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From: Kees Cook <keescook@chromium.org>
To: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Kees Cook <keescook@chromium.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Matthew Wilcox <willy@infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>,
	Kernel Hardening <kernel-hardening@lists.openwall.com>
Subject: [PATCH v3 08/16] device: Use overflow helpers for devm_kmalloc()
Date: Thu, 31 May 2018 17:42:25 -0700	[thread overview]
Message-ID: <20180601004233.37822-9-keescook@chromium.org> (raw)
In-Reply-To: <20180601004233.37822-1-keescook@chromium.org>

Use the overflow helpers both in existing multiplication-using inlines as
well as the addition-overflow case in the core allocation routine.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/base/devres.c  | 7 ++++++-
 include/linux/device.h | 8 ++++++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 95b67281cd2a..f98a097e73f2 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -84,9 +84,14 @@ static struct devres_group * node_to_group(struct devres_node *node)
 static __always_inline struct devres * alloc_dr(dr_release_t release,
 						size_t size, gfp_t gfp, int nid)
 {
-	size_t tot_size = sizeof(struct devres) + size;
+	size_t tot_size;
 	struct devres *dr;
 
+	/* We must catch any near-SIZE_MAX cases that could overflow. */
+	if (unlikely(check_add_overflow(sizeof(struct devres), size,
+					&tot_size)))
+		return NULL;
+
 	dr = kmalloc_node_track_caller(tot_size, gfp, nid);
 	if (unlikely(!dr))
 		return NULL;
diff --git a/include/linux/device.h b/include/linux/device.h
index 477956990f5e..897efa647203 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -25,6 +25,7 @@
 #include <linux/ratelimit.h>
 #include <linux/uidgid.h>
 #include <linux/gfp.h>
+#include <linux/overflow.h>
 #include <asm/device.h>
 
 struct device;
@@ -668,9 +669,12 @@ static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
 static inline void *devm_kmalloc_array(struct device *dev,
 				       size_t n, size_t size, gfp_t flags)
 {
-	if (size != 0 && n > SIZE_MAX / size)
+	size_t bytes;
+
+	if (unlikely(check_mul_overflow(n, size, &bytes)))
 		return NULL;
-	return devm_kmalloc(dev, n * size, flags);
+
+	return devm_kmalloc(dev, bytes, flags);
 }
 static inline void *devm_kcalloc(struct device *dev,
 				 size_t n, size_t size, gfp_t flags)
-- 
2.17.0

  parent reply	other threads:[~2018-06-01  0:46 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-01  0:42 [PATCH v3 00/16] Provide saturating helpers for allocation Kees Cook
2018-06-01  0:42 ` [PATCH v3 01/16] compiler.h: enable builtin overflow checkers and add fallback code Kees Cook
2018-06-01  0:42 ` [PATCH v3 02/16] lib: add runtime test of check_*_overflow functions Kees Cook
2018-06-01  0:42 ` [PATCH v3 03/16] lib: overflow: Report test failures Kees Cook
2018-06-01  0:42 ` [PATCH v3 04/16] overflow.h: Add allocation size calculation helpers Kees Cook
2018-06-01  0:42 ` [PATCH v3 05/16] lib: overflow: Add memory allocation overflow tests Kees Cook
2018-06-01 10:18   ` Andy Shevchenko
2018-06-01  0:42 ` [PATCH v3 06/16] mm: Use overflow helpers in kmalloc_array*() Kees Cook
2018-06-01  0:42 ` [PATCH v3 07/16] mm: Use overflow helpers in kvmalloc() Kees Cook
2018-06-01  0:42 ` Kees Cook [this message]
2018-06-01  0:42 ` [PATCH v3 09/16] treewide: Use struct_size() for kmalloc()-family Kees Cook
2018-06-01  0:42 ` [PATCH v3 10/16] treewide: Use struct_size() for vmalloc()-family Kees Cook
2018-06-01  0:42 ` [PATCH v3 11/16] treewide: Use struct_size() for devm_kmalloc() and friends Kees Cook
2018-06-01  0:42 ` [PATCH v3 12/16] treewide: Use array_size() for kmalloc()-family Kees Cook
2018-07-01  8:46   ` SF Markus Elfring
2018-07-01  8:46     ` SF Markus Elfring
2018-07-01  8:46     ` SF Markus Elfring
2018-07-01  9:03     ` Julia Lawall
2018-07-01  9:03       ` Julia Lawall
2018-07-01  9:03       ` Julia Lawall
2018-07-01  9:22       ` SF Markus Elfring
2018-07-01  9:22         ` SF Markus Elfring
2018-06-01  0:42 ` [PATCH v3 13/16] treewide: Use array_size() for kmalloc()-family, leftovers Kees Cook
2018-06-01  0:42 ` [PATCH v3 14/16] treewide: Use array_size() for vmalloc() Kees Cook
2018-06-01  0:42 ` [PATCH v3 15/16] treewide: Use array_size() for devm_*alloc()-like Kees Cook
2018-06-01  0:42 ` [PATCH v3 16/16] treewide: Use array_size() for devm_*alloc()-like, leftovers Kees Cook
2018-06-01  0:54 ` [PATCH v3 00/16] Provide saturating helpers for allocation Linus Torvalds
2018-06-01  4:18   ` Kees Cook

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