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 --- 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) {