Btrfs: check btree node's nritems (053ab70f) · Commits · 戴 / test

When btree node (level = 1) has nritems which equals to zero, we can end up with panic due to insert_ptr()'s BUG_ON(slot > nritems); where slot is 1 and nritems is 0, as copy_for_split() calls insert_ptr(.., path->slots[1] + 1, ...); A invalid value results in the whole mess, this adds the check for btree's node nritems so that we stop reading block when when something is wrong. Signed-off-by:

Liu Bo <bo.li.liu@oracle.com> Reviewed-by:

David Sterba <dsterba@suse.com> Signed-off-by:

Chris Mason <clm@fb.com>

fs/btrfs/disk-io.c

+16 −0

Original line number	Diff line number	Diff line
		@@ -613,6 +613,19 @@ static noinline int check_leaf(struct btrfs_root *root,
		return 0;
		}

		static int check_node(struct btrfs_root root, struct extent_buffer node)
		{
		unsigned long nr = btrfs_header_nritems(node);

		if (nr == 0 \|\| nr > BTRFS_NODEPTRS_PER_BLOCK(root)) {
		btrfs_crit(root->fs_info,
		"corrupt node: block %llu root %llu nritems %lu",
		node->start, root->objectid, nr);
		return -EIO;
		}
		return 0;
		}

		static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
		u64 phy_offset, struct page *page,
		u64 start, u64 end, int mirror)
		@@ -683,6 +696,9 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
		ret = -EIO;
		}

		if (found_level > 0 && check_node(root, eb))
		ret = -EIO;

		if (!ret)
		set_extent_buffer_uptodate(eb);
		err:

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