[PATCH v3 1/7] Btrfs: add a helper to retrive extent inline ref type
From: Liu Bo <hidden>
Date: 2017-08-18 22:17:13
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
An invalid value of extent inline ref type may be read from a malicious image which may force btrfs to crash. This adds a helper which does sanity check for the ref type, so we can know if it's sane, return type if so, otherwise return an error. Signed-off-by: Liu Bo <redacted> --- fs/btrfs/ctree.h | 11 +++++++++++ fs/btrfs/extent-tree.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3f3eb7b..714e779 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h@@ -2561,6 +2561,17 @@ static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping) /* extent-tree.c */ +enum btrfs_inline_ref_type { + BTRFS_REF_TYPE_INVALID = 0, + BTRFS_REF_TYPE_BLOCK = 1, + BTRFS_REF_TYPE_DATA = 2, + BTRFS_REF_TYPE_ANY = 3, +}; + +int btrfs_get_extent_inline_ref_type(struct extent_buffer *eb, + struct btrfs_extent_inline_ref *iref, + enum btrfs_inline_ref_type is_data); + u64 btrfs_csum_bytes_to_leaves(struct btrfs_fs_info *fs_info, u64 csum_bytes); static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_fs_info *fs_info,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index e3b0b41..c540578 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c@@ -1148,6 +1148,43 @@ static int convert_extent_item_v0(struct btrfs_trans_handle *trans, } #endif +/* + * is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required, + * is_data == BTRFS_REF_TYPE_DATA, data type is requried, + * is_data == BTRFS_REF_TYPE_ANY, either type is OK. + */ +int btrfs_get_extent_inline_ref_type(struct extent_buffer *eb, + struct btrfs_extent_inline_ref *iref, + enum btrfs_inline_ref_type is_data) +{ + int type = btrfs_extent_inline_ref_type(eb, iref); + + if (type == BTRFS_TREE_BLOCK_REF_KEY || + type == BTRFS_SHARED_BLOCK_REF_KEY || + type == BTRFS_SHARED_DATA_REF_KEY || + type == BTRFS_EXTENT_DATA_REF_KEY) { + if (is_data == BTRFS_REF_TYPE_BLOCK) { + if (type == BTRFS_TREE_BLOCK_REF_KEY || + type == BTRFS_SHARED_BLOCK_REF_KEY) + return type; + } else if (is_data == BTRFS_REF_TYPE_DATA) { + if (type == BTRFS_EXTENT_DATA_REF_KEY || + type == BTRFS_SHARED_DATA_REF_KEY) + return type; + } else { + ASSERT(is_data == BTRFS_REF_TYPE_ANY); + return type; + } + } + + btrfs_print_leaf(eb->fs_info, eb); + btrfs_err(eb->fs_info, "eb %llu invalid extent inline ref type %d", + eb->start, type); + WARN_ON(1); + + return BTRFS_REF_TYPE_INVALID; +} + static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset) { u32 high_crc = ~(u32)0;
--
2.9.4