From 027a9fe6835620422b6713892175716f3613dd9d Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Sun, 30 Oct 2016 22:18:45 +0100 Subject: [PATCH] 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 --- sound/core/info.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sound/core/info.c b/sound/core/info.c index 895362a696c9..291d6ed80d80 100644 --- a/sound/core/info.c +++ b/sound/core/info.c @@ -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) { -- 2.20.1