[Linux-kernel-mentees] [PATCH 2/2] net/bluetooth: Prevent out-of-bounds read in hci_inquiry_result_with_rssi_evt()

From: Peilin Ye
Date: Fri Jul 10 2020 - 17:47:27 EST


Check `num_rsp` before using it as for-loop counter. Add `unlock` label.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Peilin Ye <yepeilin.cs@xxxxxxxxx>
---
net/bluetooth/hci_event.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 8b3736c83b8e..f9f4262414b3 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4159,6 +4159,9 @@ static void hci_inquiry_result_with_rssi_evt(struct hci_dev *hdev,
struct inquiry_info_with_rssi_and_pscan_mode *info;
info = (void *) (skb->data + 1);

+ if (skb->len < num_rsp * sizeof(*info) + 1)
+ goto unlock;
+
for (; num_rsp; num_rsp--, info++) {
u32 flags;

@@ -4180,6 +4183,9 @@ static void hci_inquiry_result_with_rssi_evt(struct hci_dev *hdev,
} else {
struct inquiry_info_with_rssi *info = (void *) (skb->data + 1);

+ if (skb->len < num_rsp * sizeof(*info) + 1)
+ goto unlock;
+
for (; num_rsp; num_rsp--, info++) {
u32 flags;

@@ -4200,6 +4206,7 @@ static void hci_inquiry_result_with_rssi_evt(struct hci_dev *hdev,
}
}

+unlock:
hci_dev_unlock(hdev);
}

--
2.25.1