[PATCH 1/2] drm/i915: fix integer overflow in i915_gem_execbuffer2()

From: Xi Wang
Date: Fri Apr 06 2012 - 08:59:33 EST


A large args->buffer_count from userspace may overflow the allocation
size, leading to out-of-bounds access.

Use kmalloc_array() to avoid that.

Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index f51a696..19962bd 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1409,8 +1409,8 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data,
return -EINVAL;
}

- exec2_list = kmalloc(sizeof(*exec2_list)*args->buffer_count,
- GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
+ exec2_list = kmalloc_array(args->buffer_count, sizeof(*exec2_list),
+ GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
if (exec2_list == NULL)
exec2_list = drm_malloc_ab(sizeof(*exec2_list),
args->buffer_count);
--
1.7.5.4

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