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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C34A5CD4F52 for ; Tue, 19 May 2026 08:37:06 +0000 (UTC) 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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UtXi7ksR6za75HHkRrUPh2YRUWd5B3kE8GkjiT7ewOQ=; b=KtCYHWtJRMNR3PSjQ8q0HLBUvt E4Ppy+heJ+yZGUFIzPSDFKNGXtGwSyOad/10qNUKSMWMZTdTchEALOKcH6B/4aFX/gt3J+3McRSF3 sze70LGybjwQcC7SV/10MUyuFxsuALMBamFm5yDLwJvNvcFCcdh8IIQHxZvM6q3JxPjvq2FFwFrHx kQiyk5q3LDf2hTlF8G7SZ+lk7cTrLL2k68FYj8VYbmkV7AkLJjOYK/PLlcJxxxHQ29+uKhJs+ZukH sq/i6XGbauS+tXCaPqOarBvpZ6HQCEPbPtiSYTG9wwG0oNi0NkpoQds5n3XhvW1zt2b6gGf1ycoUb 0/g185Aw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wPFwi-00000000hNj-1qwH; Tue, 19 May 2026 08:37:00 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wPFwf-00000000hMw-2ctf for linux-arm-kernel@lists.infradead.org; Tue, 19 May 2026 08:36:59 +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 3A5C01E5E; Tue, 19 May 2026 01:36:49 -0700 (PDT) Received: from pluto (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 035AE3F85F; Tue, 19 May 2026 01:36:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1779179814; bh=cURbMm2okKUDguBxbYSJRZ9JHQhDdBDG/WbOFz3bvQg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=J49n4wDk9qpghf5622OsChKbMNxP1ppkvk6334034/IMUHveTqtL2Opa/uFTArrvU eh0vDsoxhOPUMW2SMJsfSsuAFyWegJTU0XKRFGWFjxQVOZC8lWGfbG5ifguzIADOHA WMEo+fOedq3HwzCMyRp3aWSj8+SASHbZuXnKDzg0= Date: Tue, 19 May 2026 09:36:40 +0100 From: Cristian Marussi To: Geert Uytterhoeven Cc: Cristian Marussi , Dan Carpenter , Sudeep Holla , arm-scmi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] firmware: arm_scmi: Fix OOB in scmi_power_name_get() Message-ID: References: <75caae28bdffb55199a0bc6cac5df112a966c608.1778838987.git.geert+renesas@glider.be> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260519_013658_053047_703B4BD3 X-CRM114-Status: GOOD ( 29.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, May 15, 2026 at 01:10:56PM +0100, Cristian Marussi wrote: > On Fri, May 15, 2026 at 02:00:24PM +0200, Geert Uytterhoeven wrote: > > Hi Cristian, > > > > On Fri, 15 May 2026 at 13:46, Cristian Marussi wrote: > > > On Fri, May 15, 2026 at 01:29:27PM +0200, Geert Uytterhoeven wrote: > > > > On Fri, 15 May 2026 at 12:28, Dan Carpenter wrote: > > > > > On Fri, May 15, 2026 at 11:59:15AM +0200, Geert Uytterhoeven wrote: > > > > > > scmi_power_name_get() does not validate the domain number passed by the > > > > > > external caller, which may lead to an out-of-bounds access. > > > > > > > > > > Is an external caller an out of tree caller? So far as I can see this > > > > > > > > I meant a caller outside drivers/firmware/arm_scmi/. > > > > > > > > > is only called by scmi_pm_domain_probe(). > > > > > > > > > > scmi_pd->name = power_ops->name_get(ph, i); > > > > > > > > > > where i < num_domains. > > > > > > > > You are right. But this seems to be only API implementation in > > > > drivers/firmware/arm_scmi/ that does not validate the passed domain > > > > number. > > > > > > Yes we tend to validate protocol operations calls even if apparently > > > safe from teh caller perspective...indeed I have this fixed locally > > > since ages in an horrible patch, that does a lot more, and that I > > > never posted :P > > > > > > Usually, if it is worth, we also build an internal domain get helper to > > > reuse across the protocol unit...but here really there are only 2 call-sites. > > > > > > What I am not sure is what to return: "unknown" is safer as of now than NULL > > > for sure, but really, what happened is NOT that the name was "unknown" (which > > > by itself would be out-of-spec behaviour) it is more that the whole domain that > > > was referred to that was invalid and NOT existent... > > > > > > ....mmm I suppose we are opening another can of worms here :P > > > > Like scmi_perf_info_get() returning ERR_PTR(-EINVAL) instead of NULL, > > and scmi_perf_domain_probe() never checking the return value anyway? > > ...oh probably more than that...and related vendor FW that already exploits > these missing checks here and there to arbitrarily skip domains and return > out-of-spec non-contigous sets of domains becasue they cannot bother to > implement properly the spec (or they have simply forked their codebase from > an old drop and never updated it again...)...so that any kernel-side fix > you made along the road carries the risk of breaking something and a string > of possibly needed quirks... Anyway, it is the safest option on the table until proper checks are in place. Reviewed-by: Cristian Marussi Thanks, Cristian