From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8F6C5CD5BB1 for ; Tue, 26 May 2026 16:30:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 98C596B0088; Tue, 26 May 2026 12:30:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 93D2A6B0093; Tue, 26 May 2026 12:30:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8528C6B0095; Tue, 26 May 2026 12:30:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 705AE6B0088 for ; Tue, 26 May 2026 12:30:41 -0400 (EDT) Received: from smtpin24.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 2BDA1A03C5 for ; 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b=y/XeE+dnRy1Xi0o9tnQ5AgSctJJtMyK39nGJhTPIwGKfdvXa9TrQNPJLKY/jWbaTDHasB0 uLfLN9EUzlT7jdvRhrIboPiU50bMMsaDt1Od7tVuy0hHhWPLe12hp6+RJ0HBgFYOgX2P38 zRCvAkPN+JHKuVy0owStbN8ADa3+xu8= Received: from omf05.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id C20E31C033A; Tue, 26 May 2026 16:30:35 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf05.hostedemail.com (Postfix) with ESMTPA id 5CC3320010; Tue, 26 May 2026 16:30:31 +0000 (UTC) Date: Tue, 26 May 2026 12:31:03 -0400 From: Steven Rostedt To: David Laight Cc: =?UTF-8?B?QW5kcsOp?= Almeida , Peter Zijlstra , Juri Lelli , Vincent Guittot , Christian Brauner , Kees Cook , Shuah Khan , willy@infradead.org, mathieu.desnoyers@efficios.com, Linus Torvalds , akpm@linux-foundation.org, Yafang Shao , andrii.nakryiko@gmail.com, arnaldo.melo@gmail.com, Petr Mladek , linux-kernel@vger.kernel.org, kernel-dev@igalia.com, linux-mm@kvack.org, linux-api@vger.kernel.org, Bhupesh Subject: Re: [PATCH v2 4/6] sched: Extend task command name to 64 bytes Message-ID: <20260526123103.4facbaed@gandalf.local.home> In-Reply-To: <20260525114241.4b6f3050@pumpkin> References: <20260524-tonyk-long_name-v2-0-332f6bd041c4@igalia.com> <20260524-tonyk-long_name-v2-4-332f6bd041c4@igalia.com> <20260525114107.7fa5b4c1@pumpkin> <20260525114241.4b6f3050@pumpkin> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+SfqA0tIqUxOUmzDMPGsY2Bynwi9HM1FA= X-HE-Meta: U2FsdGVkX19+DgaPTwc4z7iRVXUSZOqrVEfAtGYSvV7OnTDacZ1Hw/MUPKcmm575Hv6x6ldX6k779vnxNpGWZI83exoqPnaDvD3uiHdZGrm7O5Kn8tyfMud8UFNzBiy7OmfhPALhmcYjVcad5UeM/aK2bFkxfct7yhyONa0bUJwJQYnXpiEhTGrDK4+ottHoOwIGmxDD9djJ4vguO4i/d9n6iTmTLNIPSiyaJZcjqepQIJDHLt8k5S3jRqxtjKvWU+LHRBTYm/VmDYxSfyjZj3V/j8+bRbPwmMHzhEo8tM5IGa6nnWPigAFfptTCc/yad9e10ugVvl7w7SVjyWGNoeMVvvQ9cdK+ X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 41FFF160014 X-Stat-Signature: e9zwjq4hs9mt6bbxt8t9g3cmi9ag6k5g X-HE-Tag-Orig: 1779813031-406674 X-HE-Tag: 1779813039-70524 X-HE-Meta: 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 SRAIAYrX 2rRvx6TthnAPRG3IQyR93eERysQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, 25 May 2026 11:42:41 +0100 David Laight wrote: > > > error = security_task_prctl(option, arg2, arg3, arg4, arg5); > > > @@ -2601,16 +2601,16 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, > > > error = -EINVAL; > > > break; > > > case PR_SET_NAME: > > > - comm[sizeof(me->comm) - 1] = 0; > > > + comm[TASK_COMM_LEN - 1] = 0; > > > if (strncpy_from_user(comm, (char __user *)arg2, > > > - sizeof(me->comm) - 1) < 0) > > > + TASK_COMM_LEN - 1) < 0) > > > > Nak - you can't do that. > > You are reading data that the application doesn't expect you to read. > > Or have I got confused over the names... You may have gotten confused by names, as sizeof(me->comm) is the same as TASK_COMM_LEN. Basically, the above doesn't change anything. -- Steve