From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 173703A16A7 for ; Tue, 14 Apr 2026 08:20:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776154819; cv=none; b=bpd2YX/ZoSYht1F7anxwk64yO+MfrdB4DzSFuztfHlcOpfsfexdARnugpSVohEBCPYnVRBy8TAQtlS43y7BRJ93e/eH8z60wfM87zvNU3Li8PMyyE4OtmTYNo27eMyYEHX26xexw65G49wQnnDLOODUjKnqYtQUIMhDRFFHIy1U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776154819; c=relaxed/simple; bh=2cAwolY5z2GXVz3PlWBCXl25KcupGpdiCLYh6FZ6Y58=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NgIlUbZ/RxYPOeX0BRewdWVjFMVBCfRcJ1YOTbmVW4N7jiBapz0Chr0oanTo4IRc4JeXmkIHq4oAIkUJg8yM4T3l1fS/SApngPNdxnF5BTxxMkaootToBWtX7lq8myvNGI39qFROuib9X5trX+R63ydLAz8H5uBU4MeRrq2gaS4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=hv/msIbf; arc=none smtp.client-ip=192.198.163.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="hv/msIbf" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1776154818; x=1807690818; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=2cAwolY5z2GXVz3PlWBCXl25KcupGpdiCLYh6FZ6Y58=; b=hv/msIbfZLsPJGoBTtu7rHLEHCNM6cclCxGWj5mFTErrjd3o+lF5Nxz4 hlcZIrrx6xPwOwcrDbfGgPnXdzjPdADTWA01ftnk7HOVcbhw2yZ9Aks20 f8g9FpWUfNVkpZ1p/ftYtxUguMKmk7Taz6Rpa1mmRWW9tYJ2hnzNBU3io X1V2yAVCUHIG4ix4mKFawdtiw4Ct5IkVJdrGCJKn+yGc23rj36ePHemeA fpZk0WFh1jZaaHi0KHXQVtUkuLKON22NVcZDrEyGZIC9fQt+OYXSjQJIF YeuhmB6x5YVTxMptfpefmrAkeor6PxX8tFOr0XfeQrQCQEvWuiLOeuN1Q A==; X-CSE-ConnectionGUID: mI3JqqGmQcSw+ZWtYjURSA== X-CSE-MsgGUID: Gt/LqWIiSv27egkRMjYOrg== X-IronPort-AV: E=McAfee;i="6800,10657,11758"; a="77215906" X-IronPort-AV: E=Sophos;i="6.23,179,1770624000"; d="scan'208";a="77215906" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2026 01:20:17 -0700 X-CSE-ConnectionGUID: htPIXgnDQ2qwboE1oGN/aw== X-CSE-MsgGUID: uHDivzrvSKWPZNTEKiQSVA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,179,1770624000"; d="scan'208";a="228990646" Received: from pgcooper-mobl3.ger.corp.intel.com (HELO localhost) ([10.245.245.106]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2026 01:20:15 -0700 Date: Tue, 14 Apr 2026 11:20:12 +0300 From: Andy Shevchenko To: Dan Carpenter Cc: Shyam Sunder Reddy Padira , gregkh@linuxfoundation.org, ethantidmore06@gmail.com, nayana.mariyappa@gmail.com, s9430939@naver.com, kees@kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] staging: rtl8723bs: os_dep: avoid NULL pointer dereference in rtw_cbuf_alloc Message-ID: References: <20260413224417.5674-2-shyamsunderreddypadira@gmail.com> <20260414071308.4781-2-shyamsunderreddypadira@gmail.com> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Tue, Apr 14, 2026 at 11:00:02AM +0300, Dan Carpenter wrote: > On Tue, Apr 14, 2026 at 10:55:56AM +0300, Dan Carpenter wrote: > > On Tue, Apr 14, 2026 at 10:46:13AM +0300, Andy Shevchenko wrote: > > > On Tue, Apr 14, 2026 at 12:43:06PM +0530, Shyam Sunder Reddy Padira wrote: ... > > > > --- a/drivers/staging/rtl8723bs/os_dep/osdep_service.c > > > > +++ b/drivers/staging/rtl8723bs/os_dep/osdep_service.c > > > > @@ -194,7 +194,8 @@ struct rtw_cbuf *rtw_cbuf_alloc(u32 size) > > > > struct rtw_cbuf *cbuf; > > > > > > > > cbuf = kzalloc_flex(*cbuf, bufs, size); > > > > - cbuf->size = size; > > > > + if (cbuf) > > > > + cbuf->size = size; > > > > > > > > return cbuf; > > > > > > Now to the code. This is still buggy. The problem is that the size is not > > > validated and when it's 0, the same issue (dereference of invalid pointer) > > > will happen. > > > > > > Dan, JFYI k*alloc*(0) returns not NULL and not valid pointer. > > > > kzalloc_flex() basically can't return the ZERO_SIZE pointer. > > I meant ZERO_SIZE_PTR. Ah, true, I missed the _flex vs. _objs part. Then the patch is fine as is. -- With Best Regards, Andy Shevchenko