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

Takashi Iwai
2021-04-21T16:21:55Z

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@umn.edu>
> Cc: Takashi Iwai <tiwai@suse.de>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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
>