From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D79302A1B2; Wed, 26 Mar 2025 09:39:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742981965; cv=none; b=AgMN6tkUeDNb+Wa/BB98SDydO3UFD3yu2RTLd59wEF7tDhtv8lTHRFPkMDj2VkH2sIJRdyHxu5o6kf/tFaVH493Haih2J9ziej8EsNMHv1nX5RfmYXFU2V4f9633t3OFfFlcVyHvi3d438IyiQNngxXz+apiLFuNzFMik2/GMF8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742981965; c=relaxed/simple; bh=Mp7PS2Hsz1Y1++3pUe2iXl59mJgfLQOY3hRaKyxKOI4=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=QMSXGYDTxx6rNhPjh/CUHnFFlquS9fW60Ov1ALeOkqgyVp9H4xL48OEDYC/ZDM0RlqyayVdheWDX+b6VB2Zzo7l+bYEBJ/hh49BURfctiXDrk94uLE12QtohqGax1QgOs14fNCvok52dkUgOLWMxKuW1AodltV3UM4njRVxFIOc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ApaHC+Uf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ApaHC+Uf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58BCFC4CEEA; Wed, 26 Mar 2025 09:39:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742981965; bh=Mp7PS2Hsz1Y1++3pUe2iXl59mJgfLQOY3hRaKyxKOI4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ApaHC+Uf5A1ua9ePUD6nc+4eNxhxdmJH86reahFps3SZnbjkkcaDbtuuLG46Q2vwn 9p5C9lhcUgbVIhErca64F5Klq1j3vBjf3203GoyfTL/1Ro3RxORx4H5PUAFgz0CJXC wxcnse2vbdu3drRJT+Z0zstzCF+lYGNA9ZRRB9WCR7RMeTFQa0zpLwVoa5pGPS4v0O qDEgtHVffgkTlaXwitLFukstMZB7CmXrI4VU6YUTefSWl8J3+KbKaqMRbMeHp67iK6 D9VB2WjE1p5cAafC/2mhoTnozJlOzRP8luEoYrO4R4rHj9gFFHz8lVA3PTc1+23VCy 3TmocOn5qRnXw== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1txNEJ-00HEb9-0v; Wed, 26 Mar 2025 09:39:23 +0000 Date: Wed, 26 Mar 2025 09:39:22 +0000 Message-ID: <86zfh8ku5x.wl-maz@kernel.org> From: Marc Zyngier To: Keir Fraser Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Kristina Martsenko , Catalin Marinas , Mark Rutland , Will Deacon , stable@vger.kernel.org Subject: Re: [PATCH] arm64: mops: Do not dereference src reg for a set operation In-Reply-To: <20250326070255.2567981-1-keirf@google.com> References: <20250326070255.2567981-1-keirf@google.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: keirf@google.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kristina.martsenko@arm.com, catalin.marinas@arm.com, mark.rutland@arm.com, will@kernel.org, stable@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Wed, 26 Mar 2025 07:02:55 +0000, Keir Fraser wrote: > > The register is not defined and reading it can result in a UBSAN > out-of-bounds array access error, specifically when the srcreg field > value is 31. Gah, XZR/SP encoding strikes back... > > Cc: Kristina Martsenko > Cc: Catalin Marinas > Cc: Mark Rutland > Cc: Will Deacon > Cc: Marc Zyngier > Cc: stable@vger.kernel.org > Signed-off-by: Keir Fraser > --- > arch/arm64/include/asm/traps.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h > index d780d1bd2eac..82cf1f879c61 100644 > --- a/arch/arm64/include/asm/traps.h > +++ b/arch/arm64/include/asm/traps.h > @@ -109,10 +109,9 @@ static inline void arm64_mops_reset_regs(struct user_pt_regs *regs, unsigned lon > int dstreg = ESR_ELx_MOPS_ISS_DESTREG(esr); > int srcreg = ESR_ELx_MOPS_ISS_SRCREG(esr); > int sizereg = ESR_ELx_MOPS_ISS_SIZEREG(esr); > - unsigned long dst, src, size; > + unsigned long dst, size; > > dst = regs->regs[dstreg]; > - src = regs->regs[srcreg]; > size = regs->regs[sizereg]; > > /* > @@ -129,6 +128,7 @@ static inline void arm64_mops_reset_regs(struct user_pt_regs *regs, unsigned lon > } > } else { > /* CPY* instruction */ > + unsigned long src = regs->regs[srcreg]; > if (!(option_a ^ wrong_option)) { > /* Format is from Option B */ > if (regs->pstate & PSR_N_BIT) { Reviewed-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible.