Reverting an interactive git rebase

If you have just done the rebase, you can try as mentioned here:

git reset --hard ORIG_HEAD

as Jakub Narębski details:

ORIG_HEAD is previous state of HEAD, set by commands that have possibly dangerous behavior, to be easy to revert them.
It is less useful now that Git has reflog: HEAD@{1} is roughly equivalent to ORIG_HEAD (HEAD@{1} is always last value of HEAD, ORIG_HEAD is last value of HEAD before dangerous operation).

If you have executed some operations since the rebase, the reflog can still help.