From 56ee9577915dc06f55309901012a9ef68dbdb5a8 Mon Sep 17 00:00:00 2001 From: Jianglei Nie Date: Tue, 5 Jul 2022 21:25:46 +0800 Subject: [PATCH] drm/nouveau: fix a use-after-free in nouveau_gem_prime_import_sg_table() commit 540dfd188ea2940582841c1c220bd035a7db0e51 upstream. nouveau_bo_init() is backed by ttm_bo_init() and ferries its return code back to the caller. On failures, ttm will call nouveau_bo_del_ttm() and free the memory.Thus, when nouveau_bo_init() returns an error, the gem object has already been released. Then the call to nouveau_bo_ref() will use the freed "nvbo->bo" and lead to a use-after-free bug. We should delete the call to nouveau_bo_ref() to avoid the use-after-free. Signed-off-by: Jianglei Nie Reviewed-by: Lyude Paul Signed-off-by: Lyude Paul Fixes: 019cbd4a4feb ("drm/nouveau: Initialize GEM object before TTM object") Cc: Thierry Reding Cc: # v5.4+ Link: https://patchwork.freedesktop.org/patch/msgid/20220705132546.2247677-1-niejianglei2021@163.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/nouveau/nouveau_prime.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c b/drivers/gpu/drm/nouveau/nouveau_prime.c index f9ee562f72d3..25cbe4ef383b 100644 --- a/drivers/gpu/drm/nouveau/nouveau_prime.c +++ b/drivers/gpu/drm/nouveau/nouveau_prime.c @@ -90,7 +90,6 @@ struct drm_gem_object *nouveau_gem_prime_import_sg_table(struct drm_device *dev, ret = nouveau_bo_init(nvbo, size, align, flags, sg, robj); if (ret) { - nouveau_bo_ref(NULL, &nvbo); obj = ERR_PTR(ret); goto unlock; }