[PATCH 2/2] drm/i915: fix integer overflow in i915_gem_do_execbuffer()

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


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

| i915_gem_do_execbuffer()
| i915_gem_execbuffer()

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 19962bd..607be3d 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1133,8 +1133,8 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
return -EINVAL;
}

- cliprects = kmalloc(args->num_cliprects * sizeof(*cliprects),
- GFP_KERNEL);
+ cliprects = kmalloc_array(args->num_cliprects, sizeof(*cliprects),
+ GFP_KERNEL);
if (cliprects == NULL) {
ret = -ENOMEM;
goto pre_mutex_err;
--
1.7.5.4

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