Re: [PATCH] ALSA: isa/wavefront: Fix potential Spectre v1 vulnerabilities

[Takashi Iwai <tiwai@suse.de>]

On Thu, 20 Dec 2018 00:31:43 +0100,
 Gustavo A. R. Silva  wrote:
> 
> header->number 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/isa/wavefront/wavefront_synth.c:792 wavefront_send_patch() warn: potential spectre issue 'dev->patch_status' [w] (local cap)
> sound/isa/wavefront/wavefront_synth.c:819 wavefront_send_program() warn: potential spectre issue 'dev->prog_status' [w] (local cap)
> sound/isa/wavefront/wavefront_synth.c:1197 wavefront_send_alias() warn: potential spectre issue 'dev->sample_status' [w]
> sound/isa/wavefront/wavefront_synth.c:1248 wavefront_send_multisample() warn: potential spectre issue 'dev->sample_status' [w]
> sound/isa/wavefront/wavefront_synth.c:1548 wavefront_synth_control() warn: potential spectre issue 'dev->sample_status' [r] (local cap)
> 
> Fix this by sanitizing header->number before using it to index
> dev->patch_status, dev->prog_status and dev->sample_status.
> 
> 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://marc.info/?l=linux-kernel&m=152449131114778&w=2
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Is there any platform with ISA slot that suffers from Spectre?


thanks,

Takashi