From c5819701a3de61e2ba2ef7ad0b616565b32305e5 Mon Sep 17 00:00:00 2001
From: Simon Glass <sjg@chromium.org>
Date: Mon, 15 Feb 2021 17:08:09 -0700
Subject: [PATCH] image: Adjust the workings of fit_check_format()

At present this function does not accept a size for the FIT. This means
that it must be read from the FIT itself, introducing potential security
risk. Update the function to include a size parameter, which can be
invalid, in which case fit_check_format() calculates it.

For now no callers pass the size, but this can be updated later.

Also adjust the return value to an error code so that all the different
types of problems can be distinguished by the user.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Bruce Monroe <bruce.monroe@intel.com>
Reported-by: Arie Haenel <arie.haenel@intel.com>
Reported-by: Julien Lenoir <julien.lenoir@intel.com>

---
 arch/arm/cpu/armv8/sec_firmware.c  |  2 +-
 cmd/bootm.c                        |  6 ++--
 cmd/disk.c                         |  2 +-
 cmd/fpga.c                         |  2 +-
 cmd/nand.c                         |  2 +-
 cmd/source.c                       |  2 +-
 cmd/ximg.c                         |  2 +-
 common/image-fdt.c                 |  2 +-
 common/image-fit.c                 | 45 +++++++++++++++---------------
 common/splash_source.c             |  6 ++--
 common/update.c                    |  2 +-
 drivers/fpga/socfpga_arria10.c     |  6 ++--
 drivers/net/fsl-mc/mc.c            |  2 +-
 drivers/net/pfe_eth/pfe_firmware.c |  2 +-
 include/image.h                    | 21 +++++++++++++-
 tools/fit_common.c                 |  3 +-
 tools/fit_image.c                  |  2 +-
 tools/mkimage.h                    |  2 ++
 18 files changed, 67 insertions(+), 44 deletions(-)

diff --git a/arch/arm/cpu/armv8/sec_firmware.c b/arch/arm/cpu/armv8/sec_firmware.c
index bfc0fac3..0561f5ef 100644
--- a/arch/arm/cpu/armv8/sec_firmware.c
+++ b/arch/arm/cpu/armv8/sec_firmware.c
@@ -316,7 +316,7 @@ __weak bool sec_firmware_is_valid(const void *sec_firmware_img)
 		return false;
 	}
 
-	if (!fit_check_format(sec_firmware_img)) {
+	if (fit_check_format(sec_firmware_img, IMAGE_SIZE_INVAL)) {
 		printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
 		return false;
 	}
diff --git a/cmd/bootm.c b/cmd/bootm.c
index d5f877cb..cf9c8def 100644
--- a/cmd/bootm.c
+++ b/cmd/bootm.c
@@ -291,7 +291,7 @@ static int image_info(ulong addr)
 	case IMAGE_FORMAT_FIT:
 		puts("   FIT image found\n");
 
-		if (!fit_check_format(hdr)) {
+		if (fit_check_format(hdr, IMAGE_SIZE_INVAL)) {
 			puts("Bad FIT image format!\n");
 			unmap_sysmem(hdr);
 			return 1;
@@ -368,7 +368,7 @@ static int do_imls_nor(void)
 #endif
 #if defined(CONFIG_FIT)
 			case IMAGE_FORMAT_FIT:
-				if (!fit_check_format(hdr))
+				if (fit_check_format(hdr, IMAGE_SIZE_INVAL))
 					goto next_sector;
 
 				printf("FIT Image at %08lX:\n", (ulong)hdr);
@@ -448,7 +448,7 @@ static int nand_imls_fitimage(struct mtd_info *mtd, int nand_dev, loff_t off,
 		return ret;
 	}
 
-	if (!fit_check_format(imgdata)) {
+	if (fit_check_format(imgdata, IMAGE_SIZE_INVAL)) {
 		free(imgdata);
 		return 0;
 	}
diff --git a/cmd/disk.c b/cmd/disk.c
index 8060e753..3195db91 100644
--- a/cmd/disk.c
+++ b/cmd/disk.c
@@ -114,7 +114,7 @@ int common_diskboot(struct cmd_tbl *cmdtp, const char *intf, int argc,
 	/* This cannot be done earlier,
 	 * we need complete FIT image in RAM first */
 	if (genimg_get_format((void *) addr) == IMAGE_FORMAT_FIT) {
-		if (!fit_check_format(fit_hdr)) {
+		if (fit_check_format(fit_hdr, IMAGE_SIZE_INVAL)) {
 			bootstage_error(BOOTSTAGE_ID_IDE_FIT_READ);
 			puts("** Bad FIT image format\n");
 			return 1;
diff --git a/cmd/fpga.c b/cmd/fpga.c
index 8ae1c936..51410a8e 100644
--- a/cmd/fpga.c
+++ b/cmd/fpga.c
@@ -330,7 +330,7 @@ static int do_fpga_loadmk(struct cmd_tbl *cmdtp, int flag, int argc,
 			return CMD_RET_FAILURE;
 		}
 
