// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) Qu Wenruo 2017. All rights reserved. */ /* * The module is used to catch unexpected/corrupted tree block data. * Such behavior can be caused either by a fuzzed image or bugs. * * The objective is to do leaf/node validation checks when tree block is read * from disk, and check *every* possible member, so other code won't * need to checking them again. * * Due to the potential and unwanted damage, every checker needs to be * carefully reviewed otherwise so it does not prevent mount of valid images. */ #include "ctree.h" #include "tree-checker.h" #include "disk-io.h" #include "compression.h" #include "volumes.h" /* * Error message should follow the following format: * corrupt : , [, ] * * @type: leaf or node * @identifier: the necessary info to locate the leaf/node. * It's recommened to decode key.objecitd/offset if it's * meaningful. * @reason: describe the error * @bad_value: optional, it's recommened to output bad value and its * expected value (range). * * Since comma is used to separate the components, only space is allowed * inside each component. */ /* * Append generic "corrupt leaf/node root=%llu block=%llu slot=%d: " to @fmt. * Allows callers to customize the output. */ __printf(4, 5) __cold static void generic_err(const struct btrfs_fs_info *fs_info, const struct extent_buffer *eb, int slot, const char *fmt, ...) { struct va_format vaf; va_list args; va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; btrfs_crit(fs_info, "corrupt %s: root=%llu block=%llu slot=%d, %pV", btrfs_header_level(eb) == 0 ? "leaf" : "node", btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, &vaf); va_end(args); } /* * Customized reporter for extent data item, since its key objectid and * offset has its own meaning. */ __printf(4, 5) __cold static void file_extent_err(const struct btrfs_fs_info *fs_info, const struct extent_buffer *eb, int slot, const char *fmt, ...) { struct btrfs_key key; struct va_format vaf; va_list args; btrfs_item_key_to_cpu(eb, &key, slot); va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; btrfs_crit(fs_info, "corrupt %s: root=%llu block=%llu slot=%d ino=%llu file_offset=%llu, %pV", btrfs_header_level(eb) == 0 ? "leaf" : "node", btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, key.objectid, key.offset, &vaf); va_end(args); } /* * Return 0 if the btrfs_file_extent_##name is aligned to @alignment * Else return 1 */ #define CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, name, alignment) \ ({ \ if (!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment))) \ file_extent_err((fs_info), (leaf), (slot), \ "invalid %s for file extent, have %llu, should be aligned to %u", \ (#name), btrfs_file_extent_##name((leaf), (fi)), \ (alignment)); \ (!IS_ALIGNED(btrfs_file_extent_##name((leaf), (fi)), (alignment))); \ }) static int check_extent_data_item(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf, struct btrfs_key *key, int slot) { struct btrfs_file_extent_item *fi; u32 sectorsize = fs_info->sectorsize; u32 item_size = btrfs_item_size_nr(leaf, slot); if (!IS_ALIGNED(key->offset, sectorsize)) { file_extent_err(fs_info, leaf, slot, "unaligned file_offset for file extent, have %llu should be aligned to %u", key->offset, sectorsize); return -EUCLEAN; } fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) > BTRFS_FILE_EXTENT_TYPES) { file_extent_err(fs_info, leaf, slot, "invalid type for file extent, have %u expect range [0, %u]", btrfs_file_extent_type(leaf, fi), BTRFS_FILE_EXTENT_TYPES); return -EUCLEAN; } /* * Support for new compression/encrption must introduce incompat flag, * and must be caught in open_ctree(). */ if (btrfs_file_extent_compression(leaf, fi) > BTRFS_COMPRESS_TYPES) { file_extent_err(fs_info, leaf, slot, "invalid