Re: [PATCH 077/190] Revert "rapidio: fix a NULL pointer dereference when create_workqueue() fails"

[Greg Kroah-Hartman]

On Wed, Apr 21, 2021 at 02:59:12PM +0200, Greg Kroah-Hartman wrote:
> This reverts commit 23015b22e47c5409620b1726a677d69e5cd032ba.
> 
> Commits from @umn.edu addresses have been found to be submitted in "bad
> faith" to try to test the kernel community's ability to review "known
> malicious" changes.  The result of these submissions can be found in a
> paper published at the 42nd IEEE Symposium on Security and Privacy
> entitled, "Open Source Insecurity: Stealthily Introducing
> Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> of Minnesota) and Kangjie Lu (University of Minnesota).
> 
> Because of this, all submissions from this group must be reverted from
> the kernel tree and will need to be re-reviewed again to determine if
> they actually are a valid fix.  Until that work is complete, remove this
> change to ensure that no problems are being introduced into the
> codebase.
> 
> Cc: Kangjie Lu <kjlu@xxxxxxx>
> Cc: Alexandre Bounine <alex.bou9@xxxxxxxxx>
> Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/rapidio/rio_cm.c | 8 --------
>  1 file changed, 8 deletions(-)
> 
> diff --git a/drivers/rapidio/rio_cm.c b/drivers/rapidio/rio_cm.c
> index 50ec53d67a4c..e6c16f04f2b4 100644
> --- a/drivers/rapidio/rio_cm.c
> +++ b/drivers/rapidio/rio_cm.c
> @@ -2138,14 +2138,6 @@ static int riocm_add_mport(struct device *dev,
>  	mutex_init(&cm->rx_lock);
>  	riocm_rx_fill(cm, RIOCM_RX_RING_SIZE);
>  	cm->rx_wq = create_workqueue(DRV_NAME "/rxq");
> -	if (!cm->rx_wq) {
> -		riocm_error("failed to allocate IBMBOX_%d on %s",
> -			    cmbox, mport->name);
> -		rio_release_outb_mbox(mport, cmbox);
> -		kfree(cm);
> -		return -ENOMEM;
> -	}
> -
>  	INIT_WORK(&cm->rx_work, rio_ibmsg_handler);
>  
>  	cm->tx_slot = 0;
> -- 
> 2.31.1
> 

This patch has a memory leak on the error path here, it does not clean
up everything properly.  So I'll keep the revert and fix it up properly
in a follow-on patch.

thanks,

greg k-h