diff options
| author | Kees Cook <keescook@chromium.org> | 2013-03-11 17:31:45 -0700 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2013-03-13 21:31:03 +0100 |
| commit | 3118a4f652c7b12c752f3222af0447008f9b2368 (patch) | |
| tree | 22bc815888c57441e75528c14bd1d57aa4abdc37 | |
| parent | 2563a4524febe8f4a98e717e02436d1aaf672aa2 (diff) | |
drm/i915: bounds check execbuffer relocation count
It is possible to wrap the counter used to allocate the buffer for
relocation copies. This could lead to heap writing overflows.
CVE-2013-0913
v3: collapse test, improve comment
v2: move check into validate_exec_list
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Pinkie Pie
Cc: stable@vger.kernel.org
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_execbuffer.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 2f2daebd0eef..3b11ab0fbc96 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -732,6 +732,8 @@ validate_exec_list(struct drm_i915_gem_exec_object2 *exec, int count) { int i; + int relocs_total = 0; + int relocs_max = INT_MAX / sizeof(struct drm_i915_gem_relocation_entry); for (i = 0; i < count; i++) { char __user *ptr = (char __user *)(uintptr_t)exec[i].relocs_ptr; @@ -740,10 +742,13 @@ validate_exec_list(struct drm_i915_gem_exec_object2 *exec, if (exec[i].flags & __EXEC_OBJECT_UNKNOWN_FLAGS) return -EINVAL; - /* First check for malicious input causing overflow */ - if (exec[i].relocation_count > - INT_MAX / sizeof(struct drm_i915_gem_relocation_entry)) + /* First check for malicious input causing overflow in + * the worst case where we need to allocate the entire + * relocation tree as a single array. + */ + if (exec[i].relocation_count > relocs_max - relocs_total) return -EINVAL; + relocs_total += exec[i].relocation_count; length = exec[i].relocation_count * sizeof(struct drm_i915_gem_relocation_entry); |