From 0d2c2d480918eb2b939ebcc6057548d4d808d829 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 30 Aug 2016 15:22:13 +0800 Subject: [PATCH] btrfs-progs: fsck: Check drop level before walking through fs tree Exposed by fuzzed image from Lukas, which contains invalid drop level (16), causing segfault when accessing path->nodes[drop_level]. This patch will check drop level against fs tree level and BTRFS_MAX_LEVEL to avoid such problem. Reported-by: Lukas Lueg Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- cmds-check.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/cmds-check.c b/cmds-check.c index 1e1f7c9..2aa0a7b 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -3742,6 +3742,11 @@ static int check_fs_root(struct btrfs_root *root, btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); level = root_item->drop_level; path.lowest_level = level; + if (level > btrfs_header_level(root->node) || + level >= BTRFS_MAX_LEVEL) { + error("ignoring invalid drop level: %u", level); + goto skip_walking; + } wret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); if (wret < 0) goto skip_walking; -- 2.7.4