[alsa-devel] [PATCH 0/2] ALSA: dice: fix a fatal bug when no sound card is registered

[Takashi Sakamoto]

Hi,

On Mar 26 2016 21:05, Takashi Sakamoto wrote:
> Hi,
> 
> This patchset is for Linux 4.6-rc2.
> 
> ALSA dice driver causes kernel NULL pointer dereference in a case that
> no sound card instance is registered and unit is going to be removed.
> This is observed when dice-based units are connected to Linux system and
> disconnected within 2 seconds, thus it's rare.
> 
> Additionally, even if the bug is fixed, the driver dumps warnings for
> most dice-based models which supports a pair of isochronous streams.
> This can occur regardless of the former bug. Users can see this for
> unsupported dice-based models.
> 
> This patchset fixes these bugs.

I realized that this patchset is not proper to Linux 4.6-rc2. The stream
data is confirmed to initialized in unit probe callback, and safely
released when releasing private data. I worked on the other branch and
had a confusion. So please drop this.

However, current ALSA dice driver has a bug not to release stream data
when releasing private data. This causes memory leak and should be fixed
in 4.6-rc2. I'll post a patch for the bug soon.

(I'd like to get the reason I often realize such mistakes just after
getting up in the morning, the beginning of a day, sign...)


Regards

Takashi Sakamoto

> Takashi Sakamoto (2):
>   ALSA: dice: fix NULL pointer dereference at remove units when sound
>     card is not registered
>   ALSA: firewire-lib: skip releasing stream data when it's not
>     initialized
> 
>  sound/firewire/amdtp-stream.c     |  4 ++++
>  sound/firewire/dice/dice-stream.c | 14 ++++----------
>  2 files changed, 8 insertions(+), 10 deletions(-)
>