From 0a3313062b30332c750fa5ac69ad85d6d12fda3c Mon Sep 17 00:00:00 2001 From: Stefan Weil Date: Sat, 1 Sep 2012 12:43:41 +0200 Subject: [PATCH] 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 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: Stefan Weil Signed-off-by: Stefan Hajnoczi (cherry picked from commit 8139626643cbe8dc07bd9acc88057effeedf8064) Signed-off-by: Michael Roth --- hw/lm4549.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/lm4549.c b/hw/lm4549.c index 80b3ec4..e0137d5 100644 --- a/hw/lm4549.c +++ b/hw/lm4549.c @@ -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; }