From: Prasad J Pandit <p...@fedoraproject.org> The 53C9X Fast SCSI Controller(FSC) comes with internal 16-byte FIFO buffers. One is used to handle commands and other is for information transfer. While reading/writing to these buffers an index into 's->ti_buf[TI_BUFSZ=16]' could exceed its size, as a check was missing to validate it. Add check to avoid OOB r/w access.
Reported-by: Huawei PSIRT <ps...@huawei.com> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> --- hw/scsi/esp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 591c817..80e4287 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -407,8 +407,10 @@ uint64_t esp_reg_read(ESPState *s, uint32_t saddr) qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n"); s->rregs[ESP_FIFO] = 0; - } else { + } else if (s->ti_rptr < TI_BUFSZ) { s->rregs[ESP_FIFO] = s->ti_buf[s->ti_rptr++]; + } else { + trace_esp_error_fifo_overrun(); } esp_raise_irq(s); } @@ -456,7 +458,7 @@ void esp_reg_write(ESPState *s, uint32_t saddr, uint64_t val) } else { trace_esp_error_fifo_overrun(); } - } else if (s->ti_size == TI_BUFSZ - 1) { + } else if (s->ti_wptr == TI_BUFSZ - 1) { trace_esp_error_fifo_overrun(); } else { s->ti_size++; -- 2.5.5