Btrfs: add a helper to retrive extent inline ref type

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 he type, otherwise return an error.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minimal tweak const types, causing warnings due to other cleanup patches ]
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Liu Bo 2017-08-18 15:15:18 -06:00 committed by David Sterba
parent af1cbe0a66
commit 167ce953ca
2 changed files with 48 additions and 0 deletions

View file

@ -2567,6 +2567,17 @@ 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(const 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,

View file

@ -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(const 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((struct extent_buffer *)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;