From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B41203B38AB; Tue, 26 May 2026 16:30:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779813041; cv=none; b=iKuvNV+jFF4tPXfYqOnpMGDpTJ3Fd/A/tJm+Yg//JWT2Ba5BJ99fr58cS6L6Z5s3/12YO03NKSYrvJNx9ovLSqr4BpcnWjRyyR0skeRqc/n1T4Q/rb522G7ucBJ7VZMPDgg3kFcoAOThQgu0ocRx1hyvfLwo4l++NeM7DLoBLxQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779813041; c=relaxed/simple; bh=4RHUPrOhy8Rckt9kmEsawMj3CTJh4VdgYBT2gsMHQC8=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=aq1Lofxsn9KD65nuWXSShGIYxZH5Xrk2kbVpmE3KlzXMVu/FFTRzo/05qRdDHfMvgzEjwnT9tE4BIr0bAo68HeVn6FPo914OXR2nBiCZ7SlUUI77yuGlX9bam5nBpCu8fen4U4Ovtnztm182xiPTlzpsMyaZhU9RVCjU/nfzkJs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org 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) Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: 4oyjjqmuesmiumwmpy1rnjhsc49eyn1n X-Rspamd-Server: rspamout08 X-Rspamd-Queue-Id: 5CC3320010 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+SfqA0tIqUxOUmzDMPGsY2Bynwi9HM1FA= X-HE-Tag: 1779813031-406674 X-HE-Meta: U2FsdGVkX19+DgaPTwc4z7iRVXUSZOqrVEfAtGYSvV7OnTDacZ1Hw/MUPKcmm575Hv6x6ldX6k779vnxNpGWZI83exoqPnaDvD3uiHdZGrm7O5Kn8tyfMud8UFNzBiy7OmfhPALhmcYjVcad5UeM/aK2bFkxfct7yhyONa0bUJwJQYnXpiEhTGrDK4+ottHoOwIGmxDD9djJ4vguO4i/d9n6iTmTLNIPSiyaJZcjqepQIJDHLt8k5S3jRqxtjKvWU+LHRBTYm/VmDYxSfyjZj3V/j8+bRbPwmMHzhEo8tM5IGa6nnWPigAFfptTCc/yad9e10ugVvl7w7SVjyWGNoeMVvvQ9cdK+ 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