On Tue, Oct 11, 2022 at 11:26:11AM -0700, Tadeusz Struk wrote:
> Add a new test get_next_tag_invalid_prop_len, which covers
> fdt_next_tag(), when it is passed an corrupted blob, with
> invalid property len values. The test runs twice, on a blob
> in sw and finished state.
>
> Signed-off-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxxx>
Merged, thanks.
> ---
> v6:
> * Remove RET_FAIL and call FAIL directly.
> * Fix typos
> v5:
> * Add back fdt_finish_reservemap() instead of directly calling
> fdt_set_off_dt_strings()
> * Call the test twice, on the blob in sw, and finished state
> * Use the new fdt_get_property_by_offset_w() helper to get the
> pointer to the property at a given address.
> v4:
> * I didn't keep track of the changes in the test code,
> but this version should have all the comments addressed.
> ---
> tests/.gitignore | 1 +
> tests/Makefile.tests | 2 +-
> tests/get_next_tag_invalid_prop_len.c | 100 ++++++++++++++++++++++++++
> tests/meson.build | 1 +
> tests/run_tests.sh | 1 +
> 5 files changed, 104 insertions(+), 1 deletion(-)
> create mode 100644 tests/get_next_tag_invalid_prop_len.c
>
> diff --git a/tests/.gitignore b/tests/.gitignore
> index 03bdde2..3376ed9 100644
> --- a/tests/.gitignore
> +++ b/tests/.gitignore
> @@ -74,3 +74,4 @@ tmp.*
> /truncated_memrsv
> /utilfdt_test
> /value-labels
> +/get_next_tag_invalid_prop_len
> diff --git a/tests/Makefile.tests b/tests/Makefile.tests
> index 2d36c5d..2c5b4c9 100644
> --- a/tests/Makefile.tests
> +++ b/tests/Makefile.tests
> @@ -4,7 +4,7 @@ LIB_TESTS_L = get_mem_rsv \
> get_path supernode_atdepth_offset parent_offset \
> node_offset_by_prop_value node_offset_by_phandle \
> node_check_compatible node_offset_by_compatible \
> - get_alias \
> + get_alias get_next_tag_invalid_prop_len \
> char_literal \
> sized_cells \
> notfound \
> diff --git a/tests/get_next_tag_invalid_prop_len.c b/tests/get_next_tag_invalid_prop_len.c
> new file mode 100644
> index 0000000..25d57c3
> --- /dev/null
> +++ b/tests/get_next_tag_invalid_prop_len.c
> @@ -0,0 +1,100 @@
> +// SPDX-License-Identifier: LGPL-2.1-or-later
> +/*
> + * libfdt - Flat Device Tree manipulation
> + * Testcase for fdt_next_tag()
> + */
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <stdint.h>
> +
> +#include <libfdt.h>
> +#include "tests.h"
> +#include "testdata.h"
> +
> +#define FDT_SIZE 65536
> +#define CHECK_ERR(err) \
> +({ if (err) \
> + FAIL("%s: %d: %s", __FILE__, __LINE__, fdt_strerror(err)); \
> +})
> +
> +static void fdt_next_tag_test(bool fdt_finished)
> +{
> + struct fdt_property *prp;
> + void *fdt;
> + int nextoff = 0, offset, err;
> + uint32_t tag;
> +
> + fdt = malloc(FDT_SIZE);
> + if (!fdt)
> + FAIL("Can't allocate memory");
> + err = fdt_create(fdt, FDT_SIZE);
> + CHECK_ERR(err);
> + err = fdt_finish_reservemap(fdt);
> + CHECK_ERR(err);
> + /* Create a root node and add two properties */
> + err = fdt_begin_node(fdt, "");
> + CHECK_ERR(err);
> + err = fdt_property_u32(fdt, "prop-int-32", 0x1234);
> + CHECK_ERR(err);
> + err = fdt_property_u32(fdt, "prop2-int-32", 0x4321);
> + CHECK_ERR(err);
> + err = fdt_end_node(fdt);
> + CHECK_ERR(err);
> + if (fdt_finished) {
> + /* Call fdt_finish to set the correct fdt state. */
> + err = fdt_finish(fdt);
> + CHECK_ERR(err);
> + }
> +
> + offset = fdt_first_property_offset(fdt, 0);
> + if (offset <= 0)
> + FAIL("Invalid offset %x, expected value greater than 0, finished=%d\n",
> + offset, fdt_finished);
> +
> + /* Normal case */
> + tag = fdt_next_tag(fdt, offset, &nextoff);
> + if (tag != FDT_PROP)
> + FAIL("Invalid tag %x, expected FDT_PROP, finished=%d\n",
> + tag, fdt_finished);
> + if (nextoff <= 0)
> + FAIL("Invalid nextoff %d, expected value greater than 0, finished=%d",
> + nextoff, fdt_finished);
> +
> + /* Get a writable ptr to the first property and corrupt the length */
> + prp = fdt_get_property_by_offset_w(fdt, offset, NULL);
> + if (!prp)
> + FAIL("Bad property pointer, finished=%d", fdt_finished);
> +
> + /* int overflow case */
> + prp->len = cpu_to_fdt32(0xFFFFFFFA);
> + tag = fdt_next_tag(fdt, offset, &nextoff);
> + if (tag != FDT_END)
> + FAIL("Invalid tag %x, expected premature FDT_END, finished=%d",
> + tag, fdt_finished);
> + if (nextoff != -FDT_ERR_BADSTRUCTURE)
> + FAIL("Invalid nextoff, expected error -FDT_ERR_BADSTRUCTURE, finished=%d",
> + fdt_finished);
> +
> + /* negative offset case */
> + prp->len = cpu_to_fdt32(0x7FFFFFFA);
> + tag = fdt_next_tag(fdt, offset, &nextoff);
> + if (tag != FDT_END)
> + FAIL("Invalid tag %x, expected premature FDT_END, finished=%d",
> + tag, fdt_finished);
> + if (nextoff != -FDT_ERR_BADSTRUCTURE)
> + FAIL("Invalid nextoff, expected -FDT_ERR_BADSTRUCTURE, finished=%d",
> + fdt_finished);
> +
> + free(fdt);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + test_init(argc, argv);
> +
> + fdt_next_tag_test(false);
> + fdt_next_tag_test(true);
> +
> + PASS();
> +}
> diff --git a/tests/meson.build b/tests/meson.build
> index 4ac154a..29a42dd 100644
> --- a/tests/meson.build
> +++ b/tests/meson.build
> @@ -47,6 +47,7 @@ tests = [
> 'get_path',
> 'get_phandle',
> 'get_prop_offset',
> + 'get_next_tag_invalid_prop_len',
> 'getprop',
> 'incbin',
> 'integer-expressions',
> diff --git a/tests/run_tests.sh b/tests/run_tests.sh
> index 244df8a..46678cb 100755
> --- a/tests/run_tests.sh
> +++ b/tests/run_tests.sh
> @@ -513,6 +513,7 @@ libfdt_tests () {
> run_dtc_test -I fs -O dts -o fs.test_tree1.test.dts $FSBASE/test_tree1
> run_dtc_test -I fs -O dtb -o fs.test_tree1.test.dtb $FSBASE/test_tree1
> run_test dtbs_equal_unordered -m fs.test_tree1.test.dtb test_tree1.dtb
> + run_test get_next_tag_invalid_prop_len
>
> ## https://github.com/dgibson/dtc/issues/64
> check_tests "$SRCDIR/phandle-args-overflow.dts" clocks_property
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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