From 73eaec81689662cf5c1cd6ac5de1152e19b0c14d Mon Sep 17 00:00:00 2001 From: Julius Werner Date: Fri, 3 May 2019 17:58:07 -0700 Subject: 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 Reviewed-on: https://review.coreboot.org/c/coreboot/+/32862 Reviewed-by: Hung-Te Lin Reviewed-by: Paul Menzel Tested-by: build bot (Jenkins) --- src/lib/device_tree.c | 18 ++++++++++++++++++ src/lib/fit.c | 8 +++----- 2 files changed, 21 insertions(+), 5 deletions(-) (limited to 'src/lib') 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; -- cgit v1.2.3