From: Linus Torvalds <torvalds@linux-foundation.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Yafang Shao <laoar.shao@gmail.com>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org, audit@vger.kernel.org,
linux-security-module@vger.kernel.org, selinux@vger.kernel.org,
bpf@vger.kernel.org, Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: Re: [PATCH 2/6] tracing: Replace memcpy() with __get_task_comm()
Date: Mon, 3 Jun 2024 14:42:10 -0700 [thread overview]
Message-ID: <CAHk-=whPUBbug2PACOzYXFbaHhA6igWgmBzpr5tOQYzMZinRnA@mail.gmail.com> (raw)
In-Reply-To: <20240603172008.19ba98ff@gandalf.local.home>
On Mon, 3 Jun 2024 at 14:19, Steven Rostedt <rostedt@goodmis.org> wrote:
>
> - __array( char, comm, TASK_COMM_LEN )
> + __string( comm, strlen(comm) )
Is this actually safe is 'comm[]' is being modified at the same time?
The 'strlen()' will not be consistent with the string copy.
Because that is very much the case. It's not a stable source.
For example, strlen() may return 5. But by the time you then actually
copy the data, the string may have changed, and there would not
necessarily be a NUL character at comm[5] any more. It might be
further in the string, or it might be earlier.
Linus
next prev parent reply other threads:[~2024-06-03 21:42 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-02 2:37 [PATCH 0/6] kernel: Avoid memcpy of task comm Yafang Shao
2024-06-02 2:37 ` [PATCH 1/6] fs/exec: Drop task_lock() inside __get_task_comm() Yafang Shao
2024-06-02 3:51 ` Eric W. Biederman
2024-06-02 6:56 ` Yafang Shao
2024-06-02 16:35 ` Alexei Starovoitov
2024-06-02 17:52 ` Eric W. Biederman
2024-06-02 18:23 ` Alexei Starovoitov
2024-06-03 11:35 ` Yafang Shao
2024-06-10 12:34 ` Eric W. Biederman
2024-06-10 23:01 ` Alexei Starovoitov
2024-06-02 17:56 ` Eric W. Biederman
2024-06-04 13:02 ` Matus Jokay
2024-06-04 20:01 ` Matus Jokay
2024-06-05 2:48 ` Yafang Shao
2024-06-02 2:37 ` [PATCH 2/6] tracing: Replace memcpy() with __get_task_comm() Yafang Shao
2024-06-03 21:20 ` Steven Rostedt
2024-06-03 21:42 ` Linus Torvalds [this message]
2024-06-03 22:19 ` Steven Rostedt
2024-06-03 22:23 ` Linus Torvalds
2024-06-03 22:37 ` Steven Rostedt
2024-06-03 22:38 ` Linus Torvalds
2024-06-03 22:40 ` Steven Rostedt
2024-06-04 2:35 ` Yafang Shao
2024-06-02 2:37 ` [PATCH 3/6] auditsc: " Yafang Shao
2024-06-03 21:03 ` Paul Moore
2024-06-02 2:37 ` [PATCH 4/6] security: " Yafang Shao
2024-06-03 22:06 ` Paul Moore
2024-06-02 2:37 ` [PATCH 5/6] bpftool: Make task comm always be NUL-terminated Yafang Shao
2024-06-02 21:01 ` Quentin Monnet
2024-06-02 2:46 ` [PATCH 6/6] selftests/bpf: Replace memcpy() with __get_task_comm() Yafang Shao
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