From: Prashant Malani Date: Sat, 24 Aug 2019 08:36:19 +0000 (-0700) Subject: r8152: Set memory to all 0xFFs on failed reg reads X-Git-Tag: v6.6-pxa1908~11024^2 X-Git-Url: https://git.dujemihanovic.xyz/?a=commitdiff_plain;h=f53a7ad18959;p=linux.git r8152: Set memory to all 0xFFs on failed reg reads get_registers() blindly copies the memory written to by the usb_control_msg() call even if the underlying urb failed. This could lead to junk register values being read by the driver, since some indirect callers of get_registers() ignore the return values. One example is: ocp_read_dword() ignores the return value of generic_ocp_read(), which calls get_registers(). So, emulate PCI "Master Abort" behavior by setting the buffer to all 0xFFs when usb_control_msg() fails. This patch is copied from the r8152 driver (v2.12.0) published by Realtek (www.realtek.com). Signed-off-by: Prashant Malani Acked-by: Hayes Wang Signed-off-by: David S. Miller --- diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index 0cc03a9ff545..eee0f5007ee3 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -799,8 +799,11 @@ int get_registers(struct r8152 *tp, u16 value, u16 index, u16 size, void *data) ret = usb_control_msg(tp->udev, usb_rcvctrlpipe(tp->udev, 0), RTL8152_REQ_GET_REGS, RTL8152_REQT_READ, value, index, tmp, size, 500); + if (ret < 0) + memset(data, 0xff, size); + else + memcpy(data, tmp, size); - memcpy(data, tmp, size); kfree(tmp); return ret;