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[Qemu-devel] [PULL 04/11] scsi: esp: check TI buffer index before read/w
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 04/11] scsi: esp: check TI buffer index before read/write |
Date: |
Mon, 6 Jun 2016 19:35:13 +0200 |
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. Three control variables 'ti_rptr',
'ti_wptr' and 'ti_size' are used to control r/w access to the
information transfer buffer ti_buf[TI_BUFSZ=16]. In that,
'ti_rptr' is used as read index, where read occurs.
'ti_wptr' is a write index, where write would occur.
'ti_size' indicates total bytes to be read from the buffer.
While reading/writing to this buffer, index could exceed its
size. Add check to avoid OOB r/w access.
Reported-by: Huawei PSIRT <address@hidden>
Reported-by: Li Qiang <address@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/scsi/esp.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 591c817..3adb685 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -400,19 +400,17 @@ uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
trace_esp_mem_readb(saddr, s->rregs[saddr]);
switch (saddr) {
case ESP_FIFO:
- if (s->ti_size > 0) {
+ if ((s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
+ /* Data out. */
+ qemu_log_mask(LOG_UNIMP, "esp: PIO data read not implemented\n");
+ s->rregs[ESP_FIFO] = 0;
+ esp_raise_irq(s);
+ } else if (s->ti_rptr < s->ti_wptr) {
s->ti_size--;
- if ((s->rregs[ESP_RSTAT] & STAT_PIO_MASK) == 0) {
- /* Data out. */
- qemu_log_mask(LOG_UNIMP,
- "esp: PIO data read not implemented\n");
- s->rregs[ESP_FIFO] = 0;
- } else {
- s->rregs[ESP_FIFO] = s->ti_buf[s->ti_rptr++];
- }
+ s->rregs[ESP_FIFO] = s->ti_buf[s->ti_rptr++];
esp_raise_irq(s);
}
- if (s->ti_size == 0) {
+ if (s->ti_rptr == s->ti_wptr) {
s->ti_rptr = 0;
s->ti_wptr = 0;
}
@@ -456,7 +454,7 @@ 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] [PULL 00/11] Misc changes for 2016-06-06, Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 02/11] pc: allow raising low memory via max-ram-below-4g option, Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 03/11] hw/char: QOM'ify escc.c (fix), Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 05/11] scsi: mark TYPE_SCSI_DISK_BASE as abstract, Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 04/11] scsi: esp: check TI buffer index before read/write,
Paolo Bonzini <=
- [Qemu-devel] [PULL 01/11] tests: Rename tests/Makefile to tests/Makefile.include, Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 09/11] vnc: list the 'to' parameter of '-vnc' in the qemu man page, Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 10/11] Make avx2 configure test work with -O2, Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 07/11] Makefile: Derive "PKGVERSION" from "git describe" by default, Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 06/11] Makefile: Add a "FORCE" target, Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 11/11] avx2 configure: Use primitives in test, Paolo Bonzini, 2016/06/06
- [Qemu-devel] [PULL 08/11] scsi-disk: add missing break, Paolo Bonzini, 2016/06/06
- Re: [Qemu-devel] [PULL 00/11] Misc changes for 2016-06-06, Peter Maydell, 2016/06/06