diff mbox series

Bluetooth: fix division by zero in send path

Message ID 20211025113944.4350-1-johan@kernel.org (mailing list archive)
State Accepted
Delegated to: Marcel Holtmann
Headers show
Series Bluetooth: fix division by zero in send path | expand

Checks

Context Check Description
tedd_an/checkpatch success Checkpatch PASS
tedd_an/gitlint success Gitlint PASS
tedd_an/buildkernel success Build Kernel PASS
tedd_an/testrunnersetup success Test Runner Setup PASS
tedd_an/testrunnerl2cap-tester success Total: 40, Passed: 40 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunnerbnep-tester success Total: 1, Passed: 1 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunnermgmt-tester fail Total: 468, Passed: 463 (98.9%), Failed: 5, Not Run: 0
tedd_an/testrunnerrfcomm-tester success Total: 9, Passed: 9 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunnersco-tester success Total: 12, Passed: 12 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunnersmp-tester success Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
tedd_an/testrunneruserchan-tester success Total: 4, Passed: 4 (100.0%), Failed: 0, Not Run: 0

Commit Message

Johan Hovold Oct. 25, 2021, 11:39 a.m. UTC 
Add the missing bulk-out endpoint sanity check to probe() to avoid
division by zero in bfusb_send_frame() 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")).

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/bluetooth/bfusb.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Marcel Holtmann Oct. 25, 2021, 1:05 p.m. UTC | #1 
Hi Johan,

> Add the missing bulk-out endpoint sanity check to probe() to avoid
> division by zero in bfusb_send_frame() 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")).
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/bluetooth/bfusb.c | 2 ++
> 1 file changed, 2 insertions(+)

patch has been applied to bluetooth-next tree.

Regards

Marcel
diff mbox series

Patch

diff --git a/drivers/bluetooth/bfusb.c b/drivers/bluetooth/bfusb.c
index 5a321b4076aa..df80fb324356 100644
--- a/drivers/bluetooth/bfusb.c
+++ b/drivers/bluetooth/bfusb.c
@@ -627,6 +627,8 @@  static int bfusb_probe(struct usb_interface *intf, const struct usb_device_id *i
 	data->bulk_in_ep    = bulk_in_ep->desc.bEndpointAddress;
 	data->bulk_out_ep   = bulk_out_ep->desc.bEndpointAddress;
 	data->bulk_pkt_size = le16_to_cpu(bulk_out_ep->desc.wMaxPacketSize);
+	if (!data->bulk_pkt_size)
+		goto done;
 
 	rwlock_init(&data->lock);