From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Gardner Subject: [PATCH v2 3.7-rc8] ttm: Fix possible _manager memory allocation oops Date: Fri, 7 Dec 2012 07:16:22 -0700 Message-ID: <1354889782-16830-1-git-send-email-tim.gardner@canonical.com> References: Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Tim Gardner , David Airlie , Dave Airlie , "Paul E. McKenney" , Zhao Yakui , David Howells , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org Memory for _manager is allocated using kzalloc() but the result is not checked. I was led to scrutinize ttm_page_alloc_init() from a smatch warning: drivers/gpu/drm/ttm/ttm_page_alloc.c:799 ttm_page_alloc_init() error: potential null dereference '_manager'. (kzalloc returns null) Cc: David Airlie Cc: Dave Airlie Cc: "Paul E. McKenney" Cc: Zhao Yakui Cc: David Howells Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # 3.5+ Signed-off-by: Tim Gardner --- This patch applies to stable 3.5 and newer. V2 - kobject_put(&_manager->kobj) uses a destructor and container_of() to free _mamanger. drivers/gpu/drm/ttm/ttm_page_alloc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c index bd2a3b4..c64e96c 100644 --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c @@ -798,6 +798,10 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages) pr_info("Initializing pool allocator\n"); _manager = kzalloc(sizeof(*_manager), GFP_KERNEL); + if (!_manager) { + pr_err("ttm: Could not allocate _manager.\n"); + return -ENOMEM; + } ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc"); -- 1.7.9.5