vhost: vringh: use krealloc_array()

Use the helper that checks for overflows internally instead of manually
calculating the size of the new array.

Link: https://lkml.kernel.org/r/20201109110654.12547-5-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: David Rientjes <rientjes@google.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/vhost/vringh.c

@@ -198,7 +198,8 @@ static int resize_iovec(struct vringh_kiov *iov, gfp_t gfp)
 
 	flag = (iov->max_num & VRINGH_IOV_ALLOCATED);
 	if (flag)
-		new = krealloc(iov->iov, new_num * sizeof(struct iovec), gfp);
+		new = krealloc_array(iov->iov, new_num,
+				     sizeof(struct iovec), gfp);
 	else {
 		new = kmalloc_array(new_num, sizeof(struct iovec), gfp);
 		if (new) {