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.
v2: add enum type and return BTRFS_REF_TYPE_INVALID instead of -EINVAL
Signed-off-by: Liu Bo <bo.li....@oracle.com>
---
fs/btrfs/ctree.h | 11 +++++++++++
fs/btrfs/extent-tree.c | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 47 insertions(+)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3f3eb7b..9866420 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_types {
+ 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_types 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..83a3cdc 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1148,6 +1148,42 @@ 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_types 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);
+ WARN(1, "eb %llu invalid extent inline ref type %d\n",
+ eb->start, type);
+
+ 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
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