-		if (!fit_check_format(fit_hdr)) {
+		if (fit_check_format(fit_hdr, IMAGE_SIZE_INVAL)) {
 			puts("Bad FIT image format\n");
 			return CMD_RET_FAILURE;
 		}
diff --git a/cmd/nand.c b/cmd/nand.c
index 92d039af..97e117a9 100644
--- a/cmd/nand.c
+++ b/cmd/nand.c
@@ -917,7 +917,7 @@ static int nand_load_image(struct cmd_tbl *cmdtp, struct mtd_info *mtd,
 #if defined(CONFIG_FIT)
 	/* This cannot be done earlier, we need complete FIT image in RAM first */
 	if (genimg_get_format ((void *)addr) == IMAGE_FORMAT_FIT) {
-		if (!fit_check_format (fit_hdr)) {
+		if (fit_check_format(fit_hdr, IMAGE_SIZE_INVAL)) {
 			bootstage_error(BOOTSTAGE_ID_NAND_FIT_READ);
 			puts ("** Bad FIT image format\n");
 			return 1;
diff --git a/cmd/source.c b/cmd/source.c
index b6c709a3..71f71528 100644
--- a/cmd/source.c
+++ b/cmd/source.c
@@ -107,7 +107,7 @@ int image_source_script(ulong addr, const char *fit_uname)
 #if defined(CONFIG_FIT)
 	case IMAGE_FORMAT_FIT:
 		fit_hdr = buf;
-		if (!fit_check_format (fit_hdr)) {
+		if (fit_check_format(fit_hdr, IMAGE_SIZE_INVAL)) {
 			puts ("Bad FIT image format\n");
 			return 1;
 		}
diff --git a/cmd/ximg.c b/cmd/ximg.c
index 159ba516..ef738ebf 100644
--- a/cmd/ximg.c
+++ b/cmd/ximg.c
@@ -136,7 +136,7 @@ do_imgextract(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 			"at %08lx ...\n", uname, addr);
 
 		fit_hdr = (const void *)addr;
-		if (!fit_check_format(fit_hdr)) {
+		if (fit_check_format(fit_hdr, IMAGE_SIZE_INVAL)) {
 			puts("Bad FIT image format\n");
 			return 1;
 		}
diff --git a/common/image-fdt.c b/common/image-fdt.c
index b63e772b..0b770e27 100644
--- a/common/image-fdt.c
+++ b/common/image-fdt.c
@@ -399,7 +399,7 @@ int boot_get_fdt(int flag, int argc, char *const argv[], uint8_t arch,
 			 */
 #if CONFIG_IS_ENABLED(FIT)
 			/* check FDT blob vs FIT blob */
-			if (fit_check_format(buf)) {
+			if (!fit_check_format(buf, IMAGE_SIZE_INVAL)) {
 				ulong load, len;
 
 				fdt_noffset = boot_get_fdt_fit(images,
diff --git a/common/image-fit.c b/common/image-fit.c
index 1ece100a..470321c5 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -8,6 +8,8 @@
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  */
 
+#define LOG_CATEGORY LOGC_BOOT
+
 #ifdef USE_HOSTCC
 #include "mkimage.h"
 #include <time.h>
@@ -1533,40 +1535,39 @@ int fit_image_check_comp(const void *fit, int noffset, uint8_t comp)
 	return (comp == image_comp);
 }
 
