From 11dcc86ebac88ca878e661eab4ce2a5a6c611edd Mon Sep 17 00:00:00 2001 From: David Sterba Date: Wed, 24 Jan 2024 22:41:01 +0100 Subject: [PATCH] btrfs: handle invalid extent item reference found in extent_from_logical() The extent_from_logical() helper looks up an extent item by a key, allowing to do an inexact search when key->offset is -1. It's never expected to find such item, as it would break the allowed range of a extent item offset. The same error is already handled in btrfs_backref_iter_start() so add a comment for consistency. Signed-off-by: David Sterba --- fs/btrfs/backref.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 0fa27ed802f6..6ba743ddfe21 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -2227,6 +2227,13 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) return ret; + if (ret == 0) { + /* + * Key with offset -1 found, there would have to exist an extent + * item with such offset, but this is out of the valid range. + */ + return -EUCLEAN; + } ret = btrfs_previous_extent_item(extent_root, path, 0); if (ret) { @@ -2870,6 +2877,10 @@ int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr) if (ret < 0) return ret; if (ret == 0) { + /* + * Key with offset -1 found, there would have to exist an extent + * item with such offset, but this is out of the valid range. + */ ret = -EUCLEAN; goto release; } -- 2.50.1