From: Dan Carpenter <[email protected]> [ Upstream commit 4b408c74ee5a0b74fc9265c2fe39b0e7dec7c056 ]
The concern here is that "gup->size" is a u64 and "nr_pages" is unsigned long. On 32 bit systems we could trick the kernel into allocating fewer pages than expected. Link: http://lkml.kernel.org/r/[email protected] Fixes: 64c349f4ae78 ("mm: add infrastructure for get_user_pages_fast() benchmarking") Signed-off-by: Dan Carpenter <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Stephen Rothwell <[email protected]> Cc: Keith Busch <[email protected]> Cc: "Michael S. Tsirkin" <[email protected]> Cc: Kees Cook <[email protected]> Cc: YueHaibing <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- mm/gup_benchmark.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c index 7405c9d89d65..7e6f2d2dafb5 100644 --- a/mm/gup_benchmark.c +++ b/mm/gup_benchmark.c @@ -23,6 +23,9 @@ static int __gup_benchmark_ioctl(unsigned int cmd, int nr; struct page **pages; + if (gup->size > ULONG_MAX) + return -EINVAL; + nr_pages = gup->size / PAGE_SIZE; pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL); if (!pages) -- 2.17.1
