From 35588314e963938dfdcdb792c9170108399377d6 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Christian=20K=C3=B6nig?= Date: Fri, 25 Aug 2023 15:28:00 +0200 Subject: [PATCH] drm/amdgpu: fix amdgpu_cs_p1_user_fence MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The offset is just 32bits here so this can potentially overflow if somebody specifies a large value. Instead reduce the size to calculate the last possible offset. The error handling path incorrectly drops the reference to the user fence BO resulting in potential reference count underflow. Signed-off-by: Christian König Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index 49dd9aa8da70..efdb1c48f431 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -127,7 +127,6 @@ static int amdgpu_cs_p1_user_fence(struct amdgpu_cs_parser *p, { struct drm_gem_object *gobj; unsigned long size; - int r; gobj = drm_gem_object_lookup(p->filp, data->handle); if (gobj == NULL) @@ -137,23 +136,14 @@ static int amdgpu_cs_p1_user_fence(struct amdgpu_cs_parser *p, drm_gem_object_put(gobj); size = amdgpu_bo_size(p->uf_bo); - if (size != PAGE_SIZE || (data->offset + 8) > size) { - r = -EINVAL; - goto error_unref; - } + if (size != PAGE_SIZE || data->offset > (size - 8)) + return -EINVAL; - if (amdgpu_ttm_tt_get_usermm(p->uf_bo->tbo.ttm)) { - r = -EINVAL; - goto error_unref; - } + if (amdgpu_ttm_tt_get_usermm(p->uf_bo->tbo.ttm)) + return -EINVAL; *offset = data->offset; - return 0; - -error_unref: - amdgpu_bo_unref(&p->uf_bo); - return r; } static int amdgpu_cs_p1_bo_handles(struct amdgpu_cs_parser *p, -- 2.39.5