From: Takashi Iwai <tiwai@suse.de>
To: linux-acpi@vger.kernel.org
Cc: Zhang Rui <rui.zhang@intel.com>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>
Subject: [PATCH] ACPI: fan: Use scnprintf() for avoiding potential buffer overflow
Date: Wed, 11 Mar 2020 08:08:51 +0100 [thread overview]
Message-ID: <20200311070851.3731-1-tiwai@suse.de> (raw)
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().
Also adjust the argument to really match with the actually remaining
buffer size.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
drivers/acpi/fan.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/acpi/fan.c b/drivers/acpi/fan.c
index aaf4e8f348cf..873e039ad4b7 100644
--- a/drivers/acpi/fan.c
+++ b/drivers/acpi/fan.c
@@ -276,29 +276,29 @@ static ssize_t show_state(struct device *dev, struct device_attribute *attr, cha
int count;
if (fps->control == 0xFFFFFFFF || fps->control > 100)
- count = snprintf(buf, PAGE_SIZE, "not-defined:");
+ count = scnprintf(buf, PAGE_SIZE, "not-defined:");
else
- count = snprintf(buf, PAGE_SIZE, "%lld:", fps->control);
+ count = scnprintf(buf, PAGE_SIZE, "%lld:", fps->control);
if (fps->trip_point == 0xFFFFFFFF || fps->trip_point > 9)
- count += snprintf(&buf[count], PAGE_SIZE, "not-defined:");
+ count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined:");
else
- count += snprintf(&buf[count], PAGE_SIZE, "%lld:", fps->trip_point);
+ count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld:", fps->trip_point);
if (fps->speed == 0xFFFFFFFF)
- count += snprintf(&buf[count], PAGE_SIZE, "not-defined:");
+ count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined:");
else
- count += snprintf(&buf[count], PAGE_SIZE, "%lld:", fps->speed);
+ count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld:", fps->speed);
if (fps->noise_level == 0xFFFFFFFF)
- count += snprintf(&buf[count], PAGE_SIZE, "not-defined:");
+ count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined:");
else
- count += snprintf(&buf[count], PAGE_SIZE, "%lld:", fps->noise_level * 100);
+ count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld:", fps->noise_level * 100);
if (fps->power == 0xFFFFFFFF)
- count += snprintf(&buf[count], PAGE_SIZE, "not-defined\n");
+ count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined\n");
else
- count += snprintf(&buf[count], PAGE_SIZE, "%lld\n", fps->power);
+ count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld\n", fps->power);
return count;
}
--
2.16.4
next reply other threads:[~2020-03-11 7:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 7:08 Takashi Iwai [this message]
2020-03-14 10:13 ` [PATCH] ACPI: fan: Use scnprintf() for avoiding potential buffer overflow Rafael J. Wysocki
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