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From: Takashi Iwai <tiwai@suse.de>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>, linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/2] drivers/base/cpu: Use scnprintf() for avoiding potential buffer overflow
Date: Wed, 11 Mar 2020 09:02:06 +0100	[thread overview]
Message-ID: <20200311080207.12046-2-tiwai@suse.de> (raw)
In-Reply-To: <20200311080207.12046-1-tiwai@suse.de>

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/base/cpu.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 6265871a4af2..67aaa052c7a2 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -258,13 +258,13 @@ static ssize_t print_cpus_offline(struct device *dev,
 			buf[n++] = ',';
 
 		if (nr_cpu_ids == total_cpus-1)
-			n += snprintf(&buf[n], len - n, "%u", nr_cpu_ids);
+			n += scnprintf(&buf[n], len - n, "%u", nr_cpu_ids);
 		else
-			n += snprintf(&buf[n], len - n, "%u-%d",
+			n += scnprintf(&buf[n], len - n, "%u-%d",
 						      nr_cpu_ids, total_cpus-1);
 	}
 
-	n += snprintf(&buf[n], len - n, "\n");
+	n += scnprintf(&buf[n], len - n, "\n");
 	return n;
 }
 static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
-- 
2.16.4


  reply	other threads:[~2020-03-11  8:02 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-11  8:02 [PATCH v2 0/2] drivers/base/cpu: s*nprintf() usage fixes / cleanups Takashi Iwai
2020-03-11  8:02 ` Takashi Iwai [this message]
2020-03-11  8:02 ` [PATCH v2 2/2] drivers/base/cpu: Simplify s*nprintf() usages Takashi Iwai
2020-03-11  8:06 ` [PATCH v2 0/2] drivers/base/cpu: s*nprintf() usage fixes / cleanups Greg Kroah-Hartman

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