Re: [alsa-devel] [PATCH] rawmidi: virtual: fix reading into a small buffer

19 Mar 2017

Hi,
On Mar 19 2017 07:10, Clemens Ladisch wrote:
...
In the special case for handling partial messages, the pointer
calculations were wrong, which would result in data corruption.
Signed-off-by: Clemens Ladisch clemens@ladisch.de
Reviewd-by: Takashi Sakamoto o-takashi@sakamocchi.jp
...

--- alsa-lib/src/rawmidi/rawmidi_virt.c
+++ alsa-lib/src/rawmidi/rawmidi_virt.c
@@ -263,8 +263,8 @@ static ssize_t snd_rawmidi_virtual_read(snd_rawmidi_t *rmidi, void *buffer, size
   	}
   	size1 = virt->in_buf_size - virt->in_buf_ofs;
   	if ((size_t)size1 > size) {

	virt->in_buf_ofs += size1 - size;


	memcpy(buffer, virt->in_buf_ptr, size);




	memcpy(buffer, virt->in_buf_ptr + virt->in_buf_ofs, size);


	virt->in_buf_ofs += size;
result += size;
break;

}

Regards
Takashi Sakamoto

    