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@@ -0,0 +1,143 @@
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+From 72239fc85f3eda078547956608c063ab965e90e9 Mon Sep 17 00:00:00 2001
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+From: Teddy Reed <teddy.reed@gmail.com>
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+Date: Sat, 9 Jun 2018 11:38:05 -0400
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+Subject: [PATCH] vboot: Add FIT_SIGNATURE_MAX_SIZE protection
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+
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+This adds a new config value FIT_SIGNATURE_MAX_SIZE, which controls the
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+max size of a FIT header's totalsize field. The field is checked before
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+signature checks are applied to protect from reading past the intended
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+FIT regions.
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+
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+This field is not part of the vboot signature so it should be sanity
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+checked. If the field is corrupted then the structure or string region
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+reads may have unintended behavior, such as reading from device memory.
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+A default value of 256MB is set and intended to support most max storage
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+sizes.
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+
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+Suggested-by: Simon Glass <sjg@chromium.org>
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+Signed-off-by: Teddy Reed <teddy.reed@gmail.com>
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+Reviewed-by: Simon Glass <sjg@chromium.org>
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+
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+Upstream-Status: Backport[http://git.denx.de/?p=u-boot.git;a=commit;
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+ h=72239fc85f3eda078547956608c063ab965e90e9]
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+
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+CVE: CVE-2018-1000205
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+
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+Signed-off-by: Changqing Li <changqing.li@windriver.com>
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+---
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+ Kconfig | 10 ++++++++++
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+ common/image-sig.c | 5 +++++
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+ test/py/tests/test_vboot.py | 33 +++++++++++++++++++++++++++++++++
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+ tools/Makefile | 1 +
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+ 4 files changed, 49 insertions(+)
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+
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+diff --git a/Kconfig b/Kconfig
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+index 5a82c95..c8b86cd 100644
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+--- a/Kconfig
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++++ b/Kconfig
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+@@ -267,6 +267,16 @@ config FIT_SIGNATURE
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+ format support in this case, enable it using
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+ CONFIG_IMAGE_FORMAT_LEGACY.
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+
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++config FIT_SIGNATURE_MAX_SIZE
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++ hex "Max size of signed FIT structures"
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++ depends on FIT_SIGNATURE
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++ default 0x10000000
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++ help
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++ This option sets a max size in bytes for verified FIT uImages.
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++ A sane value of 256MB protects corrupted DTB structures from overlapping
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++ device memory. Assure this size does not extend past expected storage
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++ space.
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++
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+ config FIT_VERBOSE
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+ bool "Show verbose messages when FIT images fail"
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+ help
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+diff --git a/common/image-sig.c b/common/image-sig.c
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+index f65d883..8d2fd10 100644
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+--- a/common/image-sig.c
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++++ b/common/image-sig.c
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+@@ -156,6 +156,11 @@ static int fit_image_setup_verify(struct image_sign_info *info,
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+ {
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+ char *algo_name;
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+
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++ if (fdt_totalsize(fit) > CONFIG_FIT_SIGNATURE_MAX_SIZE) {
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++ *err_msgp = "Total size too large";
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++ return 1;
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++ }
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++
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+ if (fit_image_hash_get_algo(fit, noffset, &algo_name)) {
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+ *err_msgp = "Can't get hash algo property";
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+ return -1;
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+diff --git a/test/py/tests/test_vboot.py b/test/py/tests/test_vboot.py
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+index ee939f2..3d25ec3 100644
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+--- a/test/py/tests/test_vboot.py
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++++ b/test/py/tests/test_vboot.py
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+@@ -26,6 +26,7 @@ Tests run with both SHA1 and SHA256 hashing.
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+
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+ import pytest
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+ import sys
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++import struct
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+ import u_boot_utils as util
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+
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+ @pytest.mark.boardspec('sandbox')
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+@@ -105,6 +106,26 @@ def test_vboot(u_boot_console):
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+ util.run_and_log(cons, [mkimage, '-F', '-k', tmpdir, '-K', dtb,
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+ '-r', fit])
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+
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++ def replace_fit_totalsize(size):
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++ """Replace FIT header's totalsize with something greater.
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++
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++ The totalsize must be less than or equal to FIT_SIGNATURE_MAX_SIZE.
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++ If the size is greater, the signature verification should return false.
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++
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++ Args:
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++ size: The new totalsize of the header
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++
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++ Returns:
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++ prev_size: The previous totalsize read from the header
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++ """
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++ total_size = 0
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++ with open(fit, 'r+b') as handle:
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++ handle.seek(4)
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++ total_size = handle.read(4)
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++ handle.seek(4)
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++ handle.write(struct.pack(">I", size))
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++ return struct.unpack(">I", total_size)[0]
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++
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+ def test_with_algo(sha_algo):
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+ """Test verified boot with the given hash algorithm.
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+
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+@@ -146,6 +167,18 @@ def test_vboot(u_boot_console):
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+ util.run_and_log(cons, [fit_check_sign, '-f', fit, '-k', tmpdir,
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+ '-k', dtb])
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+
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++ # Replace header bytes
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++ bcfg = u_boot_console.config.buildconfig
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++ max_size = int(bcfg.get('config_fit_signature_max_size', 0x10000000), 0)
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++ existing_size = replace_fit_totalsize(max_size + 1)
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++ run_bootm(sha_algo, 'Signed config with bad hash', 'Bad Data Hash', False)
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++ cons.log.action('%s: Check overflowed FIT header totalsize' % sha_algo)
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++
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++ # Replace with existing header bytes
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++ replace_fit_totalsize(existing_size)
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++ run_bootm(sha_algo, 'signed config', 'dev+', True)
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++ cons.log.action('%s: Check default FIT header totalsize' % sha_algo)
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++
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+ # Increment the first byte of the signature, which should cause failure
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+ sig = util.run_and_log(cons, 'fdtget -t bx %s %s value' %
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+ (fit, sig_node))
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+diff --git a/tools/Makefile b/tools/Makefile
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+index 5dd33ed..0c3341e 100644
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+--- a/tools/Makefile
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++++ b/tools/Makefile
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+@@ -133,6 +133,7 @@ ifdef CONFIG_FIT_SIGNATURE
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+ # This affects include/image.h, but including the board config file
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+ # is tricky, so manually define this options here.
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+ HOST_EXTRACFLAGS += -DCONFIG_FIT_SIGNATURE
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++HOST_EXTRACFLAGS += -DCONFIG_FIT_SIGNATURE_MAX_SIZE=$(CONFIG_FIT_SIGNATURE_MAX_SIZE)
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+ endif
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+
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+ ifdef CONFIG_SYS_U_BOOT_OFFS
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+--
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+2.7.4
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+
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Changqing Li