-/**
- * fit_check_format - sanity check FIT image format
- * @fit: pointer to the FIT format image header
- *
- * fit_check_format() runs a basic sanity FIT image verification.
- * Routine checks for mandatory properties, nodes, etc.
- *
- * returns:
- *     1, on success
- *     0, on failure
- */
-int fit_check_format(const void *fit)
+int fit_check_format(const void *fit, ulong size)
 {
+	int ret;
+        
+	/* A FIT image must be a valid FDT */
+	ret = fdt_check_header(fit);
+	if (ret) {
+		log_debug("Wrong FIT format: not a flattened device tree (err=%d)\n",
+			  ret);
+		return -ENOEXEC;
+	}
+
 	/* mandatory / node 'description' property */
-	if (fdt_getprop(fit, 0, FIT_DESC_PROP, NULL) == NULL) {
-		debug("Wrong FIT format: no description\n");
-		return 0;
+	if (!fdt_getprop(fit, 0, FIT_DESC_PROP, NULL)) {
+		log_debug("Wrong FIT format: no description\n");
+		return -ENOMSG;
 	}
 
 	if (IMAGE_ENABLE_TIMESTAMP) {
 		/* mandatory / node 'timestamp' property */
-		if (fdt_getprop(fit, 0, FIT_TIMESTAMP_PROP, NULL) == NULL) {
-			debug("Wrong FIT format: no timestamp\n");
-			return 0;
+		if (!fdt_getprop(fit, 0, FIT_TIMESTAMP_PROP, NULL)) {
+			log_debug("Wrong FIT format: no timestamp\n");
+			return -ENODATA;
 		}
 	}
 
 	/* mandatory subimages parent '/images' node */
 	if (fdt_path_offset(fit, FIT_IMAGES_PATH) < 0) {
-		debug("Wrong FIT format: no images parent node\n");
-		return 0;
+		log_debug("Wrong FIT format: no images parent node\n");
+		return -ENOENT;
 	}
 
-	return 1;
+	return 0;
 }
 
 
@@ -1899,7 +1900,7 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 	printf("## Loading %s from FIT Image at %08lx ...\n", prop_name, addr);
 
 	bootstage_mark(bootstage_id + BOOTSTAGE_SUB_FORMAT);
-	if (!fit_check_format(fit)) {
+	if (fit_check_format(fit, IMAGE_SIZE_INVAL)) {
 		printf("Bad FIT %s image format!\n", prop_name);
 		bootstage_error(bootstage_id + BOOTSTAGE_SUB_FORMAT);
 		return -ENOEXEC;
diff --git a/common/splash_source.c b/common/splash_source.c
index f51ca5dd..bad9a779 100644
--- a/common/splash_source.c
+++ b/common/splash_source.c
@@ -336,10 +336,10 @@ static int splash_load_fit(struct splash_location *location, u32 bmp_load_addr)
 	if (res < 0)
 		return res;
 
-	res = fit_check_format(fit_header);
-	if (!res) {
+	res = fit_check_format(fit_header, IMAGE_SIZE_INVAL);
+	if (res) {
 		debug("Could not find valid FIT image\n");
-		return -EINVAL;
+		return res;
 	}
 
 	/* Get the splash image node */
diff --git a/common/update.c b/common/update.c
index c8dd346a..12626706 100644
--- a/common/update.c
+++ b/common/update.c
@@ -282,7 +282,7 @@ int update_tftp(ulong addr, char *interface, char *devstring)
 got_update_file:
 	fit = (void *)addr;
 
-	if (!fit_check_format((void *)fit)) {
+	if (fit_check_format((void *)fit, IMAGE_SIZE_INVAL)) {
 		printf("Bad FIT format of the update file, aborting "
 							"auto-update\n");
 		return 1;
diff --git a/drivers/fpga/socfpga_arria10.c b/drivers/fpga/socfpga_arria10.c
index dfd3cbb4..c80c4bc3 100644
--- a/drivers/fpga/socfpga_arria10.c
+++ b/drivers/fpga/socfpga_arria10.c
@@ -564,10 +564,10 @@ static int first_loading_rbf_to_buffer(struct udevice *dev,
 	if (ret < 0)
 		return ret;
 
-	ret = fit_check_format(buffer_p);
-	if (!ret) {
+	ret = fit_check_format(buffer_p, IMAGE_SIZE_INVAL);
+	if (ret) {
 		debug("FPGA: No valid FIT image was found.\n");
-		return -EBADF;
+		return ret;
 	}
 
 	confs_noffset = fdt_path_offset(buffer_p, FIT_CONFS_PATH);
diff --git a/drivers/net/fsl-mc/mc.c b/drivers/net/fsl-mc/mc.c
index e516c3c1..c7df8d24 100644
--- a/drivers/net/fsl-mc/mc.c
+++ b/drivers/net/fsl-mc/mc.c
@@ -141,7 +141,7 @@ int parse_mc_firmware_fit_image(u64 mc_fw_addr,
 		return -EINVAL;
 	}
 
