Re: [PATCH 187/190] Revert "ALSA: control: fix a redundant-copy issue"

Takashi Iwai
2021-04-21T16:30:45Z

On Wed, 21 Apr 2021 15:01:02 +0200,
Greg Kroah-Hartman wrote:
>
> This reverts commit 3f12888dfae2a48741c4caa9214885b3aaf350f9.
>
> 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: Wenwen Wang <wang6495@umn.edu>
> Cc: <stable@vger.kernel.org>
> Cc: Takashi Iwai <tiwai@suse.de>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This one is, unlike other patches I've been involved with, about the
ALSA core code, and this change is likely worth to keep.

The code change is correct, and even though it's really a minor issue,
an optimization is right.

thanks,

Takashi

> ---
> sound/core/control_compat.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/sound/core/control_compat.c b/sound/core/control_compat.c
> index 1d708aab9c98..857acf83ae47 100644
> --- a/sound/core/control_compat.c
> +++ b/sound/core/control_compat.c
> @@ -381,7 +381,8 @@ static int snd_ctl_elem_add_compat(struct snd_ctl_file *file,
> if (copy_from_user(&data->id, &data32->id, sizeof(data->id)) ||
> copy_from_user(&data->type, &data32->type, 3 * sizeof(u32)))
> goto error;
> - if (get_user(data->owner, &data32->owner))
> + if (get_user(data->owner, &data32->owner) ||
> + get_user(data->type, &data32->type))
> goto error;
> switch (data->type) {
> case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
> --
> 2.31.1
>