From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793016986; b=evg/hGx5gqjudKDjCZidFZ/sQht6NnpJfLlWU2iIYcwoep/pdVgKaAzLs1MJuO+CxYHM iWeykhh99ybibPO7sRRl4MaIhI5BvzyNafRKz0itBsHrdKfHp7w/TZazEyZjbhtIHP9fL BrULNXBES0e8mFGG2UTaZyN0gfDyaQXUsJqiAkn2W/q5t4q897K38l3B5QBsrzrUwDehV zMDkk3KkcU+pKgMNetbqA6o78BTEPqWkB8bdotDVyNLxoKYiClZzvl40mPXY1CL6iGyRB t96Z5u2JY20W5nOYkUHwMVK23FH7hQPjziTpNt0mnK43Ivn848sztZmH3mPCRa0M5tQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793016986; h=DMARC-Filter:Received:Received:DKIM-Signature:Message-ID:Date: MIME-Version:User-Agent:Subject:To:Cc:References:Content-Language: From:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=Rg0ETYbEaunw+LkMJf50lkBOkvciZg3rbVHhzrZnfXw=; b=OlIQRM5vOLWODaQAoQWx6wg7dh3hTa5W18z9AzjWgkXzJfHtFkrkRuMoaMOJWTnAQ93O LrZsZobKLC4f/GpQKnJebOUABezLN8UfU5/62hfpb6qrsQSNMJquFaQBKPTLOndF8LZK1 4KWSMeX1fWe0kSESQov9GyEeN0mrzVWfGQjnl0fNbyImqfZDhmI2xsvGWMR4Kelce901M VLy0bibEoFPjbHKLFVrvvUXs+PCxFXRJdsrB3bCq3//LyZjEAQTcgdsQbTk8Nqbe3xuM7 2bzx/rtFTAPpK/FUt6uLebLDmUuzzaIO9MborQyQW03N3tMNoRuxg5f4mn95iFfmJTQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=h5Zoek30; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 46A27606A322 for ; Mon, 26 Oct 2026 12:16:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 46A27606A322 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=h5Zoek30 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6EC1215A1; Mon, 26 Oct 2026 05:16:22 -0700 (PDT) Received: from [10.2.212.8] (e134344.arm.com [10.2.212.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CF8593F7B4; Mon, 26 Oct 2026 05:16:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793016985; bh=Gk4eUsoyed4B957tUYZATCS0kUgqsVIGWKLqcaoh44U=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=h5Zoek30G0L+Q7LsMI3bb6Z9oGY3tyyoKd09cgYLswpa0ALiG2swjoNgL8wLguwgl 7/ZeVD+zOKKceSTAYzcRIqvFHgp0kaRz5ICw+2wwpSOZHeGuVYAfovsNExLNL8vFFs Fq/PWI1Wgg+FZId5F0j7Rg822id+Doa49D3Cmlo4= Message-ID: Date: Mon, 26 Oct 2026 12:16:23 +0000 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] arm_mpam: Reject ris_idx == MPAM_MSC_MAX_NUM_RIS To: Ping Li , james.morse@arm.com Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, reinette.chatre@intel.com, fenghuay@nvidia.com References: <20261022085710.1597276-1-leeonion.muyu@gmail.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <20261022085710.1597276-1-leeonion.muyu@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Ping, On 22/10/2026 09:57, Ping Li wrote: > While checking the driver's partid and ris bound checks, after the > hardware team mistakenly configured PARTID_MAX in an MSC to 16, > this issue was found: MPAM_MSC_MAX_NUM_RIS is the max number of > RIS an MSC can have, so a ris_idx of 16 passes the current check, > and would later be silently truncated to 0 by FIELD_PREP(), > landing all configuration for that ris on RIS 0. > > Signed-off-by: Ping Li Thanks for the patch. Yin already found the same bug and posted a fix first so I'll go with that one. https://lore.kernel.org/linux-arm-kernel/20261008-mpam-resctrl-dt-knp-support-v3-1-35196c2b43bf@oss.qualcomm.com/ Thanks, Ben > --- > drivers/resctrl/mpam_devices.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c > index 48adc49b833c..347a5a6d6a1d 100644 > --- a/drivers/resctrl/mpam_devices.c > +++ b/drivers/resctrl/mpam_devices.c > @@ -700,7 +700,7 @@ static int mpam_ris_create_locked(struct mpam_msc *msc, u8 ris_idx, > > lockdep_assert_held(&mpam_list_lock); > > - if (ris_idx > MPAM_MSC_MAX_NUM_RIS) > + if (ris_idx >= MPAM_MSC_MAX_NUM_RIS) > return -EINVAL; > > if (test_and_set_bit(ris_idx, &msc->ris_idxs))