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From: Dan Carpenter <error27@gmail.com>
To: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: alsa-devel@alsa-project.org, Jassi Brar <jassi.brar@samsung.com>,
	Takashi Iwai <tiwai@suse.de>,
	kernel-janitors@vger.kernel.org,
	Mark Brown <broonie@opensource.wolfsonmicro.com>,
	Peter Ujfalusi <peter.ujfalusi@nokia.com>
Subject: [patch] ASoC: soc: snprintf() doesn't return negative
Date: Mon, 11 Oct 2010 03:54:17 +0000	[thread overview]
Message-ID: <20101011035416.GD5851@bicker> (raw)

In user space snprintf() returns negative on errors but the kernel
version only returns positives.  It could potentially return sizes
larger than the size of the buffer so we should check for that.

Signed-off-by: Dan Carpenter <error27@gmail.com>

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 8751efd..8da307b 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -284,8 +284,10 @@ static ssize_t codec_list_read_file(struct file *file, char __user *user_buf,
 		ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s\n",
 				codec->name);
 
-	if (ret >= 0)
-		ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+	if (ret > PAGE_SIZE)
+		ret = PAGE_SIZE;
+
+	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
 
 	kfree(buf);
 
@@ -310,8 +312,10 @@ static ssize_t dai_list_read_file(struct file *file, char __user *user_buf,
 	list_for_each_entry(dai, &dai_list, list)
 		ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s\n", dai->name);
 
-	if (ret >= 0)
-		ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+	if (ret > PAGE_SIZE)
+		ret = PAGE_SIZE;
+
+	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
 
 	kfree(buf);
 
@@ -338,8 +342,10 @@ static ssize_t platform_list_read_file(struct file *file,
 		ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s\n",
 				platform->name);
 
-	if (ret >= 0)
-		ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+	if (ret > PAGE_SIZE)
+		ret = PAGE_SIZE;
+
+	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
 
 	kfree(buf);
 

             reply	other threads:[~2010-10-11  3:54 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-11  3:54 Dan Carpenter [this message]
2010-10-11 10:07 ` [patch] ASoC: soc: snprintf() doesn't return negative Liam Girdwood
2010-10-11 10:40 ` Mark Brown
2010-10-11 16:40   ` Dan Carpenter
2010-10-11 18:51     ` Mark Brown
2010-10-11 19:45       ` Dan Carpenter
2010-10-11 20:57         ` Takashi Iwai
2010-10-12  9:35           ` Mark Brown
2010-10-12  9:49             ` Takashi Iwai
2010-10-12  9:56               ` Mark Brown
2010-10-12 10:40                 ` Dan Carpenter
2010-10-11 21:11         ` Dan Carpenter

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