There are some potential integer overflows here on 64 bit systems. The condition "if (nfences > SIZE_MAX / sizeof(*fences))" can only be true on 32 bit systems, it's a no-op on 64 bit, so let's ignore the check for now and look a couple lines after: if (!access_ok(VERIFY_READ, user, nfences * 2 * sizeof(u32))) ^^^^^^^^^^^ "nfences" is an unsigned int, so if we set it to UINT_MAX and multiply by two, it's going to have an integer overflow. The "args->buffer_count" is also an unsigned int so it could overflow if it's set to UINT_MAX when we do: exec2_list = kvmalloc_array(args->buffer_count + 1, sz, ^^^^^^^^^^^^^^^^^^^^^^ Fixes: 2889caa92321 ("drm/i915: Eliminate lots of iterations over the execobjects array") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 15ab3e6792f9..f569721aad1a 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -2152,7 +2152,7 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args, if (!(args->flags & I915_EXEC_FENCE_ARRAY)) return NULL; - if (nfences > SIZE_MAX / sizeof(*fences)) + if (nfences > UINT_MAX / sizeof(*fences)) return ERR_PTR(-EINVAL); user = u64_to_user_ptr(args->cliprects_ptr); @@ -2520,7 +2520,7 @@ i915_gem_execbuffer(struct drm_device *dev, void *data, unsigned int i; int err; - if (args->buffer_count < 1 || args->buffer_count > SIZE_MAX / sz - 1) { + if (args->buffer_count < 1 || args->buffer_count > UINT_MAX / sz - 1) { DRM_DEBUG("execbuf2 with %d buffers\n", args->buffer_count); return -EINVAL; } @@ -2609,7 +2609,7 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data, struct drm_syncobj **fences = NULL; int err; - if (args->buffer_count < 1 || args->buffer_count > SIZE_MAX / sz - 1) { + if (args->buffer_count < 1 || args->buffer_count > UINT_MAX / sz - 1) { DRM_DEBUG("execbuf2 with %d buffers\n", args->buffer_count); return -EINVAL; } _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx