The branch main has been updated by jhb:
URL:
https://cgit.FreeBSD.org/src/commit/?id=bb31aee26bd13307d97c5d5bf2b10bf05bdc18fd
commit bb31aee26bd13307d97c5d5bf2b10bf05bdc18fd
Author: John Baldwin <j...@freebsd.org>
AuthorDate: 2022-08-29 22:36:11 +0000
Commit: John Baldwin <j...@freebsd.org>
CommitDate: 2022-08-29 22:37:27 +0000
bhyve virtio-scsi: Avoid out of bounds accesses to guest requests.
- Ignore I/O requests with insufficiently sized input or output
buffers (those not containing compete request headers).
- Ignore control requests with improperly sized buffers.
- While here, explicitly zero the output header of an I/O request to
avoid leaking malloc garbage from the host if the header is not
fully populated.
PR: 264521
Reported by: Robert Morris <r...@lcs.mit.edu>
Reviewed by: mav, emaste
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D36271
---
usr.sbin/bhyve/pci_virtio_scsi.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/usr.sbin/bhyve/pci_virtio_scsi.c b/usr.sbin/bhyve/pci_virtio_scsi.c
index 6d867e7e3b56..b50b6e9fd047 100644
--- a/usr.sbin/bhyve/pci_virtio_scsi.c
+++ b/usr.sbin/bhyve/pci_virtio_scsi.c
@@ -364,14 +364,27 @@ pci_vtscsi_control_handle(struct pci_vtscsi_softc *sc,
void *buf,
struct pci_vtscsi_ctrl_an *an;
uint32_t type;
+ if (bufsize < sizeof(uint32_t)) {
+ WPRINTF("ignoring truncated control request");
+ return (0);
+ }
+
type = *(uint32_t *)buf;
if (type == VIRTIO_SCSI_T_TMF) {
+ if (bufsize != sizeof(*tmf)) {
+ WPRINTF("ignoring tmf request with size %zu", bufsize);
+ return (0);
+ }
tmf = (struct pci_vtscsi_ctrl_tmf *)buf;
return (pci_vtscsi_tmf_handle(sc, tmf));
}
if (type == VIRTIO_SCSI_T_AN_QUERY) {
+ if (bufsize != sizeof(*an)) {
+ WPRINTF("ignoring AN request with size %zu", bufsize);
+ return (0);
+ }
an = (struct pci_vtscsi_ctrl_an *)buf;
return (pci_vtscsi_an_handle(sc, an));
}
@@ -468,6 +481,15 @@ pci_vtscsi_request_handle(struct pci_vtscsi_queue *q,
struct iovec *iov_in,
uint32_t ext_data_len = 0, ext_sg_entries = 0;
int err, nxferred;
+ if (count_iov(iov_out, niov_out) < VTSCSI_OUT_HEADER_LEN(sc)) {
+ WPRINTF("ignoring request with insufficient output");
+ return (0);
+ }
+ if (count_iov(iov_in, niov_in) < VTSCSI_IN_HEADER_LEN(sc)) {
+ WPRINTF("ignoring request with incomplete header");
+ return (0);
+ }
+
seek_iov(iov_in, niov_in, data_iov_in, &data_niov_in,
VTSCSI_IN_HEADER_LEN(sc));
seek_iov(iov_out, niov_out, data_iov_out, &data_niov_out,
@@ -477,7 +499,7 @@ pci_vtscsi_request_handle(struct pci_vtscsi_queue *q,
struct iovec *iov_in,
truncate_iov(iov_out, &niov_out, VTSCSI_OUT_HEADER_LEN(sc));
iov_to_buf(iov_in, niov_in, (void **)&cmd_rd);
- cmd_wr = malloc(VTSCSI_OUT_HEADER_LEN(sc));
+ cmd_wr = calloc(1, VTSCSI_OUT_HEADER_LEN(sc));
io = ctl_scsi_alloc_io(sc->vss_iid);
ctl_scsi_zero_io(io);
