From: Zachary Amsden <zach@xxxxxxxxxx> Chuck Ebbert wrote: > I think that should be "|" instead of "+". I think so too. I merely moved the code here and didn't notice it in all this excitement. 0x00cf9a000xff306600 => Present CPL-0 32-bit code segment, base 0x0000ff30, limit 0xf6601 pages, for which desc_empty(desc) is true. Thankfully, this is not used as a security check, but it can falsely overwrite TLS segments with carefully chosen base / limits. I do not believe this is an issue in practice, but it is a kernel bug. Nice catch. Looks like it affects all 2.6.X kernels. Chuck Ebbert noticed that the desc_empty macro is incorrect. Fix it. Signed-off-by: Zachary Amsden <zach@xxxxxxxxxx> Signed-off-by: Chris Wright <chrisw@xxxxxxxx> --- diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h --- a/include/asm-i386/processor.h +++ b/include/asm-i386/processor.h @@ -29,7 +29,7 @@ struct desc_struct { }; #define desc_empty(desc) \ - (!((desc)->a + (desc)->b)) + (!((desc)->a | (desc)->b)) #define desc_equal(desc1, desc2) \ (((desc1)->a == (desc2)->a) && ((desc1)->b == (desc2)->b))