4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Qu Wenruo <[email protected]> commit 7f43d4affb2a254d421ab20b0cf65ac2569909fb upstream. Function check_leaf() checks if any item pointer points outside of the leaf, but it doesn't check if the pointer overlaps with the item itself. Normally only the last item may be the victim, but adding such check is never a bad idea anyway. Signed-off-by: Qu Wenruo <[email protected]> Reviewed-by: Nikolay Borisov <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/btrfs/disk-io.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -621,6 +621,13 @@ static noinline int check_leaf(struct bt return -EUCLEAN; } + /* Also check if the item pointer overlaps with btrfs item. */ + if (btrfs_item_nr_offset(slot) + sizeof(struct btrfs_item) > + btrfs_item_ptr_offset(leaf, slot)) { + CORRUPT("slot overlap with its data", leaf, root, slot); + return -EUCLEAN; + } + prev_key.objectid = key.objectid; prev_key.type = key.type; prev_key.offset = key.offset;
