]> www.infradead.org Git - users/jedix/linux-maple.git/commit
ALSA: pcm: Fix potential Spectre v1 vulnerability
authorGustavo A. R. Silva <gustavo@embeddedor.com>
Wed, 12 Dec 2018 21:36:28 +0000 (15:36 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 9 Jan 2019 16:14:46 +0000 (17:14 +0100)
commitbbf036122f6400396febc4e545dc24ebf35fa341
tree684ae78196305003b3bf71cc1b6c57931479f947
parentc4d65a3afd071608e1b9b86112a4f0cf01932e4d
ALSA: pcm: Fix potential Spectre v1 vulnerability

commit 94ffb030b6d31ec840bb811be455dd2e26a4f43e upstream.

stream 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/pcm.c:140 snd_pcm_control_ioctl() warn: potential spectre issue 'pcm->streams' [r] (local cap)

Fix this by sanitizing stream before using it to index pcm->streams

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

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: stable@vger.kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sound/core/pcm.c