Re: [PATCH 131/190] Revert "net: 8390: fix potential NULL pointer dereferences"

[Greg Kroah-Hartman]

On Wed, Apr 21, 2021 at 03:00:06PM +0200, Greg Kroah-Hartman wrote:
> This reverts commit c7cbc3e937b885c9394bf9d0ca21ceb75c2ac262.
> 
> 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/8390/pcnet_cs.c | 10 ----------
>  1 file changed, 10 deletions(-)
> 
> diff --git a/drivers/net/ethernet/8390/pcnet_cs.c b/drivers/net/ethernet/8390/pcnet_cs.c
> index 9d3b1e0e425c..0a408fa2b7a4 100644
> --- a/drivers/net/ethernet/8390/pcnet_cs.c
> +++ b/drivers/net/ethernet/8390/pcnet_cs.c
> @@ -289,11 +289,6 @@ static struct hw_info *get_hwinfo(struct pcmcia_device *link)
>  
>      virt = ioremap(link->resource[2]->start,
>  	    resource_size(link->resource[2]));
> -    if (unlikely(!virt)) {
> -	    pcmcia_release_window(link, link->resource[2]);
> -	    return NULL;
> -    }
> -
>      for (i = 0; i < NR_INFO; i++) {
>  	pcmcia_map_mem_page(link, link->resource[2],
>  		hw_info[i].offset & ~(resource_size(link->resource[2])-1));
> @@ -1430,11 +1425,6 @@ static int setup_shmem_window(struct pcmcia_device *link, int start_pg,
>      /* Try scribbling on the buffer */
>      info->base = ioremap(link->resource[3]->start,
>  			resource_size(link->resource[3]));
> -    if (unlikely(!info->base)) {
> -	    ret = -ENOMEM;
> -	    goto failed;
> -    }
> -
>      for (i = 0; i < (TX_PAGES<<8); i += 2)
>  	__raw_writew((i>>1), info->base+offset+i);
>      udelay(100);
> -- 
> 2.31.1
> 

This change causes a memory leak on the error path, so I will keep the
revert.

But really, a pcmcia card with a failed ioremap() call?  That can never
happen here, so I'll just keep it reverted, it's not worth touching
again.

thanks,

greg k-h