-	if (!fit_check_format(fit_hdr)) {
+	if (fit_check_format(fit_hdr, IMAGE_SIZE_INVAL)) {
 		printf("fsl-mc: ERR: Bad firmware image (bad FIT header)\n");
 		return -EINVAL;
 	}
diff --git a/drivers/net/pfe_eth/pfe_firmware.c b/drivers/net/pfe_eth/pfe_firmware.c
index 0493cfe8..b0ef83c5 100644
--- a/drivers/net/pfe_eth/pfe_firmware.c
+++ b/drivers/net/pfe_eth/pfe_firmware.c
@@ -154,7 +154,7 @@ static int pfe_fit_check(void)
 		return ret;
 	}
 
-	if (!fit_check_format(pfe_fit_addr)) {
+	if (fit_check_format(pfe_fit_addr, IMAGE_SIZE_INVAL)) {
 		printf("PFE Firmware: Bad firmware image (bad FIT header)\n");
 		ret = -1;
 		return ret;
diff --git a/include/image.h b/include/image.h
index ad81dad4..2ea5a685 100644
--- a/include/image.h
+++ b/include/image.h
@@ -116,6 +116,9 @@ extern ulong image_load_addr;		/* Default Load Address */
 extern ulong image_save_addr;		/* Default Save Address */
 extern ulong image_save_size;		/* Default Save Size */
 
+/* An invalid size, meaning that the image size is not known */
+#define IMAGE_SIZE_INVAL	(-1UL)
+
 enum ih_category {
 	IH_ARCH,
 	IH_COMP,
@@ -1112,7 +1115,23 @@ int fit_image_check_os(const void *fit, int noffset, uint8_t os);
 int fit_image_check_arch(const void *fit, int noffset, uint8_t arch);
 int fit_image_check_type(const void *fit, int noffset, uint8_t type);
 int fit_image_check_comp(const void *fit, int noffset, uint8_t comp);
-int fit_check_format(const void *fit);
+
+/**
+ * fit_check_format() - Check that the FIT is valid
+ *
+ * This performs various checks on the FIT to make sure it is suitable for
+ * use, looking for mandatory properties, nodes, etc.
+ *
+ * If FIT_FULL_CHECK is enabled, it also runs it through libfdt to make
+ * sure that there are no strange tags or broken nodes in the FIT.
+ *
+ * @fit: pointer to the FIT format image header
+ * @return 0 if OK, -ENOEXEC if not an FDT file, -EINVAL if the full FDT check
+ *	failed (e.g. due to bad structure), -ENOMSG if the description is
+ *	missing, -ENODATA if the timestamp is missing, -ENOENT if the /images
+ *	path is missing
+ */
+int fit_check_format(const void *fit, ulong size);
 
 int fit_conf_find_compat(const void *fit, const void *fdt);
 
diff --git a/tools/fit_common.c b/tools/fit_common.c
index cdf987d3..52b63296 100644
--- a/tools/fit_common.c
+++ b/tools/fit_common.c
@@ -26,7 +26,8 @@
 int fit_verify_header(unsigned char *ptr, int image_size,
 			struct image_tool_params *params)
 {
-	if (fdt_check_header(ptr) != EXIT_SUCCESS || !fit_check_format(ptr))
+	if (fdt_check_header(ptr) != EXIT_SUCCESS ||
+	    fit_check_format(ptr, IMAGE_SIZE_INVAL))
 		return EXIT_FAILURE;
 
 	return EXIT_SUCCESS;
diff --git a/tools/fit_image.c b/tools/fit_image.c
index a082d938..44990822 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -883,7 +883,7 @@ static int fit_extract_contents(void *ptr, struct image_tool_params *params)
 	/* Indent string is defined in header image.h */
 	p = IMAGE_INDENT_STRING;
 
-	if (!fit_check_format(fit)) {
+	if (fit_check_format(fit, IMAGE_SIZE_INVAL)) {
 		printf("Bad FIT image format\n");
 		return -1;
 	}
diff --git a/tools/mkimage.h b/tools/mkimage.h
index 5b096a54..0d314844 100644
--- a/tools/mkimage.h
+++ b/tools/mkimage.h
@@ -29,6 +29,8 @@
 #define debug(fmt,args...)
 #endif /* MKIMAGE_DEBUG */
 
+#define log_debug(fmt, args...)	debug(fmt, ##args)
+
 static inline void *map_sysmem(ulong paddr, unsigned long len)
 {
 	return (void *)(uintptr_t)paddr;
-- 
2.23.0

