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[Qemu-devel] [PATCH] scsi: esp: check TI buffer index before read/write
From: |
P J P |
Subject: |
[Qemu-devel] [PATCH] scsi: esp: check TI buffer index before read/write |
Date: |
Tue, 31 May 2016 00:28:48 +0530 |
From: Prasad J Pandit <address@hidden>
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 <address@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
---
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
- [Qemu-devel] [PATCH] scsi: esp: check TI buffer index before read/write,
P J P <=