From c8f61cfc871fadfb73ad3eacd64fda457279e911 Mon Sep 17 00:00:00 2001 From: Miles Chen Date: Fri, 28 Dec 2018 00:33:21 -0800 Subject: mm/page_owner: clamp read count to PAGE_SIZE The (root-only) page owner read might allocate a large size of memory with a large read count. Allocation fails can easily occur when doing high order allocations. Clamp buffer size to PAGE_SIZE to avoid arbitrary size allocation and avoid allocation fails due to high order allocation. [akpm@linux-foundation.org: use min_t()] Link: http://lkml.kernel.org/r/1541091607-27402-1-git-send-email-miles.chen@mediatek.com Signed-off-by: Miles Chen Acked-by: Michal Hocko Cc: Joe Perches Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_owner.c | 1 + 1 file changed, 1 insertion(+) (limited to 'mm/page_owner.c') diff --git a/mm/page_owner.c b/mm/page_owner.c index 87bc0dfdb52b..28b06524939f 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -351,6 +351,7 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, .skip = 0 }; + count = min_t(size_t, count, PAGE_SIZE); kbuf = kmalloc(count, GFP_KERNEL); if (!kbuf) return -ENOMEM; -- cgit v1.2.3-55-g7522