Using linux 6.x guest, at boot time, an inquiry on a scsi-generic
device makes qemu crash. This is caused by a buffer overflow when
scsi-generic patches the block limits VPD page.
Do the operations on a temporary on-stack buffer that is guaranteed
to be large enough.
Reported-by: Théo Maillart <tmaill...@freebox.fr>
Analyzed-by: Théo Maillart <tmaill...@freebox.fr>
Cc: qemu-sta...@nongnu.org
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
hw/scsi/scsi-generic.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
index ac9fa662b4e3..2417f0ad8479 100644
--- a/hw/scsi/scsi-generic.c
+++ b/hw/scsi/scsi-generic.c
@@ -191,12 +191,16 @@ static int scsi_handle_inquiry_reply(SCSIGenericReq *r,
SCSIDevice *s, int len)
if ((s->type == TYPE_DISK || s->type == TYPE_ZBC) &&
(r->req.cmd.buf[1] & 0x01)) {
page = r->req.cmd.buf[2];
- if (page == 0xb0) {
+ if (page == 0xb0 && r->buflen >= 8) {
+ uint8_t buf[16] = {};
+ uint8_t buf_used = MIN(r->buflen, 16);
uint64_t max_transfer = calculate_max_transfer(s);
- stl_be_p(&r->buf[8], max_transfer);
- /* Also take care of the opt xfer len. */
- stl_be_p(&r->buf[12],
- MIN_NON_ZERO(max_transfer, ldl_be_p(&r->buf[12])));
+
+ memcpy(buf, r->buf, buf_used);
+ stl_be_p(&buf[8], max_transfer);
+ stl_be_p(&buf[12], MIN_NON_ZERO(max_transfer, ldl_be_p(&buf[12])));
+ memcpy(r->buf + 8, buf + 8, buf_used - 8);
+
} else if (s->needs_vpd_bl_emulation && page == 0x00 && r->buflen >=
4) {
/*
* Now we're capable of supplying the VPD Block Limits
--
2.40.1
