openwrt/target/linux/generic/files/block/partitions/fit.c
Daniel Golle cf40141b51
kernel: properly handle paging errors in fit partition parser
The uImage.FIT partition uses page mapping without properly handling
paging errors. This can lead to Kernel Oops in case of read errors
while trying to parse uImage.FIT partitions.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2021-08-27 21:32:43 +01:00

257 lines
7.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* fs/partitions/fit.c
* Copyright (C) 2021 Daniel Golle
*
* headers extracted from U-Boot mkimage sources
* (C) Copyright 2008 Semihalf
* (C) Copyright 2000-2005
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* based on existing partition parsers
* Copyright (C) 1991-1998 Linus Torvalds
* Re-organised Feb 1998 Russell King
*/
#define pr_fmt(fmt) fmt
#include <linux/types.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
#include "check.h"
#define FIT_IMAGES_PATH "/images"
#define FIT_CONFS_PATH "/configurations"
/* hash/signature/key node */
#define FIT_HASH_NODENAME "hash"
#define FIT_ALGO_PROP "algo"
#define FIT_VALUE_PROP "value"
#define FIT_IGNORE_PROP "uboot-ignore"
#define FIT_SIG_NODENAME "signature"
#define FIT_KEY_REQUIRED "required"
#define FIT_KEY_HINT "key-name-hint"
/* cipher node */
#define FIT_CIPHER_NODENAME "cipher"
#define FIT_ALGO_PROP "algo"
/* image node */
#define FIT_DATA_PROP "data"
#define FIT_DATA_POSITION_PROP "data-position"
#define FIT_DATA_OFFSET_PROP "data-offset"
#define FIT_DATA_SIZE_PROP "data-size"
#define FIT_TIMESTAMP_PROP "timestamp"
#define FIT_DESC_PROP "description"
#define FIT_ARCH_PROP "arch"
#define FIT_TYPE_PROP "type"
#define FIT_OS_PROP "os"
#define FIT_COMP_PROP "compression"
#define FIT_ENTRY_PROP "entry"
#define FIT_LOAD_PROP "load"
/* configuration node */
#define FIT_KERNEL_PROP "kernel"
#define FIT_FILESYSTEM_PROP "filesystem"
#define FIT_RAMDISK_PROP "ramdisk"
#define FIT_FDT_PROP "fdt"
#define FIT_LOADABLE_PROP "loadables"
#define FIT_DEFAULT_PROP "default"
#define FIT_SETUP_PROP "setup"
#define FIT_FPGA_PROP "fpga"
#define FIT_FIRMWARE_PROP "firmware"
#define FIT_STANDALONE_PROP "standalone"
#define FIT_MAX_HASH_LEN HASH_MAX_DIGEST_SIZE
#define MIN_FREE_SECT 16
#define REMAIN_VOLNAME "rootfs_data"
int parse_fit_partitions(struct parsed_partitions *state, u64 fit_start_sector, u64 sectors, int *slot, int add_remain)
{
struct address_space *mapping = state->bdev->bd_inode->i_mapping;
struct page *page;
void *fit, *init_fit;
struct partition_meta_info *info;
char tmp[sizeof(info->volname)];
u64 dsize, dsectors, imgmaxsect = 0;
u32 size, image_pos, image_len;
const u32 *image_offset_be, *image_len_be, *image_pos_be;
int ret = 1, node, images, config;
const char *image_name, *image_type, *image_description, *config_default,
*config_description, *config_loadables;
int image_name_len, image_type_len, image_description_len, config_default_len,
config_description_len, config_loadables_len;
sector_t start_sect, nr_sects;
size_t label_min;
if (fit_start_sector % (1<<(PAGE_SHIFT - SECTOR_SHIFT)))
return -ERANGE;
page = read_mapping_page(mapping, fit_start_sector >> (PAGE_SHIFT - SECTOR_SHIFT), NULL);
if (IS_ERR(page))
return -EFAULT;
if (PageError(page))
return -EFAULT;
init_fit = page_address(page);
if (!init_fit) {
put_page(page);
return -EFAULT;
}
if (fdt_check_header(init_fit)) {
put_page(page);
return 0;
}
dsectors = get_capacity(state->bdev->bd_disk);
if (sectors)
dsectors = (dsectors>sectors)?sectors:dsectors;
dsize = dsectors << SECTOR_SHIFT;
size = fdt_totalsize(init_fit);
/* silently skip non-external-data legacy FIT images */
if (size > PAGE_SIZE) {
put_page(page);
return 0;
}
if (size >= dsize) {
state->access_beyond_eod = 1;
put_page(page);
return -EFBIG;
}
fit = kmemdup(init_fit, size, GFP_KERNEL);
