From 0d52fb54f0cf70299d4b0f37f38a27ee1d467507 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Wed, 27 Oct 2021 10:08:18 +0200
Subject: [PATCH] ath6kl: fix division by zero in send path
commit c1b9ca365deae667192be9fe24db244919971234 upstream.
Add the missing endpoint max-packet sanity check to probe() to avoid
division by zero in ath10k_usb_hif_tx_sg() in case a malicious device
has broken descriptors (or when doing descriptor fuzz testing).
Note that USB core will reject URBs submitted for endpoints with zero
wMaxPacketSize but that drivers doing packet-size calculations still
need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip
endpoint descriptors with maxpacket=0")).
Fixes: 9cbee358687e ("ath6kl: add full USB support")
Cc: stable@vger.kernel.org # 3.5
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211027080819.6675-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/wireless/ath/ath6kl/usb.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c
index 5372e948e761d..a917092b259ce 100644
--- a/drivers/net/wireless/ath/ath6kl/usb.c
+++ b/drivers/net/wireless/ath/ath6kl/usb.c
@@ -340,6 +340,11 @@ static int ath6kl_usb_setup_pipe_resources(struct ath6kl_usb *ar_usb)
le16_to_cpu(endpoint->wMaxPacketSize),
endpoint->bInterval);
}
+
+ /* Ignore broken descriptors. */
+ if (usb_endpoint_maxp(endpoint) == 0)
+ continue;
+
urbcount = 0;
pipe_num =
--
2.30.2