[Tarantool-patches] [PATCH luajit] Fix limit check in narrow_conv_backprop().

[Sergey Kaplun]

Hi, Maxim!
Thanks for the review!
Fixed your comments and force-pushed the branch.

On 23.09.24, Maxim Kokryashkin wrote:
> Hi, Sergey!
> Thanks for the patch!
> LGTM, except for a few nits below.
> 
> On Mon, Aug 26, 2024 at 03:37:40PM GMT, Sergey Kaplun wrote:
> > From: Mike Pall <mike>
> >
> > Thanks to Sergey Kaplun.
> >
> > (cherry picked from commit e45fd4cb713b610506213692f3b55a1869febb03)
> >
> > `narrow_conv_backprop()` misses the stack pointer (`nc->sp`) limit check
> > after a bunch of recursive calls that may change its value. As a result,
> It took me a minute to understand that sentence. Let's paraphrase it the
> following way:
> 
> | The function narrow_conv_backprop() does not include a limit
> | check for the stack pointer (nc->sp), even though its value may
> | change after several recursive calls.

Rephrased as you suggested. The new commit message is the following:

| Fix limit check in narrow_conv_backprop().
|
| Thanks to Sergey Kaplun.
|
| (cherry picked from commit e45fd4cb713b610506213692f3b55a1869febb03)
|
| The function `narrow_conv_backprop()` does not include a limit check for
| the stack pointer (`nc->sp`), even though its value may change after
| several recursive calls. As a result, it leads to stack-buffer-overflow
| during the instruction narrowing. This patch adds the missing check.
|
| Sergey Kaplun:
| * added the description and the test for the problem
|
| Part of tarantool/tarantool#10199

> 
> > it leads to stack-buffer-overflow during the instruction narrowing. This
> > patch adds a missing check.
> Typo: s/a missing/the missing

Fixed, thanks!

> 
> >
> > Sergey Kaplun:
> > * added the description and the test for the problem
> >
> > Part of tarantool/tarantool#10199
> > ---
> >
> > Branch: https://github.com/tarantool/luajit/tree/skaplun/lj-1262-fix-limit-narrow-conv-backprop
> > Related issues:
> > * https://github.com/tarantool/tarantool/issues/10199
> > * https://github.com/LuaJIT/LuaJIT/issues/1262
> 
> <snipped>

-- 
Best regards,
Sergey Kaplun