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authorLeah Rowe <leah@libreboot.org>2025-05-08 20:27:42 +0100
committerLeah Rowe <leah@libreboot.org>2025-05-08 20:46:05 +0100
commit021e7615c84ddf91edcd13a6385fe1bd6ca51ebb (patch)
tree789a89275c65958fdd60a7f4ac36a9095fc4625e /config/submodule/coreboot/coreboot413/vboot
parentfe926052441151722886edb5693a961342b3aa9e (diff)
HP 820 G2: Use fam15h cbfstool tree for refcode
We used cbfstool from coreboot 4.13, because it was the last version to work with the particular format used for stage files, before the CBFS standard changed in newer releases of cbfstool. When I added this board to Libreboot, it was source-only at first so it didn't matter. I didn't want to do a standalone cbfstool binary, in case some people decided to use that one on newer boards, which would cause all sorts of issues. So I bodged it and just included an import of coreboot 4.13. Well, the cbfstool from coreboot 4.11, as used for FAM15H AMD boards, is compatible. I checked the code diff between the two, and there is no meaningful difference. I've tested this, and it works, since the last release or two now includes 820 G2 images, so I was able to use those with ./mk inject, to verify whether the refcode file is still grabbed properly. We need the refcode to handle MRC on Broadwell platform, but we extract it from an old Google Chromebook image, that uses the old CBFS stage file layout. This change solves my problem: the problem was that releases are bloated further, due to including this extra coreboot version. This should reduce the size of the next release considerably, especially after decompressing the tarball. Signed-off-by: Leah Rowe <leah@libreboot.org>
Diffstat (limited to 'config/submodule/coreboot/coreboot413/vboot')
-rw-r--r--config/submodule/coreboot/coreboot413/vboot/module.cfg5
-rw-r--r--config/submodule/coreboot/coreboot413/vboot/patches/0001-extract_vmlinuz.c-Fix-the-bounds-check-on-vmlinuz_he.patch178
2 files changed, 0 insertions, 183 deletions
diff --git a/config/submodule/coreboot/coreboot413/vboot/module.cfg b/config/submodule/coreboot/coreboot413/vboot/module.cfg
deleted file mode 100644
index 79c98870..00000000
--- a/config/submodule/coreboot/coreboot413/vboot/module.cfg
+++ /dev/null
@@ -1,5 +0,0 @@
-# SPDX-License-Identifier: GPL-3.0-or-later
-
-subrepo="https://review.coreboot.org/vboot.git"
-subrepo_bkup="https://github.com/coreboot/vboot"
-subhash="4c523ed10f25de872ac0513ebd6ca53d3970b9de"
diff --git a/config/submodule/coreboot/coreboot413/vboot/patches/0001-extract_vmlinuz.c-Fix-the-bounds-check-on-vmlinuz_he.patch b/config/submodule/coreboot/coreboot413/vboot/patches/0001-extract_vmlinuz.c-Fix-the-bounds-check-on-vmlinuz_he.patch
deleted file mode 100644
index 1ac41de6..00000000
--- a/config/submodule/coreboot/coreboot413/vboot/patches/0001-extract_vmlinuz.c-Fix-the-bounds-check-on-vmlinuz_he.patch
+++ /dev/null
@@ -1,178 +0,0 @@
-From 195f61375aeec9eec16604ec59f6eda2e6058cc1 Mon Sep 17 00:00:00 2001
-From: "Luke T. Shumaker" <lukeshu@lukeshu.com>
-Date: Thu, 30 May 2024 14:08:33 -0600
-Subject: [PATCH 1/1] extract_vmlinuz.c: Fix the bounds check on
- vmlinuz_header_{offset,size}
-
-The check on vmlinuz_header_offset and vmlinuz_header_size is obviously
-wrong:
-
- if (!vmlinuz_header_size ||
- kpart_data + vmlinuz_header_offset + vmlinuz_header_size >
- kpart_data) {
- return 1;
- }
-
-`kpart_data + some_unsigned_values` can obviously never be `> kpart_data`,
-unless something has overflowed! And `vmlinuz_header_offset` hasn't even
-been set yet (besides being initialized to zero)!
-
-GCC will deduce that if the check didn't cause the function to bail, then
-vmlinuz_header_size (a uint32_t) must be "negative"; that is: in the range
-[2GiB,4GiB).
-
-On platforms where size_t is 32-bits, this is *especially* broken.
-memcpy's size argument must be in the range [0,2GiB). Because GCC has
-proved that vmlinuz_header_size is higher than that, it will fail to
-compile:
-
- host/lib/extract_vmlinuz.c:67:9: error: 'memcpy' specified bound between 2147483648 and 4294967295 exceeds maximum object size 2147483647 [-Werror=stringop-overflow=]
-
-So, fix the check.
-
-I can now say that what I suspect the original author meant to write would
-be the following patch, if `vmlinuz_header_offset` were already set:
-
- -kpart_data + vmlinuz_header_offset + vmlinuz_header_size > kpart_data
- +now + vmlinuz_header_offset + vmlinuz_header_size > kpart_size
-
-This hypothesis is supported by `now` not getting incremented by
-`kblob_size` the way it is for the keyblock and preamble sizes.
-
-However, we can also see that even this "corrected" bounds check is
-insufficient: it does not detect the vmlinuz_header overflowing into
-kblob_data.
