Commit 4636a046 authored Mar 11, 2020 by Takashi Iwai Committed by Greg Kroah-Hartman Mar 11, 2020

drivers/base/cpu: Use scnprintf() for avoiding potential buffer overflow



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>
Link: https://lore.kernel.org/r/20200311080207.12046-2-tiwai@suse.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 9a2dd570

drivers/base/cpu.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -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);

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