From: Kees Cook <kees@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Bhupesh <bhupesh@igalia.com>,
akpm@linux-foundation.org, kernel-dev@igalia.com,
linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
linux-perf-users@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, oliver.sang@intel.com, lkp@intel.com,
laoar.shao@gmail.com, pmladek@suse.com, rostedt@goodmis.org,
mathieu.desnoyers@efficios.com, arnaldo.melo@gmail.com,
alexei.starovoitov@gmail.com, andrii.nakryiko@gmail.com,
mirq-linux@rere.qmqm.pl, peterz@infradead.org,
willy@infradead.org, david@redhat.com, viro@zeniv.linux.org.uk,
ebiederm@xmission.com, brauner@kernel.org, jack@suse.cz,
mingo@redhat.com, juri.lelli@redhat.com, bsegall@google.com,
mgorman@suse.de, vschneid@redhat.com,
linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH v6 2/3] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation
Date: Sat, 26 Jul 2025 16:19:18 -0700 [thread overview]
Message-ID: <B9C50D0B-DCD9-41A2-895D-4899728AF605@kernel.org> (raw)
In-Reply-To: <CAHk-=wi5c=_-FBGo_88CowJd_F-Gi6Ud9d=TALm65ReN7YjrMw@mail.gmail.com>
On July 26, 2025 10:50:55 AM PDT, Linus Torvalds <torvalds@linux-foundation.org> wrote:
>, but
>
>On Thu, 24 Jul 2025 at 16:49, Kees Cook <kees@kernel.org> wrote:
>>
>> Why not switch all of these to get_task_comm()? It will correctly handle
>> the size check and NUL termination.
>
>I'd rather aim to get rid of get_task_comm() entirely.
That works for me! I just get twitchy around seeing memcpy used for strings. :) if we're gonna NUL after the memcpy, just use strscpy_pad().
>And guess what? We *have* that function. It's called "strscpy()". It
>already does the right thing, including passing in the size of a fixed
>array and just dealing with it the RightWay(tm). Add '_pad()' if that
>is the behavior you want, and now you *document* the fact that the
>result is padded.
Exactly. Let's see how much we can just replace with strscpy_pad(). It we have other use cases, we can handle those separately.
-Kees
--
Kees Cook
next prev parent reply other threads:[~2025-07-26 23:19 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-24 12:36 [PATCH v6 0/3] Add support for long task name Bhupesh
2025-07-24 12:36 ` [PATCH v6 1/3] exec: Remove obsolete comments Bhupesh
2025-07-24 23:50 ` Kees Cook
2025-07-24 12:36 ` [PATCH v6 2/3] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation Bhupesh
2025-07-24 23:49 ` Kees Cook
2025-07-26 17:50 ` Linus Torvalds
2025-07-26 23:19 ` Kees Cook [this message]
2025-07-26 23:37 ` Linus Torvalds
2025-08-05 11:13 ` Bhupesh Sharma
2025-07-24 12:36 ` [PATCH v6 3/3] include: Set tsk->comm length to 64 bytes Bhupesh
2025-07-24 23:38 ` Kees Cook
2025-07-26 11:20 ` kernel test robot
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