Messages in this thread | | | From | Naoya Horiguchi <> | Subject | Re: [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 | Thu, 5 Mar 2015 08:27:29 +0000 |
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> > 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) ?
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