Re: [PATCH] thunderbolt: Fix some right shifting to zero bugs

From: Mika Westerberg
Date: Fri Oct 13 2017 - 07:46:38 EST


On Fri, Oct 13, 2017 at 02:29:59PM +0300, Dan Carpenter wrote:
> The problematic code looks like this:
>
> res_seq = res_hdr->xd_hdr.length_sn & TB_XDOMAIN_SN_MASK;
> res_seq >>= TB_XDOMAIN_SN_SHIFT;
>
> TB_XDOMAIN_SN_SHIFT is 27, and right shifting a u8 27 bits is always
> going to result in zero. The fix is to declare these variables as u32.
>
> Fixes: d1ff70241a27 ("thunderbolt: Add support for XDomain discovery protocol")

I think this requires two patches as the drivers/net/thunderbolt.c is
added by another commit.

Also please CC netdev@xxxxxxxxxxxxxxx and David Miller as the patches
are in his net-next tree.

The fixes themselves look good, though.