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From:   Lubomir Rintel <lkundrak@v3.sk>
To:     Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc:     Peter Jones <pjones@redhat.com>, linux-kernel@vger.kernel.org,
        Lubomir Rintel <lkundrak@v3.sk>
Subject: [RESEND PATCH] iscsi_ibft: Don't limits Targets and NICs to two
Date:   Sat, 21 Dec 2019 08:09:56 +0100
Message-Id: <20191221070956.268321-1-lkundrak@v3.sk>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

According to iSCSI Boot Firmware Table Version 1.03 [1], the length of
the control table is ">=3D 18", where the optional expansion structure
pointer follow the mandatory ones. This allows for more than two NICs
and Targets.

[1] ftp://ftp.software.ibm.com/systems/support/bladecenter/iscsi_boot_fir=
mware_table_v1.03.pdf

Let's enforce the minimum length of the control structure instead
instead of limiting it to the smallest allowed size.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
---
 drivers/firmware/iscsi_ibft.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/iscsi_ibft.c b/drivers/firmware/iscsi_ibft.=
c
index 7e12cbdf957cc..96758b71a8db8 100644
--- a/drivers/firmware/iscsi_ibft.c
+++ b/drivers/firmware/iscsi_ibft.c
@@ -104,6 +104,7 @@ struct ibft_control {
 	u16 tgt0_off;
 	u16 nic1_off;
 	u16 tgt1_off;
+	u16 expansion[0];
 } __attribute__((__packed__));
=20
 struct ibft_initiator {
@@ -235,7 +236,7 @@ static int ibft_verify_hdr(char *t, struct ibft_hdr *=
hdr, int id, int length)
 				"found %d instead!\n", t, id, hdr->id);
 		return -ENODEV;
 	}
-	if (hdr->length !=3D length) {
+	if (length && hdr->length !=3D length) {
 		printk(KERN_ERR "iBFT error: We expected the %s " \
 				"field header.length to have %d but " \
 				"found %d instead!\n", t, length, hdr->length);
@@ -749,16 +750,16 @@ static int __init ibft_register_kobjects(struct acp=
i_table_ibft *header)
 	control =3D (void *)header + sizeof(*header);
 	end =3D (void *)control + control->hdr.length;
 	eot_offset =3D (void *)header + header->header.length - (void *)control=
;
-	rc =3D ibft_verify_hdr("control", (struct ibft_hdr *)control, id_contro=
l,
-			     sizeof(*control));
+	rc =3D ibft_verify_hdr("control", (struct ibft_hdr *)control, id_contro=
l, 0);
=20
 	/* iBFT table safety checking */
 	rc |=3D ((control->hdr.index) ? -ENODEV : 0);
+	rc |=3D ((control->hdr.length < sizeof(*control)) ? -ENODEV : 0);
 	if (rc) {
 		printk(KERN_ERR "iBFT error: Control header is invalid!\n");
 		return rc;
 	}
-	for (ptr =3D &control->initiator_off; ptr < end; ptr +=3D sizeof(u16)) =
{
+	for (ptr =3D &control->initiator_off; ptr + sizeof(u16) <=3D end; ptr +=
=3D sizeof(u16)) {
 		offset =3D *(u16 *)ptr;
 		if (offset && offset < header->header.length &&
 						offset < eot_offset) {
--=20
2.24.1