linux-kernel - RE: [PATCH] remoteproc: imx_dsp_rproc: Add mutex protection for workqueue

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <DU0PR04MB9417A858260FFB3E0A00CC1788549@DU0PR04MB9417.eurprd04.prod.outlook.com>
Date:   Wed, 28 Sep 2022 10:22:32 +0000
From:   Peng Fan <peng.fan@....com>
To:     "S.J. Wang" <shengjiu.wang@....com>,
        "andersson@...nel.org" <andersson@...nel.org>,
        "mathieu.poirier@...aro.org" <mathieu.poirier@...aro.org>,
        "arnaud.pouliquen@...s.st.com" <arnaud.pouliquen@...s.st.com>
CC:     "linux-remoteproc@...r.kernel.org" <linux-remoteproc@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "shengjiu.wang@...il.com" <shengjiu.wang@...il.com>
Subject: RE: [PATCH] remoteproc: imx_dsp_rproc: Add mutex protection for
 workqueue

> Subject: [PATCH] remoteproc: imx_dsp_rproc: Add mutex protection for
> workqueue
> 
> The workqueue may execute late even after remoteproc is stopped or
> stopping, some resources (rpmsg device and endpoint) have been released
> in rproc_stop_subdevices(), then rproc_vq_interrupt() access these
> resources will cause kennel dump.
> 
> Call trace:
>  virtqueue_add_split+0x1ac/0x560
>  virtqueue_add_inbuf+0x4c/0x60
>  rpmsg_recv_done+0x15c/0x294
>  vring_interrupt+0x6c/0xa4
>  rproc_vq_interrupt+0x30/0x50
>  imx_dsp_rproc_vq_work+0x24/0x40 [imx_dsp_rproc]
>  process_one_work+0x1d0/0x354
>  worker_thread+0x13c/0x470
>  kthread+0x154/0x160
>  ret_from_fork+0x10/0x20
> 
> Add mutex protection in imx_dsp_rproc_vq_work(), if the state is not
> running, then just skip calling rproc_vq_interrupt().
> 
> Also the flush workqueue operation can't be added in rproc stop for same
> reason.
> 
> Fixes: ec0e5549f358 ("remoteproc: imx_dsp_rproc: Add remoteproc driver
> for DSP on i.MX")
> Signed-off-by: Shengjiu Wang <shengjiu.wang@....com>

Reviewed-by: Peng Fan <peng.fan@....com>

I also give a look at other drivers, seems almost all drivers use rproc_vq_interrupt
has same issue, should use mutex to protect the mbox rx callback.

Regards,
Peng.

> ---
>  drivers/remoteproc/imx_dsp_rproc.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/remoteproc/imx_dsp_rproc.c
> b/drivers/remoteproc/imx_dsp_rproc.c
> index 899aa8dd12f0..95da1cbefacf 100644
> --- a/drivers/remoteproc/imx_dsp_rproc.c
> +++ b/drivers/remoteproc/imx_dsp_rproc.c
> @@ -347,9 +347,6 @@ static int imx_dsp_rproc_stop(struct rproc *rproc)
>  	struct device *dev = rproc->dev.parent;
>  	int ret = 0;
> 
> -	/* Make sure work is finished */
> -	flush_work(&priv->rproc_work);
> -
>  	if (rproc->state == RPROC_CRASHED) {
>  		priv->flags &= ~REMOTE_IS_READY;
>  		return 0;
> @@ -432,9 +429,18 @@ static void imx_dsp_rproc_vq_work(struct
> work_struct *work)  {
>  	struct imx_dsp_rproc *priv = container_of(work, struct
> imx_dsp_rproc,
>  						  rproc_work);
> +	struct rproc *rproc = priv->rproc;
> +
> +	mutex_lock(&rproc->lock);
> +
> +	if (rproc->state != RPROC_RUNNING)
> +		goto unlock_mutex;
> 
>  	rproc_vq_interrupt(priv->rproc, 0);
>  	rproc_vq_interrupt(priv->rproc, 1);
> +
> +unlock_mutex:
> +	mutex_unlock(&rproc->lock);
>  }
> 
>  /**
> --
> 2.34.1