lkml.org 
[lkml]   [2015]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH] mm: pagewalk: prevent positive return value of walk_page_test() from being passed to callers (Re: [PATCH] mm: fix do_mbind return value)
Date
> > From 107fa3fb256bddff40a882c90af717af9863aed7 Mon Sep 17 00:00:00 2001
> > From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> > Date: Thu, 5 Mar 2015 16:37:37 +0900
> > Subject: [PATCH] mm: pagewalk: prevent positive return value of
> > walk_page_test() from being passed to callers
> >
> > walk_page_test() is purely pagewalk's internal stuff, and its positive return
> > values are not intended to be passed to the callers of pagewalk. However, in
> > the current code if the last vma in the do-while loop in walk_page_range()
> > happens to return a positive value, it leaks outside walk_page_range().
> > So the user visible effect is invalid/unexpected return value (according to
> > the reporter, mbind() causes it.)
> >
> > This patch fixes it simply by reinitializing the return value after checked.
> >
> > Another exposed interface, walk_page_vma(), already returns 0 for such cases
> > so no problem.
> >
> > Fixes: 6f4576e3687b ("mempolicy: apply page table walker on queue_pages_range()")
>
> This is not a right tag. To be precise, the bug was introduced by commit
> fafaa4264eba ("pagewalk: improve vma handling"), so
>
> Fixes fafaa4264eba ("pagewalk: improve vma handling")
>
> is right.
>
> Thanks,
> Naoya Horiguchi
>
> > Reported-by: Kazutomo Yoshii <kazutomo.yoshii@gmail.com>

Ah, I might be a kind of rude, the original idea was posted by Yoshii-san,
and I changed it, so I may as well add his Signed-off-by (additional to
Reported-by) ?

\
 
 \ /
  Last update: 2015-03-05 09:41    [W:0.065 / U:0.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site