From 2615aca92c628457fe76131a5f810720349dc4c5 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Thu, 8 Feb 2018 08:59:40 +0800 Subject: btrfs-progs: ctree: Add extra level check for read_node_slot() Strangely, we have level check in btrfs_print_tree() while we don't have the same check in read_node_slot(). That's to say, for the following corruption, btrfs_search_slot() or btrfs_next_leaf() can return invalid leaf: Parent eb: node XXXXXX level 1 ^^^^^^^ Child should be leaf (level 0) ... key (XXX XXX XXX) block YYYYYY Child eb: leaf YYYYYY level 1 ^^^^^^^ Something went wrong now And for the corrupted leaf returned, later caller can be screwed up easily. Reported-by: Ralph Gauges Signed-off-by: Qu Wenruo Reviewed-by: Nikolay Borisov Signed-off-by: David Sterba --- ctree.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/ctree.c b/ctree.c index 45b368ce..e26a1c29 100644 --- a/ctree.c +++ b/ctree.c @@ -22,6 +22,7 @@ #include "repair.h" #include "internal.h" #include "sizes.h" +#include "messages.h" static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int level); @@ -642,7 +643,9 @@ static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, struct extent_buffer *read_node_slot(struct btrfs_fs_info *fs_info, struct extent_buffer *parent, int slot) { + struct extent_buffer *ret; int level = btrfs_header_level(parent); + if (slot < 0) return NULL; if (slot >= btrfs_header_nritems(parent)) @@ -651,8 +654,20 @@ struct extent_buffer *read_node_slot(struct btrfs_fs_info *fs_info, if (level == 0) return NULL; - return read_tree_block(fs_info, btrfs_node_blockptr(parent, slot), + ret = read_tree_block(fs_info, btrfs_node_blockptr(parent, slot), btrfs_node_ptr_generation(parent, slot)); + if (!extent_buffer_uptodate(ret)) + return ERR_PTR(-EIO); + + if (btrfs_header_level(ret) != level - 1) { + error( +"child eb corrupted: parent bytenr=%llu item=%d parent level=%d child level=%d", + btrfs_header_bytenr(parent), slot, + btrfs_header_level(parent), btrfs_header_level(ret)); + free_extent_buffer(ret); + return ERR_PTR(-EIO); + } + return ret; } static int balance_level(struct btrfs_trans_handle *trans, -- cgit v1.2.3