From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f48.google.com (mail-ot1-f48.google.com [209.85.210.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07C7317107F for ; Fri, 12 Jul 2024 15:24:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720797862; cv=none; b=Wu4FgPBw6ossnXLYVZnefhdlsZ4/UIBLTO0C8V5UZn5O5ltHO21rnddlCaASQUV4/bDrSW0zM1Mmdgn8fTHRpIGQrZf/oQCL5Wi2Awpb9XsafbRI3vQe6aQKfZi4Re7B8QenMkWA6NwPz3xJIG2fxZZE9xtBP3HwgVRKPd8C1Ws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720797862; c=relaxed/simple; bh=JUIYKvNGMO1SkEFWn1mAumut1m0hlrfblgDfUKPWoG8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Zkm50Fm1jUO9Q/B5cT9OA26mXamB5Oku388bi1hLmFmbyw3Gq2v5afAQkwm/07pcDw5R1e5HbR4sGfCB2AgS5ADMwfXYJsCAL51WnZLDgQ/VisVHfjR/J+75R384LkqUe4R7IfAdrOuec9PWcGONb0JsSnCMouSbt4dVEDCWGnA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=y0XlprMU; arc=none smtp.client-ip=209.85.210.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="y0XlprMU" Received: by mail-ot1-f48.google.com with SMTP id 46e09a7af769-7044c085338so1168967a34.2 for ; Fri, 12 Jul 2024 08:24:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1720797859; x=1721402659; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=XOA2L08mCuyMKs7XPaxLTpydVxQBasV234XE4bUYJ3U=; b=y0XlprMUS+oy9DU4sUy/0ZudT8j65KKPEav1FaBilR+l/I044auW3Adab7UZV52jTG lvSCPETWoTYcMi/2TXwCHOMIv5cXpeICfh3DrF9jR7MBvJKkJ2a9e+O7o4qlxlkW3a6a S5unt9jLYCyjKt4eSF2QEFFnES8tUh/rLjBsFvP9mDqKrn2IGJJr0EXmN+R8w31596tm sHvZ0QnuyfSppdoTAIirMFQyrWtGsomSWxhwGextvgeOZec/afCLui3NyM1zj06oA078 DG68vJU9+iHZaSNxaEZIa9g4SDBgpGN+tb5sDwFkwstWhiE+FKLdjj3CDIYLE/nIUCjx oURQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720797859; x=1721402659; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=XOA2L08mCuyMKs7XPaxLTpydVxQBasV234XE4bUYJ3U=; b=ugwU7GG1FuVYHBAkLbRB36u7FNTzUp66ggYyDeVdejQMSKlx9YZ7mTI/vsLbASJIm0 w/ej2cqgFVwoeAeH683AQ5A2fNyOT/oXNVSkHTgTHoT5KCH63720Elb2drjyCeQfvT4V Ca8BzEumEbWKYhsBc4SalImfju6PposseSa/BWt2rsh7+/3fSI0Bru7ZuBI1K2n3/vFv sKKvRLmXEZC5xHnk4yCQxcoJAejbK2XNYCKdve3e/+Zq1IDshV6c3TnTQaFVfT9ESzhk 5cRZMan+gMQkJ+/Pfux1yQVgq/yR7cgmvy6utNVesSBcEp3SAwstcu7b72yQxWsg7dsa Lq2g== X-Forwarded-Encrypted: i=1; AJvYcCXCXnQG1FNACrE2QgyY94AoUI+nFSTVB15H9PSeIDYbm9TKq3L36sqD7YTKoEyUychYYGOIneyY6JEi+U1rr46bDx4aWNqMGOcBXeE/ X-Gm-Message-State: AOJu0YxuElzpQkKsuvznpYObTB26tPToy64gzT03+bU6GgDeR4qpwZ7j giHV3pRvLkwOwLbndqtLqp8PwzTBS5iw7ZclQk7YelezJ8JyKRFSvhe1wfU8Jac= X-Google-Smtp-Source: AGHT+IHwCLkJMA2vjY+7LA6BuyvexxnE9zT0HUloLMcdEh0siZLGbZEjCyL4Rw3Md6ahmoeYYiMy5w== X-Received: by 2002:a05:6830:3b8e:b0:703:5db8:80a with SMTP id 46e09a7af769-703759fae28mr14499427a34.8.1720797859143; Fri, 12 Jul 2024 08:24:19 -0700 (PDT) Received: from localhost ([2603:8080:b800:f700::17c0]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-70374f78d92sm1608796a34.19.2024.07.12.08.24.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 12 Jul 2024 08:24:18 -0700 (PDT) Date: Fri, 12 Jul 2024 10:24:11 -0500 From: Dan Carpenter To: Bartosz Golaszewski Cc: Krzysztof Kozlowski , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: Re: [PATCH] power: sequencing: fix NULL-pointer dereference in error path Message-ID: References: <20240712144546.222119-1-brgl@bgdev.pl> <7d7dcc46-2042-439b-a744-49ae4b507839@suswa.mountain> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Jul 12, 2024 at 05:02:25PM +0200, Bartosz Golaszewski wrote: > On Fri, Jul 12, 2024 at 4:59 PM Dan Carpenter wrote: > > > > On Fri, Jul 12, 2024 at 04:45:46PM +0200, Bartosz Golaszewski wrote: > > > From: Bartosz Golaszewski > > > > > > We may call pwrseq_target_free() on a target without the final unit > > > assigned yet. In this case pwrseq_unit_put() will dereference > > > a NULL-pointer. Add a check to the latter function. > > > > > > Fixes: 249ebf3f65f8 ("power: sequencing: implement the pwrseq core") > > > Reported-by: Dan Carpenter > > > Closes: https://lore.kernel.org/linux-pm/62a3531e-9927-40f8-b587-254a2dfa47ef@stanley.mountain/ > > > Signed-off-by: Bartosz Golaszewski > > > --- > > > drivers/power/sequencing/core.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/power/sequencing/core.c b/drivers/power/sequencing/core.c > > > index 9c32b07a55e7..fe07100e4b33 100644 > > > --- a/drivers/power/sequencing/core.c > > > +++ b/drivers/power/sequencing/core.c > > > @@ -119,7 +119,8 @@ static void pwrseq_unit_release(struct kref *ref); > > > > > > static void pwrseq_unit_put(struct pwrseq_unit *unit) > > > { > > > - kref_put(&unit->ref, pwrseq_unit_release); > > > + if (unit) > > > > I was wondering where you would put the check. But it needs to be: > > > > if (!IS_ERR_OR_NULL(unit)) > > > > regards, > > dan carpenter > > > > Am I missing something? pwrseq_unit_new() can only return NULL on error. > It's not pwrseq_unit_new() but pwrseq_unit_setup() that's the issue. The target->unit = pwrseq_unit_setup() assignment in pwrseq_do_setup_targets(). regards, dan carpenter