linux-kernel - Re: [PATCH] mm: Fix wrong kunmap

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:	Sun, 5 Jun 2011 12:20:50 -0700 (PDT)
From:	Hugh Dickins <hughd@...gle.com>
To:	Steven Rostedt <rostedt@...dmis.org>
cc:	LKML <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Mel Gorman <mel@....ul.ie>
Subject: Re: [PATCH] mm: Fix wrong kunmap_atomic() pointer

On Fri, 3 Jun 2011, Steven Rostedt wrote:
> 
> Signed-off-by: Steven Rostedt <rostedt@...dmis.org>

Thanks, Steve: I'm afraid I left a number of those "pte - 1"
landmines around, and this isn't the first one to blow up.

Acked-by: Hugh Dickins <hughd@...gle.com>

> diff --git a/mm/memory.c b/mm/memory.c
> index 6953d39..922dcd6 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1112,11 +1112,13 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
>  	int force_flush = 0;
>  	int rss[NR_MM_COUNTERS];
>  	spinlock_t *ptl;
> +	pte_t *start_pte;
>  	pte_t *pte;
>  
>  again:
>  	init_rss_vec(rss);
> -	pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
> +	start_pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
> +	pte = start_pte;
>  	arch_enter_lazy_mmu_mode();
>  	do {
>  		pte_t ptent = *pte;
> @@ -1196,7 +1198,7 @@ again:
>  
>  	add_mm_rss_vec(mm, rss);
>  	arch_leave_lazy_mmu_mode();
> -	pte_unmap_unlock(pte - 1, ptl);
> +	pte_unmap_unlock(start_pte, ptl);
>  
>  	/*
>  	 * mmu_gather ran out of room to batch pages, we break out of
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/