From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) (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 60BF413A409; Wed, 9 Oct 2024 08:00:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.21 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728460848; cv=none; b=oBz/HO25k07bnN1Uc0VHQ+INka4Sau/Y/2hSKUpkMkfPoXh2OGG+AHvn9MRfWg9xsKujDnZIrxI78+8pmZ63Y3WueEHsMnmkM82MzJI3y9d75P+Cl1Ohlvtf5c9mFWfnQ3I1U6LFyh0hnf7dEg9YlYYYco3p+/C+b5eaVD0sy4k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728460848; c=relaxed/simple; bh=X5Dfbqv7Nkw22/0CScbgBIGsF0hB+LEpROaW0FgeghM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=aZeTr9X1uDl68aKjPBntuhuU1M38k0wmkR7Ovf4I7fJLrEhKgKxlTIx1AFdxWdRDIbuuyaA9V6EYevyEIFV9HDJ+9F2dO1eCv2wJw++6PF4z1aYRDhlWHfW91KnqUZHDqpr+TVf7KQkSrGSg47rTltoSVQYxolO28ZyqEUZRyxs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=BPsRv5Eq; arc=none smtp.client-ip=198.175.65.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="BPsRv5Eq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1728460848; x=1759996848; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=X5Dfbqv7Nkw22/0CScbgBIGsF0hB+LEpROaW0FgeghM=; b=BPsRv5Eqf8dQGGT3gi/zHeWfwfeB6FWlOSg7KK86zoh7tkrcEY+nQMiB oL9WP7DmfiGpTy3/hvDOE1kHSAylTn/5RrlDvK92GwrXUhpnZiv8L85DI FZdTjo+rUGGn7XncYSBDM90oHXlqFIAIGei+aj2R8NYwajxJvB15aIEv/ p/q95O7bb6d1aSRfDz9hQg4uvVMg2SxIHimrCboYK/p460urMWhQ6nKq3 ygg0f8rR71PwT7z0k+aaI/5xOOB1Of/Xfpm86Q5b9GVgMzMHhAPGJru7D DQN/Bndeb4r2OgGBLanCDfRcpiCWp2gPw3vUbUsaTW4jHKxD3aZzmHmiz g==; X-CSE-ConnectionGUID: P4QTZUUGT5WkkdGFA1V/kA== X-CSE-MsgGUID: qGz7ZnZXR/eaBlMCrAJiAg== X-IronPort-AV: E=McAfee;i="6700,10204,11219"; a="27694024" X-IronPort-AV: E=Sophos;i="6.11,189,1725346800"; d="scan'208";a="27694024" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2024 01:00:47 -0700 X-CSE-ConnectionGUID: K98xMOjVSFOEkwHLmsYsCA== X-CSE-MsgGUID: OR7jKexLTJuREao8BW2T6w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,189,1725346800"; d="scan'208";a="76989952" Received: from yarbov-mobl2.ger.corp.intel.com (HELO [10.245.131.59]) ([10.245.131.59]) by orviesa008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2024 01:00:41 -0700 Message-ID: Date: Wed, 9 Oct 2024 10:00:36 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm/xe/guc: Fix deference after check To: "Everest K.C." , lucas.demarchi@intel.com, thomas.hellstrom@linux.intel.com, rodrigo.vivi@intel.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch Cc: skhan@linuxfoundation.org, intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org References: <20241008205352.4480-1-everestkc@everestkc.com.np> Content-Language: en-US From: Nirmoy Das In-Reply-To: <20241008205352.4480-1-everestkc@everestkc.com.np> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/8/2024 10:53 PM, Everest K.C. wrote: > The `if (!snapshot->copy)` evaluates to True only when `snapshot->copy` > is Null. Thus, derefrencing `snapshot->copy` inside this if block is > equivalent to Null pointer derefrencing. > The `if` condition is now changed to evaluate to true only when > `snapshot->copy` is not Null. > This issue was reported by Coverity Scan. > > Signed-off-by: Everest K.C. Fixes: d8ce1a977226 ("drm/xe/guc: Use a two stage dump for GuC logs and add more info") Reviewed-by: Nirmoy Das > --- > drivers/gpu/drm/xe/xe_guc_log.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/xe/xe_guc_log.c b/drivers/gpu/drm/xe/xe_guc_log.c > index 7fbc56cceaba..4e1a5e8ba1e3 100644 > --- a/drivers/gpu/drm/xe/xe_guc_log.c > +++ b/drivers/gpu/drm/xe/xe_guc_log.c > @@ -122,7 +122,7 @@ void xe_guc_log_snapshot_free(struct xe_guc_log_snapshot *snapshot) > if (!snapshot) > return; > > - if (!snapshot->copy) { > + if (snapshot->copy) { > for (i = 0; i < snapshot->num_chunks; i++) > kfree(snapshot->copy[i]); > kfree(snapshot->copy);