Commit 81396266 authored by Stefan Weil's avatar Stefan Weil Committed by Stefan Hajnoczi
Browse files

lm4549: Fix buffer overflow 



Report from smatch:
lm4549.c:234 lm4549_write_samples(14) error:
 buffer overflow 's->buffer' 1024 <= 1024

There must be enough space to add two entries starting with index
s->buffer_level, therefore the old check was wrong.

[Peter Maydell <peter.maydell@linaro.org> clarifies the nature of the
analyser warning:

I don't object to making the change to placate the analyser,
but I don't think this is actually a buffer overrun. We always
add and remove samples from the buffer two at a time, so it's
not possible to get here with s->buffer_level == BUFFER_SIZE-1
(which is the only case where the old and new conditions
give different answers).]

Signed-off-by: default avatarStefan Weil <sw@weilnetz.de>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@gmail.com>
parent 5d40097f

hw/lm4549.c

+1 −1
Original line number Diff line number Diff line
@@ -224,7 +224,7 @@ uint32_t lm4549_write_samples(lm4549_state *s, uint32_t left, uint32_t right) 
       This model supports 16-bit playback.

    */



    if (s->buffer_level >= LM4549_BUFFER_SIZE) {

    if (s->buffer_level > LM4549_BUFFER_SIZE - 2) {

        DPRINTF("write_sample Buffer full\n");

        return 0;

    }