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);