linux-kernel - Re: [PATCH] mm/migrate: Fix early increment of migrate->npages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20171002214823.GB5184@redhat.com>
Date:   Mon, 2 Oct 2017 17:48:23 -0400
From:   Jerome Glisse <jglisse@...hat.com>
To:     Reza Arbab <arbab@...ux.vnet.ibm.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Balbir Singh <bsingharora@...il.com>,
        Naoya Horiguchi <n-horiguchi@...jp.nec.com>,
        Minchan Kim <minchan@...nel.org>,
        Johannes Weiner <hannes@...xchg.org>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mm/migrate: Fix early increment of migrate->npages

On Mon, Oct 02, 2017 at 04:44:02PM -0500, Reza Arbab wrote:
> The intention here is to set the same array element in src and dst.
> Switch the order of these lines so that migrate->npages is only
> incremented after we've used it.

I already posted a fix for this today from Mark. Either version is
fine i think Andrew already pulled version i posted earlier.

> 
> Fixes: 8315ada7f095 ("mm/migrate: allow migrate_vma() to alloc new page on empty entry")
> Cc: Jérôme Glisse <jglisse@...hat.com>
> Signed-off-by: Reza Arbab <arbab@...ux.vnet.ibm.com>
> ---
>  mm/migrate.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/migrate.c b/mm/migrate.c
> index dea0ceb..c4546cc 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -2146,8 +2146,8 @@ static int migrate_vma_collect_hole(unsigned long start,
>  	unsigned long addr;
>  
>  	for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) {
> -		migrate->src[migrate->npages++] = MIGRATE_PFN_MIGRATE;
>  		migrate->dst[migrate->npages] = 0;
> +		migrate->src[migrate->npages++] = MIGRATE_PFN_MIGRATE;
>  		migrate->cpages++;
>  	}
>  
> -- 
> 1.8.3.1
>