put_page(page);
if (!fit)
return -ENOMEM;
config = fdt_path_offset(fit, FIT_CONFS_PATH);
if (config < 0) {
printk(KERN_ERR "FIT: Cannot find %s node: %d\n", FIT_CONFS_PATH, images);
ret = -ENOENT;
goto ret_out;
}
config_default = fdt_getprop(fit, config, FIT_DEFAULT_PROP, &config_default_len);
if (!config_default) {
printk(KERN_ERR "FIT: Cannot find default configuration\n");
ret = -ENOENT;
goto ret_out;
}
node = fdt_subnode_offset(fit, config, config_default);
if (node < 0) {
printk(KERN_ERR "FIT: Cannot find %s node: %d\n", config_default, node);
ret = -ENOENT;
goto ret_out;
}
config_description = fdt_getprop(fit, node, FIT_DESC_PROP, &config_description_len);
config_loadables = fdt_getprop(fit, node, FIT_LOADABLE_PROP, &config_loadables_len);
printk(KERN_DEBUG "FIT: Default configuration: \"%s\"%s%s%s\n", config_default,
config_description?" (":"", config_description?:"", config_description?")":"");
images = fdt_path_offset(fit, FIT_IMAGES_PATH);
if (images < 0) {
printk(KERN_ERR "FIT: Cannot find %s node: %d\n", FIT_IMAGES_PATH, images);
ret = -EINVAL;
goto ret_out;
}
fdt_for_each_subnode(node, fit, images) {
image_name = fdt_get_name(fit, node, &image_name_len);
image_type = fdt_getprop(fit, node, FIT_TYPE_PROP, &image_type_len);
image_offset_be = fdt_getprop(fit, node, FIT_DATA_OFFSET_PROP, NULL);
image_pos_be = fdt_getprop(fit, node, FIT_DATA_POSITION_PROP, NULL);
image_len_be = fdt_getprop(fit, node, FIT_DATA_SIZE_PROP, NULL);
if (!image_name || !image_type || !image_len_be)
continue;
image_len = be32_to_cpu(*image_len_be);
if (!image_len)
continue;
if (image_offset_be)
image_pos = be32_to_cpu(*image_offset_be) + size;
else if (image_pos_be)
image_pos = be32_to_cpu(*image_pos_be);
else
continue;
image_description = fdt_getprop(fit, node, FIT_DESC_PROP, &image_description_len);
printk(KERN_DEBUG "FIT: %16s sub-image 0x%08x..0x%08x \"%s\" %s%s%s\n",
image_type, image_pos, image_pos + image_len - 1, image_name,
image_description?"(":"", image_description?:"", image_description?") ":"");
if (strcmp(image_type, FIT_FILESYSTEM_PROP))
continue;
if (image_pos & ((1 << PAGE_SHIFT)-1)) {
printk(KERN_ERR "FIT: image %s start not aligned to page boundaries, skipping\n", image_name);
continue;
}
if (image_len & ((1 << PAGE_SHIFT)-1)) {
printk(KERN_ERR "FIT: sub-image %s end not aligned to page boundaries, skipping\n", image_name);
continue;
}
start_sect = image_pos >> SECTOR_SHIFT;
nr_sects = image_len >> SECTOR_SHIFT;
imgmaxsect = (imgmaxsect < (start_sect + nr_sects))?(start_sect + nr_sects):imgmaxsect;
if (start_sect + nr_sects > dsectors) {
state->access_beyond_eod = 1;
continue;
}
put_partition(state, ++(*slot), fit_start_sector + start_sect, nr_sects);
state->parts[*slot].flags = 0;
info = &state->parts[*slot].info;
label_min = min_t(int, sizeof(info->volname) - 1, image_name_len);
strncpy(info->volname, image_name, label_min);
info->volname[label_min] = '\0';
snprintf(tmp, sizeof(tmp), "(%s)", info->volname);
strlcat(state->pp_buf, tmp, PAGE_SIZE);
state->parts[*slot].has_info = true;
if (config_loadables && !strcmp(image_name, config_loadables)) {
printk(KERN_DEBUG "FIT: selecting configured loadable \"%s\" to be root filesystem\n", image_name);
state->parts[*slot].flags |= ADDPART_FLAG_ROOTDEV;
}
}
if (add_remain && (imgmaxsect + MIN_FREE_SECT) < dsectors) {
put_partition(state, ++(*slot), fit_start_sector + imgmaxsect, dsectors - imgmaxsect);
state->parts[*slot].flags = 0;
info = &state->parts[*slot].info;
strcpy(info->volname, REMAIN_VOLNAME);
snprintf(tmp, sizeof(tmp), "(%s)", REMAIN_VOLNAME);
strlcat(state->pp_buf, tmp, PAGE_SIZE);
}
ret_out:
kfree(fit);
return ret;
}
int fit_partition(struct parsed_partitions *state) {
int slot = 0;
return parse_fit_partitions(state, 0, 0, &slot, 0);
}