-
-OK, so let's describe the fix:
-
-Have a `*vmlinuz_header` pointer instead of a
-`uint64_t vmlinuz_header_offset`, to be more similar to all the other
-regions. With this change, the correct check becomes a simple
-
- vmlinuz_header + vmlinuz_header_size > kblob_data
-
-While we're at it, make some changes that could have helped avoid this in
-the first place:
-
- - Add comments.
- - Calculate the vmlinuz_header offset right away, instead of waiting.
- - Go ahead and increment `now` by `kblob_size`, to increase regularity.
-
-Change-Id: I5c03e49070b6dd2e04459566ef7dd129d27736e4
----
- host/lib/extract_vmlinuz.c | 72 +++++++++++++++++++++++++++-----------
- 1 file changed, 51 insertions(+), 21 deletions(-)
-
-diff --git a/host/lib/extract_vmlinuz.c b/host/lib/extract_vmlinuz.c
-index 4ccfcf33..d2c09443 100644
---- a/host/lib/extract_vmlinuz.c
-+++ b/host/lib/extract_vmlinuz.c
-@@ -15,16 +15,44 @@
-
- int ExtractVmlinuz(void *kpart_data, size_t kpart_size,
- void **vmlinuz_out, size_t *vmlinuz_size) {
-+ // We're going to be extracting `vmlinuz_header` and
-+ // `kblob_data`, and returning the concatenation of them.
-+ //
-+ // kpart_data = +-[kpart_size]------------------------------------+
-+ // | |
-+ // keyblock = | +-[keyblock->keyblock_size]-------------------+ |
-+ // | | struct vb2_keyblock keyblock | |
-+ // | | char [] ...data... | |
-+ // | +---------------------------------------------+ |
-+ // | |
-+ // preamble = | +-[preamble->preamble_size]-------------------+ |
-+ // | | struct vb2_kernel_preamble preamble | |
-+ // | | char [] ...data... | |
-+ // | | char [] vmlinuz_header | |
-+ // | | char [] ...data... | |
-+ // | +---------------------------------------------+ |
-+ // | |
-+ // kblob_data= | +-[preamble->body_signature.data_size]--------+ |
-+ // | | char [] ...data... | |
-+ // | +---------------------------------------------+ |
-+ // | |
-+ // +-------------------------------------------------+
-+
- size_t now = 0;
-+ // The 3 sections of kpart_data.
-+ struct vb2_keyblock *keyblock = NULL;
- struct vb2_kernel_preamble *preamble = NULL;
- uint8_t *kblob_data = NULL;
- uint32_t kblob_size = 0;
-+ // vmlinuz_header
-+ uint8_t *vmlinuz_header = NULL;
- uint32_t vmlinuz_header_size = 0;
-- uint64_t vmlinuz_header_address = 0;
-- uint64_t vmlinuz_header_offset = 0;
-+ // The concatenated result.
- void *vmlinuz = NULL;
-
-- struct vb2_keyblock *keyblock = (struct vb2_keyblock *)kpart_data;
-+ // Isolate the 3 sections of kpart_data.
-+
-+ keyblock = (struct vb2_keyblock *)kpart_data;
- now += keyblock->keyblock_size;
- if (now > kpart_size)
- return 1;
-@@ -36,37 +64,39 @@ int ExtractVmlinuz(void *kpart_data, size_t kpart_size,
-
- kblob_data = kpart_data + now;
- kblob_size = preamble->body_signature.data_size;
--
-- if (!kblob_data || (now + kblob_size) > kpart_size)
-+ now += kblob_size;
-+ if (now > kpart_size)
- return 1;
-
-+ // Find `vmlinuz_header` within `preamble`.
-+
- if (preamble->header_version_minor > 0) {
-- vmlinuz_header_address = preamble->vmlinuz_header_address;
-+ // calculate the vmlinuz_header offset from
-+ // the beginning of the kpart_data. The kblob doesn't
-+ // include the body_load_offset, but does include
-+ // the keyblock and preamble sections.
-+ size_t vmlinuz_header_offset =
-+ preamble->vmlinuz_header_address -
-+ preamble->body_load_address +
-+ keyblock->keyblock_size +
-+ preamble->preamble_size;
-+
-+ vmlinuz_header = kpart_data + vmlinuz_header_offset;
- vmlinuz_header_size = preamble->vmlinuz_header_size;
- }
-
-- if (!vmlinuz_header_size ||
-- kpart_data + vmlinuz_header_offset + vmlinuz_header_size >
-- kpart_data) {
-+ if (!vmlinuz_header ||
-+ !vmlinuz_header_size ||
-+ vmlinuz_header + vmlinuz_header_size > kblob_data) {
- return 1;
- }
-
-- // calculate the vmlinuz_header offset from
-- // the beginning of the kpart_data. The kblob doesn't
-- // include the body_load_offset, but does include
-- // the keyblock and preamble sections.
-- vmlinuz_header_offset = vmlinuz_header_address -
-- preamble->body_load_address +
-- keyblock->keyblock_size +
-- preamble->preamble_size;
-+ // Concatenate and return.
-
- vmlinuz = malloc(vmlinuz_header_size + kblob_size);
- if (vmlinuz == NULL)
- return 1;
--
-- memcpy(vmlinuz, kpart_data + vmlinuz_header_offset,
-- vmlinuz_header_size);
--
-+ memcpy(vmlinuz, vmlinuz_header, vmlinuz_header_size);
- memcpy(vmlinuz + vmlinuz_header_size, kblob_data, kblob_size);
-
- *vmlinuz_out = vmlinuz;
---
-2.45.1
-