From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752417Ab2DQTan (ORCPT ); Tue, 17 Apr 2012 15:30:43 -0400 Received: from smtp5-g21.free.fr ([212.27.42.5]:50765 "EHLO smtp5-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751178Ab2DQTaR (ORCPT ); Tue, 17 Apr 2012 15:30:17 -0400 From: Jim Meyering To: Ben Skeggs Cc: Linux Kernel Mailing List Subject: [PATCH] drm/nouveau/pm: don't read/write beyond end of stack buffer Date: Tue, 17 Apr 2012 21:27:54 +0200 Message-ID: <87d37640qt.fsf@rho.meyering.net> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org NUL-terminate after strncpy. If the parameter "profile" has length 16 or more, then strncpy leaves "string" with no NUL terminator, so the following search for '\n' may read beyond the end of that 16-byte buffer. If it finds a newline there, then it will also write beyond the end of that stack buffer. Signed-off-by: Jim Meyering --- drivers/gpu/drm/nouveau/nouveau_pm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/nouveau/nouveau_pm.c b/drivers/gpu/drm/nouveau/nouveau_pm.c index 34d591b..da3e7c3 100644 --- a/drivers/gpu/drm/nouveau/nouveau_pm.c +++ b/drivers/gpu/drm/nouveau/nouveau_pm.c @@ -225,26 +225,27 @@ profile_find(struct drm_device *dev, const char *string) static int nouveau_pm_profile_set(struct drm_device *dev, const char *profile) { struct drm_nouveau_private *dev_priv = dev->dev_private; struct nouveau_pm_engine *pm = &dev_priv->engine.pm; struct nouveau_pm_profile *ac = NULL, *dc = NULL; char string[16], *cur = string, *ptr; /* safety precaution, for now */ if (nouveau_perflvl_wr != 7777) return -EPERM; strncpy(string, profile, sizeof(string)); + string[sizeof(string) - 1] = 0; if ((ptr = strchr(string, '\n'))) *ptr = '\0'; ptr = strsep(&cur, ","); if (ptr) ac = profile_find(dev, ptr); ptr = strsep(&cur, ","); if (ptr) dc = profile_find(dev, ptr); else dc = ac; -- 1.7.10.208.gb4267