compression for file extent, have %u expect range [0, %u]", btrfs_file_extent_compression(leaf, fi), BTRFS_COMPRESS_TYPES); return -EUCLEAN; } if (btrfs_file_extent_encryption(leaf, fi)) { file_extent_err(fs_info, leaf, slot, "invalid encryption for file extent, have %u expect 0", btrfs_file_extent_encryption(leaf, fi)); return -EUCLEAN; } if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) { /* Inline extent must have 0 as key offset */ if (key->offset) { file_extent_err(fs_info, leaf, slot, "invalid file_offset for inline file extent, have %llu expect 0", key->offset); return -EUCLEAN; } /* Compressed inline extent has no on-disk size, skip it */ if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) return 0; /* Uncompressed inline extent size must match item size */ if (item_size != BTRFS_FILE_EXTENT_INLINE_DATA_START + btrfs_file_extent_ram_bytes(leaf, fi)) { file_extent_err(fs_info, leaf, slot, "invalid ram_bytes for uncompressed inline extent, have %u expect %llu", item_size, BTRFS_FILE_EXTENT_INLINE_DATA_START + btrfs_file_extent_ram_bytes(leaf, fi)); return -EUCLEAN; } return 0; } /* Regular or preallocated extent has fixed item size */ if (item_size != sizeof(*fi)) { file_extent_err(fs_info, leaf, slot, "invalid item size for reg/prealloc file extent, have %u expect %zu", item_size, sizeof(*fi)); return -EUCLEAN; } if (CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, ram_bytes, sectorsize) || CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, disk_bytenr, sectorsize) || CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, disk_num_bytes, sectorsize) || CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, offset, sectorsize) || CHECK_FE_ALIGNED(fs_info, leaf, slot, fi, num_bytes, sectorsize)) return -EUCLEAN; return 0; } static int check_csum_item(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf, struct btrfs_key *key, int slot) { u32 sectorsize = fs_info->sectorsize; u32 csumsize = btrfs_super_csum_size(fs_info->super_copy); if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) { generic_err(fs_info, leaf, slot, "invalid key objectid for csum item, have %llu expect %llu", key->objectid, BTRFS_EXTENT_CSUM_OBJECTID); return -EUCLEAN; } if (!IS_ALIGNED(key->offset, sectorsize)) { generic_err(fs_info, leaf, slot, "unaligned key offset for csum item, have %llu should be aligned to %u", key->offset, sectorsize); return -EUCLEAN; } if (!IS_ALIGNED(btrfs_item_size_nr(leaf, slot), csumsize)) { generic_err(fs_info, leaf, slot, "unaligned item size for csum item, have %u should be aligned to %u", btrfs_item_size_nr(leaf, slot), csumsize); return -EUCLEAN; } return 0; } /* * Customized reported for dir_item, only important new info is key->objectid, * which represents inode number */ __printf(4, 5) __cold static void dir_item_err(const struct btrfs_fs_info *fs_info, const struct extent_buffer *eb, int slot, const char *fmt, ...) { struct btrfs_key key; struct va_format vaf; va_list args; btrfs_item_key_to_cpu(eb, &key, slot); va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; btrfs_crit(fs_info, "corrupt %s: root=%llu block=%llu slot=%d ino=%llu, %pV", btrfs_header_level(eb) == 0 ? "leaf" : "node", btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, key.objectid, &vaf); va_end(args); } static int check_dir_item(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf, struct btrfs_key *key, int slot) { struct btrfs_dir_item *di; u32 item_size = btrfs_item_size_nr(leaf, slot); u32 cur = 0; di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); while (cur < item_size) { u32 name_len; u32 data_len; u32 max_name_len; u32 total_size; u32 name_hash; u8 dir_type; /* header itself should not cross item boundary */ if (cur + sizeof(*di) > item_size) { dir_item_err(fs_info, leaf, slot, "dir