Commit 027a9fe6 authored Oct 30, 2016 by Takashi Iwai

ALSA: info: Limit the proc text input size



The ALSA proc handler allows currently the write in the unlimited size
until kmalloc() fails.  But basically the write is supposed to be only
for small inputs, mostly for one line inputs, and we don't have to
handle too large sizes at all.  Since the kmalloc error results in the
kernel warning, it's better to limit the size beforehand.

This patch adds the limit of 16kB, which must be large enough for the
currently existing code.

Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent f8f93bc9

sound/core/info.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -329,6 +329,9 @@ static ssize_t snd_info_text_entry_write(struct file *file,
		if (!valid_pos(pos, count))
		return -EIO;
		next = pos + count;
		/* don't handle too large text inputs */
		if (next > 16 * 1024)
		return -EIO;
		mutex_lock(&entry->access);
		buf = data->wbuffer;
		if (!buf) {

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