esp: don't overflow cmdfifo if TC is larger than the cmdfifo size

If a guest transfers the message out/command phase data using DMA with a TC
that is larger than the cmdfifo size then the cmdfifo overflows triggering
an assert. Limit the size of the transfer to the free space available in
cmdfifo.

Buglink: https://bugs.launchpad.net/qemu/+bug/1919036
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Alexander Bulekov <alxndr@bu.edu>
Message-Id: <20210407195801.685-10-mark.cave-ayland@ilande.co.uk>
This commit is contained in:
Mark Cave-Ayland 2021-04-07 20:57:58 +01:00
parent fbc6510e33
commit 0ebb5fd805
1 changed files with 1 additions and 0 deletions

View File

@ -578,6 +578,7 @@ static void esp_do_dma(ESPState *s)
cmdlen = fifo8_num_used(&s->cmdfifo);
trace_esp_do_dma(cmdlen, len);
if (s->dma_memory_read) {
len = MIN(len, fifo8_num_free(&s->cmdfifo));
s->dma_memory_read(s->dma_opaque, buf, len);
fifo8_push_all(&s->cmdfifo, buf, len);
} else {