item header crosses item boundary, have %zu boundary %u", cur + sizeof(*di), item_size); return -EUCLEAN; } /* dir type check */ dir_type = btrfs_dir_type(leaf, di); if (dir_type >= BTRFS_FT_MAX) { dir_item_err(fs_info, leaf, slot, "invalid dir item type, have %u expect [0, %u)", dir_type, BTRFS_FT_MAX); return -EUCLEAN; } if (key->type == BTRFS_XATTR_ITEM_KEY && dir_type != BTRFS_FT_XATTR) { dir_item_err(fs_info, leaf, slot, "invalid dir item type for XATTR key, have %u expect %u", dir_type, BTRFS_FT_XATTR); return -EUCLEAN; } if (dir_type == BTRFS_FT_XATTR && key->type != BTRFS_XATTR_ITEM_KEY) { dir_item_err(fs_info, leaf, slot, "xattr dir type found for non-XATTR key"); return -EUCLEAN; } if (dir_type == BTRFS_FT_XATTR) max_name_len = XATTR_NAME_MAX; else max_name_len = BTRFS_NAME_LEN; /* Name/data length check */ name_len = btrfs_dir_name_len(leaf, di); data_len = btrfs_dir_data_len(leaf, di); if (name_len > max_name_len) { dir_item_err(fs_info, leaf, slot, "dir item name len too long, have %u max %u", name_len, max_name_len); return -EUCLEAN; } if (name_len + data_len > BTRFS_MAX_XATTR_SIZE(fs_info)) { dir_item_err(fs_info, leaf, slot, "dir item name and data len too long, have %u max %u", name_len + data_len, BTRFS_MAX_XATTR_SIZE(fs_info)); return -EUCLEAN; } if (data_len && dir_type != BTRFS_FT_XATTR) { dir_item_err(fs_info, leaf, slot, "dir item with invalid data len, have %u expect 0", data_len); return -EUCLEAN; } total_size = sizeof(*di) + name_len + data_len; /* header and name/data should not cross item boundary */ if (cur + total_size > item_size) { dir_item_err(fs_info, leaf, slot, "dir item data crosses item boundary, have %u boundary %u", cur + total_size, item_size); return -EUCLEAN; } /* * Special check for XATTR/DIR_ITEM, as key->offset is name * hash, should match its name */ if (key->type == BTRFS_DIR_ITEM_KEY || key->type == BTRFS_XATTR_ITEM_KEY) { char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)]; read_extent_buffer(leaf, namebuf, (unsigned long)(di + 1), name_len); name_hash = btrfs_name_hash(namebuf, name_len); if (key->offset != name_hash) { dir_item_err(fs_info, leaf, slot, "name hash mismatch with key, have 0x%016x expect 0x%016llx", name_hash, key->offset); return -EUCLEAN; } } cur += total_size; di = (struct btrfs_dir_item *)((void *)di + total_size); } return 0; } __printf(4, 5) __cold static void block_group_err(const struct btrfs_fs_info *fs_info, const struct extent_buffer *eb, int slot, const char *fmt, ...) { struct btrfs_key key; struct va_format vaf; va_list args; btrfs_item_key_to_cpu(eb, &key, slot); va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; btrfs_crit(fs_info, "corrupt %s: root=%llu block=%llu slot=%d bg_start=%llu bg_len=%llu, %pV", btrfs_header_level(eb) == 0 ? "leaf" : "node", btrfs_header_owner(eb), btrfs_header_bytenr(eb), slot, key.objectid, key.offset, &vaf); va_end(args); } static int check_block_group_item(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf, struct btrfs_key *key, int slot) { struct btrfs_block_group_item bgi; u32 item_size = btrfs_item_size_nr(leaf, slot); u64 flags; u64 type; /* * Here we don't really care about alignment since extent allocator can * handle it. We care more about the size, as if one block group is * larger than maximum size, it's must be some obvious corruption. */ if (key->offset > BTRFS_MAX_DATA_CHUNK_SIZE || key->offset == 0) { block_group_err(fs_info, leaf, slot, "invalid block group size, have %llu expect (0, %llu]", key->offset, BTRFS_MAX_DATA_CHUNK_SIZE); return -EUCLEAN; } if (item_size != sizeof(bgi)) { block_group_err(fs_info, leaf, slot, "invalid item size, have %u expect %zu", item_size, sizeof(bgi)); return -EUCLEAN; } read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot), sizeof(bgi)); if (btrfs_block_group_chunk_objectid(&bgi) != BTRFS_FIRST_CHUNK_TREE_OBJECTID) { block_group_err(fs_info, leaf, slot, "invalid block group chunk objectid, have %llu expect %llu", btrfs_block_group_chunk_objectid(&bgi), BTRFS_FIRST_CHUNK_TREE_OBJECTID); return -EUCLEAN; } if (btrfs_block_group_used(&bgi) > key->offset) { block_group_err(fs_info, leaf, slot, "invalid block group used, have %llu expect [0, %llu)", btrfs_block_group_used(&bgi), key->offset); return -EUCLEAN; } flags = btrfs_block_group_flags(&bgi); if (hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) > 1) { block_group_err(fs_info, leaf, slot, "invalid profile flags, have 0x%llx (%lu bits set) expect no more than 1 bit set", flags & BTRFS_BLOCK_GROUP_PROFILE_MASK, hweight64(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)); return -EUCLEAN; } type = flags & BTRFS_BLOCK_GROUP_TYPE_MASK; if (type != BTRFS_BLOCK_GROUP_DATA && type != BTRFS_BLOCK_GROUP_METADATA && type != BTRFS_BLOCK_GROUP_SYSTEM && type != (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA)) { block_group_err(fs_info, leaf, slot, "invalid type, have 0x%llx (%lu bits set) expect either 0x%llx, 0x%llx, 0x%llu or 0x%llx", type, hweight64(type), BTRFS_BLOCK_GROUP_DATA, BTRFS_BLOCK_GROUP_METADATA, BTRFS_BLOCK_GROUP_SYSTEM, BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA); return -EUCLEAN; } return 0; } /* * Common point to switch the item-specific validation. */ static int check_leaf_item(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf, struct btrfs_key *key, int slot) { int ret = 0; switch (key->type) { case BTRFS_EXTENT_DATA_KEY: ret = check_extent_data_item(fs_info, leaf, key, slot); break; case BTRFS_EXTENT_CSUM_KEY: ret = check_csum_item(fs_info, leaf, key, slot); break; case BTRFS_DIR_ITEM_KEY: case BTRFS_DIR_INDEX_KEY: case BTRFS_XATTR_ITEM_KEY: ret = check_dir_item(fs_info, leaf, key, slot); break; case BTRFS_BLOCK_GROUP_ITEM_KEY: ret = check_block_group_item(fs_info, leaf, key, slot); break; } return ret; } static int check_leaf(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf, bool check_item_data) { /* No valid key type is 0, so all key should be larger than this key */ struct btrfs_key prev_key = {0, 0, 0}; struct btrfs_key key; u32 nritems = btrfs_header_nritems(leaf); int slot; /* * Extent buffers from a relocation tree have a owner field that * corresponds to the subvolume tree they are based on. So just from an * extent buffer alone we can not find out what is the id of the * corresponding subvolume tree, so we can not figure out if the extent * buffer corresponds to the root of the relocation tree or not. So * skip this check for relocation trees. */ if (nritems == 0 && !btrfs_header_flag(leaf, BTRFS_HEADER_FLAG_RELOC)) { u64 owner = btrfs_header_owner(leaf); struct btrfs_root *check_root; /* These trees must never be empty */ if (owner == BTRFS_ROOT_TREE_OBJECTID || owner == BTRFS_CHUNK_TREE_OBJECTID || owner == BTRFS_EXTENT_TREE_OBJECTID || owner == BTRFS_DEV_TREE_OBJECTID || owner == BTRFS_FS_TREE_OBJECTID || owner == BTRFS_DATA_RELOC_TREE_OBJECTID) { generic_err(fs_info, leaf, 0, "invalid root, root %llu must never be empty", owner); return -EUCLEAN; } key.objectid = owner; key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; check_root = btrfs_get_fs_root(fs_info, &key, false); /* * The only reason we also check NULL here is that during * open_ctree() some roots has not yet been set up. */ if (!IS_ERR_OR_NULL(check_root)) { struct extent_buffer *eb; eb = btrfs_root_node(check_root); /* if leaf is the root, then it's fine */ if (leaf != eb) { generic_err(fs_info, leaf, 0, "invalid nritems, have %u should not be 0 for non-root leaf", nritems); free_extent_buffer(eb); return -EUCLEAN; } free_extent_buffer(eb); } return 0; } if (nritems == 0) return 0; /* * Check the following things to make sure this is a good leaf, and * leaf users won't need to bother with similar sanity checks: * * 1) key ordering * 2) item offset and size * No overlap, no hole, all inside the leaf. * 3) item content * If possible, do comprehensive sanity check. * NOTE: All checks must only rely on the item data itself. */ for (slot = 0; slot < nritems; slot++) { u32 item_end_expected; int ret; btrfs_item_key_to_cpu(leaf, &key, slot); /* Make sure the keys are in the right order */ if (btrfs_comp_cpu_keys(&prev_key, &key) >= 0) { generic_err(fs_info, leaf, slot, "bad key order, prev (%llu %u %llu) current (%llu %u %llu)", prev_key.objectid, prev_key.type, prev_key.offset, key.objectid, key.type, key.offset); return -EUCLEAN; } /* * Make sure the offset and ends are right, remember that the * item data starts at the end of the leaf and grows towards the * front. */ if (slot == 0) item_end_expected = BTRFS_LEAF_DATA_SIZE(fs_info); else item_end_expected = btrfs_item_offset_nr(leaf, slot - 1); if (btrfs_item_end_nr(leaf, slot) != item_end_expected) { generic_err(fs_info, leaf, slot, "unexpected item end, have %u expect %u", btrfs_item_end_nr(leaf, slot), item_end_expected); return -EUCLEAN; } /* * Check to make sure that we don't point outside of the leaf, * just in case all the items are consistent to each other, but * all point outside of the leaf. */ if (btrfs_item_end_nr(leaf, slot) > BTRFS_LEAF_DATA_SIZE(fs_info)) { generic_err(fs_info, leaf, slot, "slot end outside of leaf, have %u expect range [0, %u]", btrfs_item_end_nr(leaf, slot), BTRFS_LEAF_DATA_SIZE(fs_info)); return -EUCLEAN; } /* Also check if the item pointer overlaps with btrfs item. */ if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) > btrfs_item_ptr_offset(leaf, slot)) { generic_err(fs_info, leaf, slot, "slot overlaps with its data, item end %lu data start %lu", btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item), btrfs_item_ptr_offset(leaf, slot)); return -EUCLEAN; } if (check_item_data) { /* * Check if the item size and content meet other * criteria */ ret = check_leaf_item(fs_info, leaf, &key, slot); if (ret < 0) return ret; } prev_key.objectid = key.objectid; prev_key.type = key.type; prev_key.offset = key.offset; } return 0; } int btrfs_check_leaf_full(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf) { return check_leaf(fs_info, leaf, true); } int btrfs_check_leaf_relaxed(struct btrfs_fs_info *fs_info, struct extent_buffer *leaf) { return check_leaf(fs_info, leaf, false); } int btrfs_check_node(struct btrfs_fs_info *fs_info, struct extent_buffer *node) { unsigned long nr = btrfs_header_nritems(node); struct btrfs_key key, next_key; int slot; u64 bytenr; int ret = 0; if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(fs_info)) { btrfs_crit(fs_info, "corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]", btrfs_header_owner(node), node->start, nr == 0 ? "small" : "large", nr, BTRFS_NODEPTRS_PER_BLOCK(fs_info)); return -EUCLEAN; } for (slot = 0; slot < nr - 1; slot++) { bytenr = btrfs_node_blockptr(node, slot); btrfs_node_key_to_cpu(node, &key, slot); btrfs_node_key_to_cpu(node, &next_key, slot + 1); if (!bytenr) { generic_err(fs_info, node, slot, "invalid NULL node pointer"); ret = -EUCLEAN; goto out; } if (!IS_ALIGNED(bytenr, fs_info->sectorsize)) { generic_err(fs_info, node, slot, "unaligned pointer, have %llu should be aligned to %u", bytenr, fs_info->sectorsize); ret = -EUCLEAN; goto out; } if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) { generic_err(fs_info, node, slot, "bad key order, current (%llu %u %llu) next (%llu %u %llu)", key.objectid, key.type, key.offset, next_key.objectid, next_key.type, next_key.offset); ret = -EUCLEAN; goto out; } } out: return ret; }