Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.18 092/136] rndis_wlan: potential buffer overflow in rndis_wlan_auth_indication() | Date | Mon, 17 Sep 2018 03:01:10 +0000 |
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From: Dan Carpenter <dan.carpenter@oracle.com>
[ Upstream commit ae636fb1554833ee5133ca47bf4b2791b6739c52 ]
This is a static checker fix, not something I have tested. The issue is that on the second iteration through the loop, we jump forward by le32_to_cpu(auth_req->length) bytes. The problem is that if the length is more than "buflen" then we end up with a negative "buflen". A negative buflen is type promoted to a high positive value and the loop continues but it's accessing beyond the end of the buffer.
I believe the "auth_req->length" comes from the firmware and if the firmware is malicious or buggy, you're already toasted so the impact of this bug is probably not very severe.
Fixes: 030645aceb3d ("rndis_wlan: handle 802.11 indications from device") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> --- drivers/net/wireless/rndis_wlan.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/net/wireless/rndis_wlan.c b/drivers/net/wireless/rndis_wlan.c index 9935bd09db1f..d4947e3a909e 100644 --- a/drivers/net/wireless/rndis_wlan.c +++ b/drivers/net/wireless/rndis_wlan.c @@ -2928,6 +2928,8 @@ static void rndis_wlan_auth_indication(struct usbnet *usbdev, while (buflen >= sizeof(*auth_req)) { auth_req = (void *)buf; + if (buflen < le32_to_cpu(auth_req->length)) + return; type = "unknown"; flags = le32_to_cpu(auth_req->flags); pairwise_error = false; -- 2.17.1
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