diff options
Diffstat (limited to 'meta/recipes-bsp/u-boot/files/CVE-2018-1000205-2.patch')
| -rw-r--r-- | meta/recipes-bsp/u-boot/files/CVE-2018-1000205-2.patch | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/meta/recipes-bsp/u-boot/files/CVE-2018-1000205-2.patch b/meta/recipes-bsp/u-boot/files/CVE-2018-1000205-2.patch new file mode 100644 index 0000000000..bb79af1c7b --- /dev/null +++ b/meta/recipes-bsp/u-boot/files/CVE-2018-1000205-2.patch @@ -0,0 +1,143 @@ +From 72239fc85f3eda078547956608c063ab965e90e9 Mon Sep 17 00:00:00 2001 +From: Teddy Reed <teddy.reed@gmail.com> +Date: Sat, 9 Jun 2018 11:38:05 -0400 +Subject: [PATCH] vboot: Add FIT_SIGNATURE_MAX_SIZE protection + +This adds a new config value FIT_SIGNATURE_MAX_SIZE, which controls the +max size of a FIT header's totalsize field. The field is checked before +signature checks are applied to protect from reading past the intended +FIT regions. + +This field is not part of the vboot signature so it should be sanity +checked. If the field is corrupted then the structure or string region +reads may have unintended behavior, such as reading from device memory. +A default value of 256MB is set and intended to support most max storage +sizes. + +Suggested-by: Simon Glass <sjg@chromium.org> +Signed-off-by: Teddy Reed <teddy.reed@gmail.com> +Reviewed-by: Simon Glass <sjg@chromium.org> + +Upstream-Status: Backport[http://git.denx.de/?p=u-boot.git;a=commit; + h=72239fc85f3eda078547956608c063ab965e90e9] + +CVE: CVE-2018-1000205 + +Signed-off-by: Changqing Li <changqing.li@windriver.com> +--- + Kconfig | 10 ++++++++++ + common/image-sig.c | 5 +++++ + test/py/tests/test_vboot.py | 33 +++++++++++++++++++++++++++++++++ + tools/Makefile | 1 + + 4 files changed, 49 insertions(+) + +diff --git a/Kconfig b/Kconfig +index 5a82c95..c8b86cd 100644 +--- a/Kconfig ++++ b/Kconfig +@@ -267,6 +267,16 @@ config FIT_SIGNATURE + format support in this case, enable it using + CONFIG_IMAGE_FORMAT_LEGACY. + ++config FIT_SIGNATURE_MAX_SIZE ++ hex "Max size of signed FIT structures" ++ depends on FIT_SIGNATURE ++ default 0x10000000 ++ help ++ This option sets a max size in bytes for verified FIT uImages. ++ A sane value of 256MB protects corrupted DTB structures from overlapping ++ device memory. Assure this size does not extend past expected storage ++ space. ++ + config FIT_VERBOSE + bool "Show verbose messages when FIT images fail" + help +diff --git a/common/image-sig.c b/common/image-sig.c +index f65d883..8d2fd10 100644 +--- a/common/image-sig.c ++++ b/common/image-sig.c +@@ -156,6 +156,11 @@ static int fit_image_setup_verify(struct image_sign_info *info, + { + char *algo_name; + ++ if (fdt_totalsize(fit) > CONFIG_FIT_SIGNATURE_MAX_SIZE) { ++ *err_msgp = "Total size too large"; ++ return 1; ++ } ++ + if (fit_image_hash_get_algo(fit, noffset, &algo_name)) { + *err_msgp = "Can't get hash algo property"; + return -1; +diff --git a/test/py/tests/test_vboot.py b/test/py/tests/test_vboot.py +index ee939f2..3d25ec3 100644 +--- a/test/py/tests/test_vboot.py ++++ b/test/py/tests/test_vboot.py +@@ -26,6 +26,7 @@ Tests run with both SHA1 and SHA256 hashing. + + import pytest + import sys ++import struct + import u_boot_utils as util + + @pytest.mark.boardspec('sandbox') +@@ -105,6 +106,26 @@ def test_vboot(u_boot_console): + util.run_and_log(cons, [mkimage, '-F', '-k', tmpdir, '-K', dtb, + '-r', fit]) + ++ def replace_fit_totalsize(size): ++ """Replace FIT header's totalsize with something greater. ++ ++ The totalsize must be less than or equal to FIT_SIGNATURE_MAX_SIZE. ++ If the size is greater, the signature verification should return false. ++ ++ Args: ++ size: The new totalsize of the header ++ ++ Returns: ++ prev_size: The previous totalsize read from the header ++ """ ++ total_size = 0 ++ with open(fit, 'r+b') as handle: ++ handle.seek(4) ++ total_size = handle.read(4) ++ handle.seek(4) ++ handle.write(struct.pack(">I", size)) ++ return struct.unpack(">I", total_size)[0] ++ + def test_with_algo(sha_algo): + """Test verified boot with the given hash algorithm. + +@@ -146,6 +167,18 @@ def test_vboot(u_boot_console): + util.run_and_log(cons, [fit_check_sign, '-f', fit, '-k', tmpdir, + '-k', dtb]) + ++ # Replace header bytes ++ bcfg = u_boot_console.config.buildconfig ++ max_size = int(bcfg.get('config_fit_signature_max_size', 0x10000000), 0) ++ existing_size = replace_fit_totalsize(max_size + 1) ++ run_bootm(sha_algo, 'Signed config with bad hash', 'Bad Data Hash', False) ++ cons.log.action('%s: Check overflowed FIT header totalsize' % sha_algo) ++ ++ # Replace with existing header bytes ++ replace_fit_totalsize(existing_size) ++ run_bootm(sha_algo, 'signed config', 'dev+', True) ++ cons.log.action('%s: Check default FIT header totalsize' % sha_algo) ++ + # Increment the first byte of the signature, which should cause failure + sig = util.run_and_log(cons, 'fdtget -t bx %s %s value' % + (fit, sig_node)) +diff --git a/tools/Makefile b/tools/Makefile +index 5dd33ed..0c3341e 100644 +--- a/tools/Makefile ++++ b/tools/Makefile +@@ -133,6 +133,7 @@ ifdef CONFIG_FIT_SIGNATURE + # This affects include/image.h, but including the board config file + # is tricky, so manually define this options here. + HOST_EXTRACFLAGS += -DCONFIG_FIT_SIGNATURE ++HOST_EXTRACFLAGS += -DCONFIG_FIT_SIGNATURE_MAX_SIZE=$(CONFIG_FIT_SIGNATURE_MAX_SIZE) + endif + + ifdef CONFIG_SYS_U_BOOT_OFFS +-- +2.7.4 + |