Re: [PATCH 135/190] Revert "net: rocker: fix a potential NULL pointer dereference"

[Greg Kroah-Hartman]

On Wed, Apr 21, 2021 at 03:00:10PM +0200, Greg Kroah-Hartman wrote:
> This reverts commit 5c149314d91876f743ee43efd75b6287ec55480e.
> 
> 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: David S. Miller <davem@xxxxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/net/ethernet/rocker/rocker_main.c | 5 -----
>  1 file changed, 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/rocker/rocker_main.c b/drivers/net/ethernet/rocker/rocker_main.c
> index 3473d296b2e2..a9c654b885de 100644
> --- a/drivers/net/ethernet/rocker/rocker_main.c
> +++ b/drivers/net/ethernet/rocker/rocker_main.c
> @@ -2791,11 +2791,6 @@ static int rocker_switchdev_event(struct notifier_block *unused,
>  		memcpy(&switchdev_work->fdb_info, ptr,
>  		       sizeof(switchdev_work->fdb_info));
>  		switchdev_work->fdb_info.addr = kzalloc(ETH_ALEN, GFP_ATOMIC);
> -		if (unlikely(!switchdev_work->fdb_info.addr)) {
> -			kfree(switchdev_work);
> -			return NOTIFY_BAD;
> -		}
> -
>  		ether_addr_copy((u8 *)switchdev_work->fdb_info.addr,
>  				fdb_info->addr);
>  		/* Take a reference on the rocker device */
> -- 
> 2.31.1
> 

The unlikely() here is not needed at all, but the logic in the cleanup
looks correct so I'll drop this revert.

greg k-h