Kernel-Janitors Archive on lore.kernel.org
 help / color / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Clemens Ladisch <clemens@ladisch.de>,
	Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: alsa-devel@alsa-project.org, kernel-janitors@vger.kernel.org,
	Takashi Iwai <tiwai@suse.com>
Subject: [PATCH] ALSA: bebob: potential info leak in hwdep_read()
Date: Wed, 07 Oct 2020 07:49:28 +0000
Message-ID: <20201007074928.GA2529578@mwanda> (raw)

The "count" variable needs to be capped on every path so that we don't
copy too much information to the user.

Fixes: 618eabeae711 ("ALSA: bebob: Add hwdep interface")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 sound/firewire/bebob/bebob_hwdep.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/sound/firewire/bebob/bebob_hwdep.c b/sound/firewire/bebob/bebob_hwdep.c
index 45b740f44c45..c362eb38ab90 100644
--- a/sound/firewire/bebob/bebob_hwdep.c
+++ b/sound/firewire/bebob/bebob_hwdep.c
@@ -36,12 +36,11 @@ 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 (bebob->dev_lock_changed) {
 		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
 		event.lock_status.status = (bebob->dev_lock_count > 0);
 		bebob->dev_lock_changed = false;
-
-		count = min_t(long, count, sizeof(event.lock_status));
 	}
 
 	spin_unlock_irq(&bebob->lock);
-- 
2.28.0

             reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-07  7:49 Dan Carpenter [this message]
2020-10-07 13:04 ` Takashi Sakamoto
2020-10-07 15:23   ` Takashi Sakamoto
2020-10-07 15:34 ` 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=20201007074928.GA2529578@mwanda \
    --to=dan.carpenter@oracle.com \
    --cc=alsa-devel@alsa-project.org \
    --cc=clemens@ladisch.de \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=o-takashi@sakamocchi.jp \
    --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

Kernel-Janitors Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/kernel-janitors/0 kernel-janitors/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 kernel-janitors kernel-janitors/ https://lore.kernel.org/kernel-janitors \
		kernel-janitors@vger.kernel.org
	public-inbox-index kernel-janitors

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.kernel-janitors


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git