsystem:
bluetooth subsystem, the rest · Maintainers:
Marcel Holtmann, Luiz Augusto von Dentz, Linus Torvalds
Check for out-of-bound read was being performed at the end of while num_reports loop, and would fill journal with false positives. Added check to beginning of loop processing so that it doesn't get checked after ptr has been advanced. Signed-off-by: Brian Gix <redacted> --- net/bluetooth/hci_event.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index efc5458b1345..7017805fb698 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c@@ -5920,6 +5920,11 @@ static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) struct hci_ev_le_advertising_info *ev = ptr; s8 rssi; + if (ptr > (void *) skb_tail_pointer(skb) - sizeof(*ev)) { + bt_dev_err(hdev, "Malicious advertising data."); + break; + } + if (ev->length <= HCI_MAX_AD_LENGTH && ev->data + ev->length <= skb_tail_pointer(skb)) { rssi = ev->data[ev->length];
@@ -5931,11 +5936,6 @@ static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) } ptr += sizeof(*ev) + ev->length + 1; - - if (ptr > (void *) skb_tail_pointer(skb) - sizeof(*ev)) { - bt_dev_err(hdev, "Malicious advertising data. Stopping processing"); - break; - } } hci_dev_unlock(hdev);
--
2.31.1