Re: [PATCH net] tls: don't use stack memory in a scatterlist

From: David Miller
Date: Thu May 17 2018 - 15:46:18 EST


From: Matt Mullins <mmullins@xxxxxx>
Date: Thu, 17 May 2018 20:28:46 +0000

> On Thu, 2018-05-17 at 14:50 -0400, David Miller wrote:
>> I'm surprised this problem wasn't discovered sooner. How exactly did you
>> discover it? Did you actually see it trigger or is this purely from code
>> inspection?
>
> Honestly, I'm not sure how it got uncovered, but it was observed at
> runtime. Doron Roberts-Kedes hit a null pointer dereference so we
> turned on CONFIG_DEBUG_SG -- then it became a proper
> BUG_ON(!virt_addr_valid(buf)); in sg_set_buf.

Fair enough, thanks for the info.