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Commit d1d78830 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Prevent integer overflow when validating the execbuffer 



Commit 2549d6c2 removed the vmalloc used for temporary storage of the
relocation lists used during execbuffer. However, our use of vmalloc was
being protected by an integer overflow check which we do want to
preserve!

Reported-by: default avatarDan Carpenter <error27@gmail.com>
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
parent 16c59ef3

drivers/gpu/drm/i915/i915_gem.c

+8 −1
Original line number Diff line number Diff line
@@ -3630,8 +3630,15 @@ validate_exec_list(struct drm_i915_gem_exec_object2 *exec, 


	for (i = 0; i < count; i++) {

		char __user *ptr = (char __user *)(uintptr_t)exec[i].relocs_ptr;

		size_t length = exec[i].relocation_count * sizeof(struct drm_i915_gem_relocation_entry);

		int length; /* limited by fault_in_pages_readable() */



		/* First check for malicious input causing overflow */

		if (exec[i].relocation_count >

		    INT_MAX / sizeof(struct drm_i915_gem_relocation_entry))

			return -EINVAL;



		length = exec[i].relocation_count *

			sizeof(struct drm_i915_gem_relocation_entry);

		if (!access_ok(VERIFY_READ, ptr, length))

			return -EFAULT;