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authorDan Carpenter <dan.carpenter@oracle.com>2018-10-30 15:04:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-31 08:54:12 -0700
commit4b408c74ee5a0b74fc9265c2fe39b0e7dec7c056 (patch)
tree246fef299b54169bc2e6c9c298df9da367021069 /mm
parentec131b2d7fa629edf88a1f51669d1b4a189cba44 (diff)
downloadlinux-4b408c74ee5a0b74fc9265c2fe39b0e7dec7c056.tar.gz
mm/gup_benchmark.c: prevent integer overflow in ioctl
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/20181025061546.hnhkv33diogf2uis@kili.mountain Fixes: 64c349f4ae78 ("mm: add infrastructure for get_user_pages_fast() benchmarking") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Keith Busch <keith.busch@intel.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/gup_benchmark.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c
index debf11388a60..5b42d3d4b60a 100644
--- a/mm/gup_benchmark.c
+++ b/mm/gup_benchmark.c
@@ -27,6 +27,9 @@ 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)