From: Miles Chen <miles.c...@mediatek.com> [ Upstream commit c8f61cfc871fadfb73ad3eacd64fda457279e911 ]
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. [a...@linux-foundation.org: use min_t()] Link: http://lkml.kernel.org/r/1541091607-27402-1-git-send-email-miles.c...@mediatek.com Signed-off-by: Miles Chen <miles.c...@mediatek.com> Acked-by: Michal Hocko <mho...@suse.com> Cc: Joe Perches <j...@perches.com> Cc: Matthew Wilcox <wi...@infradead.org> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Sasha Levin <sas...@kernel.org> --- mm/page_owner.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/page_owner.c b/mm/page_owner.c index d80adfe702d3..9ad588444671 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; -- 2.19.1
