[PATCH 4.14 05/22] ieee802154: atusb: fix uninit value in atusb_set_extended_addr

From: Greg Kroah-Hartman
Date: Mon Jan 10 2022 - 02:29:22 EST


From: Pavel Skripkin <paskripkin@xxxxxxxxx>

commit 754e4382354f7908923a1949d8dc8d05f82f09cb upstream.

Alexander reported a use of uninitialized value in
atusb_set_extended_addr(), that is caused by reading 0 bytes via
usb_control_msg().

Fix it by validating if the number of bytes transferred is actually
correct, since usb_control_msg() may read less bytes, than was requested
by caller.

Fail log:

BUG: KASAN: uninit-cmp in ieee802154_is_valid_extended_unicast_addr include/linux/ieee802154.h:310 [inline]
BUG: KASAN: uninit-cmp in atusb_set_extended_addr drivers/net/ieee802154/atusb.c:1000 [inline]
BUG: KASAN: uninit-cmp in atusb_probe.cold+0x29f/0x14db drivers/net/ieee802154/atusb.c:1056
Uninit value used in comparison: 311daa649a2003bd stack handle: 000000009a2003bd
ieee802154_is_valid_extended_unicast_addr include/linux/ieee802154.h:310 [inline]
atusb_set_extended_addr drivers/net/ieee802154/atusb.c:1000 [inline]
atusb_probe.cold+0x29f/0x14db drivers/net/ieee802154/atusb.c:1056
usb_probe_interface+0x314/0x7f0 drivers/usb/core/driver.c:396

Fixes: 7490b008d123 ("ieee802154: add support for atusb transceiver")
Reported-by: Alexander Potapenko <glider@xxxxxxxxxx>
Acked-by: Alexander Aring <aahringo@xxxxxxxxxx>
Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220104182806.7188-1-paskripkin@xxxxxxxxx
Signed-off-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ieee802154/atusb.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/net/ieee802154/atusb.c
+++ b/drivers/net/ieee802154/atusb.c
@@ -84,7 +84,9 @@ static int atusb_control_msg(struct atus

ret = usb_control_msg(usb_dev, pipe, request, requesttype,
value, index, data, size, timeout);
- if (ret < 0) {
+ if (ret < size) {
+ ret = ret < 0 ? ret : -ENODATA;
+
atusb->err = ret;
dev_err(&usb_dev->dev,
"atusb_control_msg: req 0x%02x val 0x%x idx 0x%x, error %d\n",
@@ -656,9 +658,9 @@ static int atusb_get_and_show_build(stru
if (!build)
return -ENOMEM;

- ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
- ATUSB_BUILD, ATUSB_REQ_FROM_DEV, 0, 0,
- build, ATUSB_BUILD_SIZE, 1000);
+ /* We cannot call atusb_control_msg() here, since this request may read various length data */
+ ret = usb_control_msg(atusb->usb_dev, usb_rcvctrlpipe(usb_dev, 0), ATUSB_BUILD,
+ ATUSB_REQ_FROM_DEV, 0, 0, build, ATUSB_BUILD_SIZE, 1000);
if (ret >= 0) {
build[ret] = 0;
dev_info(&usb_dev->dev, "Firmware: build %s\n", build);