Merge tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull overflow updates from Kees Cook:
 "This adds the new overflow checking helpers and adds them to the
  2-factor argument allocators. And this adds the saturating size
  helpers and does a treewide replacement for the struct_size() usage.
  Additionally this adds the overflow testing modules to make sure
  everything works.

  I'm still working on the treewide replacements for allocators with
  "simple" multiplied arguments:

     *alloc(a * b, ...) -> *alloc_array(a, b, ...)

  and

     *zalloc(a * b, ...) -> *calloc(a, b, ...)

  as well as the more complex cases, but that's separable from this
  portion of the series. I expect to have the rest sent before -rc1
  closes; there are a lot of messy cases to clean up.

  Summary:

   - Introduce arithmetic overflow test helper functions (Rasmus)

   - Use overflow helpers in 2-factor allocators (Kees, Rasmus)

   - Introduce overflow test module (Rasmus, Kees)

   - Introduce saturating size helper functions (Matthew, Kees)

   - Treewide use of struct_size() for allocators (Kees)"

* tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  treewide: Use struct_size() for devm_kmalloc() and friends
  treewide: Use struct_size() for vmalloc()-family
  treewide: Use struct_size() for kmalloc()-family
  device: Use overflow helpers for devm_kmalloc()
  mm: Use overflow helpers in kvmalloc()
  mm: Use overflow helpers in kmalloc_array*()
  test_overflow: Add memory allocation overflow tests
  overflow.h: Add allocation size calculation helpers
  test_overflow: Report test failures
  test_overflow: macrofy some more, do more tests for free
  lib: add runtime test of check_*_overflow functions
  compiler.h: enable builtin overflow checkers and add fallback code

drivers/misc/cb710/core.c

@@ -232,8 +232,8 @@ static int cb710_probe(struct pci_dev *pdev,
 	if (val & CB710_SLOT_SM)
 		++n;
 
-	chip = devm_kzalloc(&pdev->dev,
-		sizeof(*chip) + n * sizeof(*chip->slot), GFP_KERNEL);
+	chip = devm_kzalloc(&pdev->dev, struct_size(chip, slot, n),
+			    GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;
 

drivers/misc/vexpress-syscfg.c

@@ -182,8 +182,7 @@ static struct regmap *vexpress_syscfg_regmap_init(struct device *dev,
 		val = energy_quirk;
 	}
 
-	func = kzalloc(sizeof(*func) + sizeof(*func->template) * num,
-			GFP_KERNEL);
+	func = kzalloc(struct_size(func, template, num), GFP_KERNEL);
 	if (!func)
 		return ERR_PTR(-ENOMEM);