From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EC8CB606A31E for ; Mon, 26 Oct 2026 12:17:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=AA7f2UKj; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=h5Zoek30 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=Rg0ETYbEaunw+LkMJf50lkBOkvciZg3rbVHhzrZnfXw=; b=AA7f2UKjNh2ILC /GZPagxMfYjl8eGqTE6eY2VBh+uKlehWkRhR3q/2nm8aBh+rvzrUU6GC5+caGxh6kjKr5azymm6X5 cpVXV4O5IoZmj99zEYrYpbAC6jI4wbsz9uT1cFtlry9p4v/UhlwotOyh67q4oahHBmw7fDpKEqt1P CfF9thjeqo/9zIdgAPCmWj9T+DCNC4jdpi4CoHk0QnPTPRiWirT0MFJ2yeNUIOoTYTDccYPwDd5fv 1MM0I1JdPVAVcxjUkFdFSs30TZY9K5nD3h9tK8CBmLXaDFDslWZyTVA9GY+oz0Gpj6ntOpyIF+Byv pHUwtQ9eGcsSPSpuDx3A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLJcs-00000002UGg-1U90; Mon, 26 Oct 2026 12:16:30 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLJcq-00000002UGG-0Ii1 for linux-arm-kernel@lists.infradead.org; Mon, 26 Oct 2026 12:16:29 +0000 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-Archived-By: 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261026_051628_164420_F2950037 X-CRM114-Status: GOOD ( 15.45 ) X-Spam-Score: -4.4 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 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))