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-ayl...@ilande.co.uk> Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org> Tested-by: Alexander Bulekov <alx...@bu.edu> Message-Id: <20210407195801.685-10-mark.cave-ayl...@ilande.co.uk> --- hw/scsi/esp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 9d3fdb4398..a26a109166 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -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 { -- 2.20.1