On Tue, 10 Jan 2012 17:30:22 +0100
Michal Hocko <mhocko@xxxxxxx> wrote:
> This patch fixes the following NULL ptr dereference caused by
> cat /sys/devices/system/memory/memory0/removable:
Which is world-readable, I assume?
> ...
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5608,6 +5608,17 @@ __count_immobile_pages(struct zone *zone, struct page *page, int count)
> bool is_pageblock_removable_nolock(struct page *page)
> {
> struct zone *zone = page_zone(page);
> + unsigned long pfn = page_to_pfn(page);
> +
> + /*
> + * We have to be careful here because we are iterating over memory
> + * sections which are not zone aware so we might end up outside of
> + * the zone but still within the section.
> + */
> + if (!zone || zone->zone_start_pfn > pfn ||
> + zone->zone_start_pfn + zone->spanned_pages <= pfn)
> + return false;
> +
> return __count_immobile_pages(zone, page, 0);
> }
So I propose that we backport it into -stable?
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>