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[Qemu-devel] [PATCH] SCSI Improved checking for LBA out of range
From: |
Ronnie Sahlberg |
Subject: |
[Qemu-devel] [PATCH] SCSI Improved checking for LBA out of range |
Date: |
Thu, 12 Jul 2012 17:05:12 +1000 |
Improve the tests for the LBA to cover more cases, the new test looks like this
if (r->req.cmd.lba > r->req.cmd.lba + len
|| r->req.cmd.lba + len > s->qdev.max_lba + 1) {
For the 16 byte opcodes, the lba is a uint64, so the first check is to make
sure that we do not wrap.
For example if an opcode would specify the LBA:0xffffffffffffffff and LEN:2
then lba+len would wrap to 1.
The second part of the test is to verify that ALL requested blocks are
available, not just the first one.
Signed-off-by: Ronnie Sahlberg <address@hidden>
---
hw/scsi-disk.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index b2f3c0c..2c2be33 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -1558,7 +1558,8 @@ static int32_t scsi_send_command(SCSIRequest *req,
uint8_t *buf)
if (r->req.cmd.buf[1] & 0xe0) {
goto fail;
}
- if (r->req.cmd.lba > s->qdev.max_lba) {
+ if (r->req.cmd.lba > r->req.cmd.lba + len
+ || r->req.cmd.lba + len > s->qdev.max_lba + 1) {
goto illegal_lba;
}
r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
@@ -1581,7 +1582,8 @@ static int32_t scsi_send_command(SCSIRequest *req,
uint8_t *buf)
if (r->req.cmd.buf[1] & 0xe0) {
goto fail;
}
- if (r->req.cmd.lba > s->qdev.max_lba) {
+ if (r->req.cmd.lba > r->req.cmd.lba + len
+ || r->req.cmd.lba + len > s->qdev.max_lba + 1) {
goto illegal_lba;
}
r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
--
1.7.3.1