linux-kernel - [PATCH][next] ALSA: vmaster: Use flex_array

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200729221829.GA10623@embeddedor>
Date:   Wed, 29 Jul 2020 17:18:29 -0500
From:   "Gustavo A. R. Silva" <gustavoars@...nel.org>
To:     Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>
Cc:     alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        "Gustavo A. R. Silva" <gustavoars@...nel.org>
Subject: [PATCH][next] ALSA: vmaster: Use flex_array_size() helper in memcpy()

Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.

This helper offers defense-in-depth against potential integer overflows
and makes it explicitly clear that we are dealing with a flexible array
member.

Signed-off-by: Gustavo A. R. Silva <gustavoars@...nel.org>
---
 sound/core/vmaster.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c
index ab36f9898711..21ce4082cb5f 100644
--- a/sound/core/vmaster.c
+++ b/sound/core/vmaster.c
@@ -262,7 +262,8 @@ int _snd_ctl_add_follower(struct snd_kcontrol *master,
 		return -ENOMEM;
 	srec->kctl = follower;
 	srec->follower = *follower;
-	memcpy(srec->follower.vd, follower->vd, follower->count * sizeof(*follower->vd));
+	memcpy(srec->follower.vd, follower->vd, flex_array_size(srec, follower.vd,
+								srec->follower.count));
 	srec->master = master_link;
 	srec->flags = flags;
 
-- 
2.27.0