From: Steven Rostedt <rostedt@goodmis.org>
To: Mykyta Yatsenko <mykyta.yatsenko5@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, mhiramat@kernel.org, andrii@kernel.org,
kernel-team@meta.com, linux-kernel@vger.kernel.org,
Mykyta Yatsenko <yatsenko@meta.com>,
Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH v2] maccess: fix strncpy_from_user_nofault empty string handling
Date: Wed, 23 Apr 2025 09:59:41 -0400 [thread overview]
Message-ID: <20250423095941.1cab813f@gandalf.local.home> (raw)
In-Reply-To: <08e3ec4c-4401-403e-9d81-5ee0abebba5c@gmail.com>
On Wed, 23 Apr 2025 12:37:46 +0100
Mykyta Yatsenko <mykyta.yatsenko5@gmail.com> wrote:
> > Does this fix any known runtime issue? If so, please fully describe this?
> Not that I'm aware of. The issue could be found when trying to copy empty
> user space string in BPF program (and relying on return value).There are
> some usage of
> `strncpy_from_user_nofault` in tracing subsystem, but I'm not sure how to
> hit those code paths.
> >
Although your patch found a bug in the tracing subsystem, this wasn't the
cause. It only cared if the read faulted or not. It was incorrectly
checking for zero as non fault when in reality, it needed to check >= 0.
With that fixed, it should work the same with or without this patch.
-- Steve
next prev parent reply other threads:[~2025-04-23 13:57 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-22 13:14 Mykyta Yatsenko
2025-04-22 15:48 ` Andrii Nakryiko
2025-04-23 0:20 ` Andrew Morton
2025-04-23 11:37 ` Mykyta Yatsenko
2025-04-23 13:59 ` Steven Rostedt [this message]
2025-04-23 14:48 ` Mykyta Yatsenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250423095941.1cab813f@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=andrii@kernel.org \
--cc=keescook@chromium.org \
--cc=kernel-team@meta.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhiramat@kernel.org \
--cc=mykyta.yatsenko5@gmail.com \
--cc=yatsenko@meta.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox