Re: [PATCH 127/190] Revert "ALSA: sb8: add a check for request_region"

[Takashi Iwai]

On Wed, 21 Apr 2021 15:00:02 +0200,
Greg Kroah-Hartman wrote:
> 
> This reverts commit dcd0feac9bab901d5739de51b3f69840851f8919.
> 
> 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: Takashi Iwai <tiwai@xxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

This code change itself looks OK, OTOH, the original commit message is
slightly wrong: the code path can never result in NULL deference in
this case, as it's just an optional resource reservation.  So, it's
safe to revert this.


thanks,

Takashi

> ---
>  sound/isa/sb/sb8.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/sound/isa/sb/sb8.c b/sound/isa/sb/sb8.c
> index 6c9d534ce8b6..95290ffe5c6e 100644
> --- a/sound/isa/sb/sb8.c
> +++ b/sound/isa/sb/sb8.c
> @@ -95,10 +95,6 @@ static int snd_sb8_probe(struct device *pdev, unsigned int dev)
>  
>  	/* block the 0x388 port to avoid PnP conflicts */
>  	acard->fm_res = request_region(0x388, 4, "SoundBlaster FM");
> -	if (!acard->fm_res) {
> -		err = -EBUSY;
> -		goto _err;
> -	}
>  
>  	if (port[dev] != SNDRV_AUTO_PORT) {
>  		if ((err = snd_sbdsp_create(card, port[dev], irq[dev],
> -- 
> 2.31.1
>