alsa-devel.alsa-project.org archive mirror
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Clemens Ladisch <clemens@ladisch.de>
Cc: alsa-devel@alsa-project.org, kernel-janitors@vger.kernel.org,
	Takashi Iwai <tiwai@suse.com>, Mark Brown <broonie@kernel.org>
Subject: [PATCH] ALSA: fireface: fix info leak in hwdep_read()
Date: Thu, 21 Jan 2021 09:10:47 +0300	[thread overview]
Message-ID: <YAka5xudQNQgRkuC@mwanda> (raw)

If "ff->dev_lock_changed" has not changed and "count" is too large then
this will copy data beyond the end of the struct to user space.

Fixes: f656edd5fb33 ("ALSA: fireface: add hwdep interface")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 sound/firewire/fireface/ff-hwdep.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/firewire/fireface/ff-hwdep.c b/sound/firewire/fireface/ff-hwdep.c
index 4b2e0dff5ddb..b84dde609a03 100644
--- a/sound/firewire/fireface/ff-hwdep.c
+++ b/sound/firewire/fireface/ff-hwdep.c
@@ -35,12 +35,12 @@ static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
 	}
 
 	memset(&event, 0, sizeof(event));
+	count = min_t(long, count, sizeof(event.lock_status));
 	if (ff->dev_lock_changed) {
 		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
 		event.lock_status.status = (ff->dev_lock_count > 0);
 		ff->dev_lock_changed = false;
 
-		count = min_t(long, count, sizeof(event.lock_status));
 	}
 
 	spin_unlock_irq(&ff->lock);
-- 
2.29.2


             reply	other threads:[~2021-01-21  6:13 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-21  6:10 Dan Carpenter [this message]
2021-01-21 20:42 ` [PATCH] ALSA: fireface: fix info leak in hwdep_read() Christophe JAILLET
2021-01-22  7:13   ` Dan Carpenter
2021-01-25 11:12     ` [PATCH v2 1/2] ALSA: oxfw: remove an unnecessary condition " Dan Carpenter
2021-01-25 13:46       ` Takashi Sakamoto
2021-01-25 13:51       ` Takashi Iwai
2021-01-25 11:13     ` [PATCH v2 2/2] ALSA: fireface: remove " Dan Carpenter
2021-01-25 13:45       ` Takashi Sakamoto
2021-01-25 13:51       ` Takashi Iwai

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YAka5xudQNQgRkuC@mwanda \
    --to=dan.carpenter@oracle.com \
    --cc=alsa-devel@alsa-project.org \
    --cc=broonie@kernel.org \
    --cc=clemens@ladisch.de \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=tiwai@suse.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).