git: e94a1d6a7f2e - main - bhyve: improve bounds checks in hda_codec

The branch main has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=e94a1d6a7f2eb932850e1db418bf34d5c6991ce8

commit e94a1d6a7f2eb932850e1db418bf34d5c6991ce8
Author:     Pierre Pronchery <pierre@freebsdfoundation.org>
AuthorDate: 2024-07-24 14:56:54 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2024-10-03 21:14:11 +0000

    bhyve: improve bounds checks in hda_codec
    
    The function hda_codec_command is vulnerable to buffer over-read, the
    payload value is extracted from the command and used as an array index
    without any validation.
    Fortunately, the payload value is capped at 255, so the information
    disclosure is limited and only a small part of .rodata of bhyve binary
    can be disclosed.
    
    The risk is low because the leaked information is not sensitive. An
    attacker may be able to validate the version of the bhyve binary using
    this information disclosure (layout of .rodata information, ex:
    jmp_tables) before executing an exploit.
    
    Reported by:    Synacktiv
    Reviewed by:    christos, emaste
    Security:       HYP-13
    Sponsored by:   The Alpha-Omega Project
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D46098
---
 usr.sbin/bhyve/hda_codec.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/usr.sbin/bhyve/hda_codec.c b/usr.sbin/bhyve/hda_codec.c
index 1866149c020a..b7d6ec043675 100644
--- a/usr.sbin/bhyve/hda_codec.c
+++ b/usr.sbin/bhyve/hda_codec.c
@@ -521,7 +521,6 @@ hda_codec_command(struct hda_codec_inst *hci, uint32_t cmd_data)
 		payload = cmd_data & 0xffff;
 	}
 
-	assert(cad == hci->cad);
 	assert(hci);
 
 	hops = hci->hops;
@@ -530,7 +529,10 @@ hda_codec_command(struct hda_codec_inst *hci, uint32_t cmd_data)
 	sc = (struct hda_codec_softc *)hci->priv;
 	assert(sc);
 
-	assert(nid < sc->no_nodes);
+	if (cad != hci->cad || nid >= sc->no_nodes) {
+		DPRINTF("Invalid command data");
+		return (-1);
+	}
 
 	if (!hops->response) {
 		DPRINTF("The controller ops does not implement \
@@ -540,7 +542,8 @@ hda_codec_command(struct hda_codec_inst *hci, uint32_t cmd_data)
 
 	switch (verb) {
 	case HDA_CMD_VERB_GET_PARAMETER:
-		res = sc->get_parameters[nid][payload];
+		if (payload < HDA_CODEC_PARAMS_COUNT)
+			res = sc->get_parameters[nid][payload];
 		break;
 	case HDA_CMD_VERB_GET_CONN_LIST_ENTRY:
 		res = sc->conn_list[nid][0];