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authorJulius Werner <jwerner@chromium.org>2019-05-03 17:58:07 -0700
committerPatrick Georgi <pgeorgi@google.com>2019-06-04 11:22:47 +0000
commit73eaec81689662cf5c1cd6ac5de1152e19b0c14d (patch)
treee58a86d7c98c6e673cf6f09babbc2af794bdaa62
parent9636a106d43453976addb39253cf70bc65ea1224 (diff)
device_tree: Add version checks
This patch adds a few more sanity checks to the FDT header parsing to make sure that our code can support the version that is passed in. This patch was adapted from depthcharge's http://crosreview.com/1536384 Change-Id: I06c112f540213c8db7c2455c2e8a4e8e4f337b78 Signed-off-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://review.coreboot.org/c/coreboot/+/32862 Reviewed-by: Hung-Te Lin <hungte@chromium.org> Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
-rw-r--r--src/include/device_tree.h3
-rw-r--r--src/lib/device_tree.c18
-rw-r--r--src/lib/fit.c8
3 files changed, 23 insertions, 6 deletions
diff --git a/src/include/device_tree.h b/src/include/device_tree.h
index 14be8322c6..96902b893b 100644
--- a/src/include/device_tree.h
+++ b/src/include/device_tree.h
@@ -33,7 +33,7 @@ struct fdt_header {
uint32_t reserve_map_offset;
uint32_t version;
- uint32_t last_compatible_version;
+ uint32_t last_comp_version;
uint32_t boot_cpuid_phys;
@@ -42,6 +42,7 @@ struct fdt_header {
};
#define FDT_HEADER_MAGIC 0xd00dfeed
+#define FDT_SUPPORTED_VERSION 17
#define FDT_TOKEN_BEGIN_NODE 1
#define FDT_TOKEN_END_NODE 2
#define FDT_TOKEN_PROPERTY 3
diff --git a/src/lib/device_tree.c b/src/lib/device_tree.c
index bb40eee231..7a3128efcf 100644
--- a/src/lib/device_tree.c
+++ b/src/lib/device_tree.c
@@ -220,6 +220,24 @@ struct device_tree *fdt_unflatten(const void *blob)
const struct fdt_header *header = (const struct fdt_header *)blob;
tree->header = header;
+ uint32_t magic = be32toh(header->magic);
+ uint32_t version = be32toh(header->version);
+ uint32_t last_comp_version = be32toh(header->last_comp_version);
+
+ if (magic != FDT_HEADER_MAGIC) {
+ printk(BIOS_DEBUG, "Invalid device tree magic %#.8x!\n", magic);
+ return NULL;
+ }
+ if (last_comp_version > FDT_SUPPORTED_VERSION) {
+ printk(BIOS_DEBUG, "Unsupported device tree version %u(>=%u)\n",
+ version, last_comp_version);
+ return NULL;
+ }
+ if (version > FDT_SUPPORTED_VERSION)
+ printk(BIOS_DEBUG,
+ "NOTE: FDT version %u too new, should add support!\n",
+ version);
+
uint32_t struct_offset = be32toh(header->structure_offset);
uint32_t strings_offset = be32toh(header->strings_offset);
uint32_t reserve_offset = be32toh(header->reserve_map_offset);
diff --git a/src/lib/fit.c b/src/lib/fit.c
index d15641db9a..c98ba2f802 100644
--- a/src/lib/fit.c
+++ b/src/lib/fit.c
@@ -423,19 +423,17 @@ static void fit_update_compat(const void *fdt_blob,
struct fit_config_node *fit_load(void *fit)
{
- struct fdt_header *header = (struct fdt_header *)fit;
struct fit_image_node *image;
struct fit_config_node *config;
struct compat_string_entry *compat_node;
printk(BIOS_DEBUG, "FIT: Loading FIT from %p\n", fit);
- if (be32toh(header->magic) != FDT_HEADER_MAGIC) {
- printk(BIOS_ERR, "FIT: Bad header magic value 0x%08x.\n",
- be32toh(header->magic));
+ struct device_tree *tree = fdt_unflatten(fit);
+ if (!tree) {
+ printk(BIOS_ERR, "ERROR: Failed to unflatten FIT image!\n");
return NULL;
}
- struct device_tree *tree = fdt_unflatten(fit);
const char *default_config_name = NULL;
struct fit_config_node *default_config = NULL;