6 ms·

After reading through the original Qualys discussion[1] of this new vuln I was definitely left with a feeling that this class of bugs has not yet exhausted its

After reading through the original Qualys discussion[1] of this new vuln I was definitely left with a feeling that this class of bugs has not yet exhausted its treasure trove of vulns. This article only confirms it. Very interesting discussion that will likely continue as more people wrap their heads around this tough problem. [1] https://blog.qualys.com/securitylabs/2017/06/19/the-stack-clash https://blog.qualys.com/securitylabs/2017/06/19/the-stack-cl...

IshKebab 9y ago
Is it that tough? Everything says Windows/MSVC isn't affected.
- mnarayan01 9y ago
  Yes. I believe Windows requires you to specify a maximum reserved stack size in the program executable. That's...not going to happen for e.g. Linux.
  - smhenderson 9y ago
    That's correct and any of the various MS runtime libraries simply set it by default if you didn't. Thus this error[1] (in C) and this[2] (in VB). I remember these from pre-dotNet days but based on the second link it looks not much has changed in VB.net. [1]https://msdn.microsoft.com/en-us/library/aa264523(v=vs.60).aspx https://msdn.microsoft.com/en-us/library/aa264523(v=vs.60).a... [2]https://docs.microsoft.com/en-us/dotnet/visual-basic/language-reference/error-messages/out-of-stack-space https://docs.microsoft.com/en-us/dotnet/visual-basic/languag...
  - clarry 9y ago
    The reservation is not particularly relevant though.
  - IshKebab 9y ago
    So how does it detect stack overflows past that limit? Edit: Looks like a fix for LLVM being proposed (https://reviews.llvm.org/D9653 https://reviews.llvm.org/D9653) is just to probe every page that a stack allocation covers, rather than just the final one. Doesn't sound tough at all.
daveguy 9y ago
So the title should read "is not closed"? The parenthesis are just annoying. It's one or the other, just state it! Readers shouldn't have to solve a puzzle to read a title.
- sdrothrock 9y ago
  First read to me as someone who hadn't read the article was "someone found an ancient kernel hole and declared it closed, but in truth it's actually not," which actually seems to be what was intended... it's a fairly common use of "(not)."
- nullc 9y ago
  The title is a play on a 2010 LWN headline. This is explained in the article. But reading the article has never been a barrier for HN editing a headline to make it less accurate in the past, so why start now? :)
- CaliforniaKarl 9y ago
  I'm sorry, I'm really confused now. Here's the title of the article: An Ancient Kernel Hole is (Not) Closed I thought that I copy-pasted the article title to be the title of this submission. Did I omit the parenthesis? If so, it was unintentional, and I apologize.
  - enzanki_ars 9y ago
    HN automatically removes certain punctuation from post titles. In a lot of cases though, it creates more confusion. Definitely not your fault.
    - CaliforniaKarl 9y ago
      I did not know that! I'm tempted to experiment now 8-) Thanks for the heads-up!

IshKebab 9y ago

Is it that tough? Everything says Windows/MSVC isn't affected.

mnarayan01 9y ago
Yes. I believe Windows requires you to specify a maximum reserved stack size in the program executable. That's...not going to happen for e.g. Linux.
- smhenderson 9y ago
  That's correct and any of the various MS runtime libraries simply set it by default if you didn't. Thus this error[1] (in C) and this[2] (in VB). I remember these from pre-dotNet days but based on the second link it looks not much has changed in VB.net. [1]https://msdn.microsoft.com/en-us/library/aa264523(v=vs.60).aspx https://msdn.microsoft.com/en-us/library/aa264523(v=vs.60).a... [2]https://docs.microsoft.com/en-us/dotnet/visual-basic/language-reference/error-messages/out-of-stack-space https://docs.microsoft.com/en-us/dotnet/visual-basic/languag...
- clarry 9y ago
  The reservation is not particularly relevant though.
- IshKebab 9y ago
  So how does it detect stack overflows past that limit? Edit: Looks like a fix for LLVM being proposed (https://reviews.llvm.org/D9653 https://reviews.llvm.org/D9653) is just to probe every page that a stack allocation covers, rather than just the final one. Doesn't sound tough at all.

daveguy 9y ago

So the title should read "is not closed"? The parenthesis are just annoying. It's one or the other, just state it! Readers shouldn't have to solve a puzzle to read a title.

sdrothrock 9y ago
First read to me as someone who hadn't read the article was "someone found an ancient kernel hole and declared it closed, but in truth it's actually not," which actually seems to be what was intended... it's a fairly common use of "(not)."
nullc 9y ago
The title is a play on a 2010 LWN headline. This is explained in the article. But reading the article has never been a barrier for HN editing a headline to make it less accurate in the past, so why start now? :)
CaliforniaKarl 9y ago
I'm sorry, I'm really confused now. Here's the title of the article: An Ancient Kernel Hole is (Not) Closed I thought that I copy-pasted the article title to be the title of this submission. Did I omit the parenthesis? If so, it was unintentional, and I apologize.
- enzanki_ars 9y ago
  HN automatically removes certain punctuation from post titles. In a lot of cases though, it creates more confusion. Definitely not your fault.
  - CaliforniaKarl 9y ago
    I did not know that! I'm tempted to experiment now 8-) Thanks for the heads-up!