From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 50DD933B979; Mon, 26 Jan 2026 15:24:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769441062; cv=none; b=jrISUblbVSDQBRcvwdiQ00GHzs4/pEuk4RRHiZZPzg44i15ASz97nEbgQ7uIRhtKcCpAroyvBBERtQ9wEXzQLNNBPT35ESfk4DA8ebctjY2a6DCbQuOln6mAdHie/TimUz4fKu+shDRLG/T7Qzn2BO5qVdY+biHbN74vJYnk07g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769441062; c=relaxed/simple; bh=si1LFN6ROqn1g02PVvuwyz0atQYO6Ys4XxkHlnrqqPw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=t81N9Pt8Owm97ZaX3e6vSr5aIYUe6tQIi6Re7OBjT/z8Wb9KU5xJS4w1nD2fQcl/sau60h8j+3ew0gLAd/exAy9jLj3xqpZL+LM9Bq94d9WoLg8ZHlz35nBPyD6tukc18U+O2Z4S4I/0n3v04S/uCm9fyUY/GoKOPM5IW4P47UI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FIxvYjEC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FIxvYjEC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EF6DC116C6; Mon, 26 Jan 2026 15:24:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1769441061; bh=si1LFN6ROqn1g02PVvuwyz0atQYO6Ys4XxkHlnrqqPw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FIxvYjECDa2TDFkLGxmDy8w+xKoxWqx9f/rmgKo2ogvWI1uEl6uZUeuKrQE1m42hd 07RbG3nFmTN+0jCPM9pjQE1CzOUziCJz6PW6FDuNv60jqtRmFwS970dcweGwhTl975 nkGHqh9dm5R+jAv9l/MxTH8V6f7Y82xLBV3Ma3oQ= Date: Mon, 26 Jan 2026 16:24:18 +0100 From: Greg KH To: Xingjing Deng Cc: srini@kernel.org, amahesh@qti.qualcomm.com, arnd@arndb.de, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Xingjing Deng , stable@vger.kernel.org Subject: Re: [PATCH v3] misc: fastrpc: possible double-free of cctx->remote_heap Message-ID: <2026012641-snazzy-upstate-a815@gregkh> References: <20260117140959.879035-1-xjdeng@buaa.edu.cn> Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260117140959.879035-1-xjdeng@buaa.edu.cn> On Sat, Jan 17, 2026 at 10:09:59PM +0800, Xingjing Deng wrote: > fastrpc_init_create_static_process() may free cctx->remote_heap on the > err_map path but does not clear the pointer. Later, fastrpc_rpmsg_remove() > frees cctx->remote_heap again if it is non-NULL, which can lead to a > double-free if the INIT_CREATE_STATIC ioctl hits the error path and the rpmsg > device is subsequently removed/unbound. > Clear cctx->remote_heap after freeing it in the error path to prevent the > later cleanup from freeing it again. > > Fixes: 0871561055e66 ("misc: fastrpc: Add support for audiopd") > Cc: stable@vger.kernel.org # 6.2+ > Signed-off-by: Xingjing Deng > > --- > > v3: > - Adjust the email format. > - Link to v2: https://lore.kernel.org/linux-arm-msm/2026011650-gravitate-happily-5d0c@gregkh/T/#t > > v2: > - Add Fixes: and Cc: stable@vger.kernel.org. > - Link to v1: https://lore.kernel.org/linux-arm-msm/2026011227-casualty-rephrase-9381@gregkh/T/#t > > drivers/misc/fastrpc.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c > index ee652ef01534..fb3b54e05928 100644 > --- a/drivers/misc/fastrpc.c > +++ b/drivers/misc/fastrpc.c > @@ -1370,6 +1370,7 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl, > } > err_map: > fastrpc_buf_free(fl->cctx->remote_heap); > + fl->cctx->remote_heap = NULL; > err_name: > kfree(name); > err: > -- > 2.25.1 > > How was this found and tested? And randomly setting a pointer to null doesn't really document what is happening here, what would you want to see here if you were to look at this code in 5 years? thanks, greg k-h