Btrfs: improve check_node to avoid reading corrupted nodes

We need to check items in a node to make sure that we're reading
a valid one, otherwise we could get various crashes while processing
delayed_refs.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Liu Bo 2016-09-14 17:23:24 -07:00 committed by David Sterba
parent a42cbec9c6
commit 6b722c1747

View File

@ -546,9 +546,10 @@ static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
}
#define CORRUPT(reason, eb, root, slot) \
btrfs_crit(root->fs_info, "corrupt leaf, %s: block=%llu," \
"root=%llu, slot=%d", reason, \
btrfs_header_bytenr(eb), root->objectid, slot)
btrfs_crit(root->fs_info, "corrupt %s, %s: block=%llu," \
" root=%llu, slot=%d", \
btrfs_header_level(eb) == 0 ? "leaf" : "node",\
reason, btrfs_header_bytenr(eb), root->objectid, slot)
static noinline int check_leaf(struct btrfs_root *root,
struct extent_buffer *leaf)
@ -635,6 +636,10 @@ static noinline int check_leaf(struct btrfs_root *root,
static int check_node(struct btrfs_root *root, 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(root)) {
btrfs_crit(root->fs_info,
@ -642,7 +647,26 @@ static int check_node(struct btrfs_root *root, struct extent_buffer *node)
node->start, root->objectid, nr);
return -EIO;
}
return 0;
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) {
CORRUPT("invalid item slot", node, root, slot);
ret = -EIO;
goto out;
}
if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) {
CORRUPT("bad key order", node, root, slot);
ret = -EIO;
goto out;
}
}
out:
return ret;
}
static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,