From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 765D5375AB1; Tue, 18 Aug 2026 18:23:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787077397; cv=none; b=CH+TdTvowzza3RI+wmGP33DssKA8uRLQhFFUlt6A3BmNg4yRucgxH3A+5KydpLA+sIk4IwRivafZyIjP66yWDP4x9uQfMtHLoPjEFIRyiydNbO4rxNj/DICoZkmnyPOLh4DiBbd99jxZMQSnANyn14lCKVJpCTBd/qbyewX2WyI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787077397; c=relaxed/simple; bh=5Evpp+U4fHPOJ5zgWws8ZtPMBLpjNrqaYYN2Yx1XsS8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JryfTTUsvNCl/TFFqEOoefJ9GsFn3tknnukjcCSR8V4ISV/8brm7HRw7Jxq2pMBRucxQO1qak25EIHohRrAbG/yz8WuP+G2s6Djc1hhcE5jXRDRo7KFK2oAuXdh1vyces9Va8kJV+PbW5gsnjTvRchUroNe3JzQ/vaR/69o/YHg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hLU3gu0t; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hLU3gu0t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F3A11F000E9; Tue, 18 Aug 2026 18:23:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787077394; bh=posjS38abV8AgqqIdl+8RlYKAuivtT7vrcQQbTN1Pw0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=hLU3gu0tuKBYVlDMHu3kyJCp+JhY0JDFG3INrpueeDYJ2uQ8l/vFZtKx66q+BbGU7 Ijf4AxMqcSexyXVXtne2b/dJ6DhSJZNGqdE6xDaTP/gDMi4BWF/bEWblACD4JAgW/k bRhEHdYcnyZw7ruen2O0g5auBWmsqlHq5lWNMmnc= Date: Tue, 18 Aug 2026 20:23:10 +0200 From: Greg Kroah-Hartman To: Runyu Xiao Cc: Rui Miguel Silva , Johan Hovold , Alex Elder , Kris Huang , greybus-dev@lists.linaro.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Jianhao Xu Subject: Re: [PATCH] staging: greybus: light: initialize channel lock before registration Message-ID: <2026081801-arguable-gosling-c590@gregkh> References: <20260818142020.1989539-1-runyu.xiao@seu.edu.cn> 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=us-ascii Content-Disposition: inline In-Reply-To: <20260818142020.1989539-1-runyu.xiao@seu.edu.cn> On Tue, Aug 18, 2026 at 10:20:20PM +0800, Runyu Xiao wrote: > gb_lights_light_register() registers each channel before initializing > light->channels[i].lock. Channel registration exposes the LED class > device and its brightness callback, which later takes this mutex. A > concurrent brightness update can therefore hit an uninitialized lock. > > Initialize the channel mutex before registering the channel so the > callback always sees a valid lock. > > Fixes: cc43368a3cde ("greybus: lights: Control runtime pm suspend/resume on AP side") > Cc: stable@vger.kernel.org > Signed-off-by: Runyu Xiao > --- > drivers/staging/greybus/light.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c > index 38c233a706c4..056ef6b0276e 100644 > --- a/drivers/staging/greybus/light.c > +++ b/drivers/staging/greybus/light.c > @@ -1043,11 +1043,11 @@ static int gb_lights_light_register(struct gb_light *light) > * found. > */ > for (i = 0; i < light->channels_count; i++) { > + mutex_init(&light->channels[i].lock); > + > ret = gb_lights_channel_register(&light->channels[i]); > if (ret < 0) > return ret; > - > - mutex_init(&light->channels[i].lock); > } > > light->ready = true; How was this found and tested? thanks, greg k-h