Re: [PATCH] ALSA: seq: oss: Fix Spectre v1 vulnerability

[Takashi Iwai]

On Thu, 21 Mar 2019 00:42:01 +0100,
 Gustavo A. R. Silva  wrote:
> 
> dev is indirectly controlled by user-space, hence leading to
> a potential exploitation of the Spectre variant 1 vulnerability.
> 
> This issue was detected with the help of Smatch:
> 
> sound/core/seq/oss/seq_oss_synth.c:626 snd_seq_oss_synth_make_info() warn: potential spectre issue 'dp->synths' [w] (local cap)
> 
> Fix this by sanitizing dev before using it to index dp->synths.
> 
> Notice that given that speculation windows are large, the policy is
> to kill the speculation on the first load and not worry if it can be
> completed with a dependent load/store [1].
> 
> [1] https://lore.kernel.org/lkml/20180423164740.GY17484@xxxxxxxxxxxxxx/
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

Applied, thanks.


Takashi