From: Simon Glass <sjg@chromium.org>
Date: Tue, 16 Feb 2021 00:08:09 +0000 (-0700)
Subject: [PATCH] image: Adjust the workings of fit_check_format()
X-Git-Tag: archive/raspbian/2021.01+dfsg-5+rpi1+deb11u2^2~4
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=b77a4bcd34a6276213bbca031f802fe371aaa6ad;p=u-boot.git

[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>

This patch includes this one as well:
https://github.com/u-boot/u-boot/commit/ea1a9ec5f430359720d9a0621ed1acfbba6a142a.patch

Reviewed-By: Daniel Leidert <dleidert@debian.org>
Origin: https://github.com/u-boot/u-boot/commit/c5819701a3de61e2ba2ef7ad0b616565b32305e5
Origin: https://github.com/u-boot/u-boot/commit/ea1a9ec5f430359720d9a0621ed1acfbba6a142a
Bug: https://github.com/advisories/GHSA-3w66-96j7-fmcp
Bug-Debian: https://bugs.debian.org/983270
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2021-27097
Bug-Freexian-Security: https://deb.freexian.com/extended-lts/tracker/CVE-2021-27097

Gbp-Pq: Name CVE-2021-27097-2.patch
---

diff --git a/arch/arm/cpu/armv8/sec_firmware.c b/arch/arm/cpu/armv8/sec_firmware.c
index bfc0fac3e..0561f5efd 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 e6b0e0441..a0f823f96 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 8060e753e..3195db912 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 8ae1c936f..51410a8e4 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 92d039af8..97e117a97 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 b6c709a3d..71f71528a 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 159ba5164..ef738ebfa 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 327a8c4c3..410525921 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 abceae44e..442433e55 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>
@@ -1550,40 +1552,39 @@ 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;
 }
 
 
@@ -1923,7 +1924,7 @@ 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 f51ca5ddf..bad9a7790 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 a5879cb52..f0848954e 100644
--- a/common/update.c
+++ b/common/update.c
@@ -286,7 +286,7 @@ int update_tftp(ulong addr, char *interface, char *devstring)
 got_update_file:
 	fit = map_sysmem(addr, 0);
 
-	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;
@@ -363,7 +363,7 @@ int fit_update(const void *fit)
 	if (!fit)
 		return -EINVAL;
 
-	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 -EINVAL;
 	}
diff --git a/drivers/fpga/socfpga_arria10.c b/drivers/fpga/socfpga_arria10.c
index 44e1ac54c..18f99676d 100644
--- a/drivers/fpga/socfpga_arria10.c
+++ b/drivers/fpga/socfpga_arria10.c
@@ -565,10 +565,10 @@ 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 84db6be62..81265ee35 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 41999e176..eee70a2e7 100644
--- a/drivers/net/pfe_eth/pfe_firmware.c
+++ b/drivers/net/pfe_eth/pfe_firmware.c
@@ -160,7 +160,7 @@ 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 41473dbb9..8c152c5c5 100644
--- a/include/image.h
+++ b/include/image.h
@@ -134,6 +134,9 @@ 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,
@@ -1141,7 +1144,23 @@ 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 cdf987d3c..52b63296f 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 06faeda7c..d440d143c 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 5b096a545..0d3148444 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;