Re: [PATCH v1.5] worktree: Fix out of bounds read that causes data loss and reject invalid empty input in worktree add

[Junio C Hamano <gitster@pobox.com>]

René Scharfe <l.s.r@web.de> writes:

> On 8/12/26 12:46 AM, Junio C Hamano wrote:
>> René Scharfe <l.s.r@web.de> writes:
>> 
>>> From: =?UTF-8?q?Matthias=20A=C3=9Fhauer?= <mha1993@live.de>
>>>
>>> `worktree_basename` tries to read from memory before the passed `path`
>>> string, if `path` is empty (or only consists of directory separators).
>>> That results in unexpected nonsense data being returned to the caller,
>>> which can lead to issues, such as `git worktree add ""` recursively
>>> deleting the current working directory, including `.git`.
>>>
>>> Stop reading out of bounds in these cases to avoid that behaviour.
>>>
>>> This leads to `git worktree add ""` consistently exiting with the
>>> message `BUG: How come '' becomes empty after sanitization?`, which is
>>> still undesirable, but at least it doesn't result in data loss anymore.
>>>
>>> This fixes https://github.com/git-for-windows/git/issues/6346
>>>
>>> Signed-off-by: René Scharfe <l.s.r@web.de>
>>> ---
>>> How about this while we're waiting for a reroll?  It implements what the
>>> commit message says, nothing more.  Follows the style of the first loop.
>> 
>> This one I think is obvious and clear.  Why not take the authorship
>> too so that we do not have to worry about DCO?
>
> That feels unfair: Matthias did most of the work by identifying the bug
> and removing the premature subtraction from the loop doesn't seem very
> original to me.  Ultimately my main concern is getting this surprisingly
> impactful bug fixed in a reasonable amount of time, though..
>
> René

If we can get Matthias sign this patch off, that would work for me,
too.