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 9CBB82550D0; Thu, 29 May 2025 06:34:14 +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=1748500454; cv=none; b=NUCmJ4MTXJSXfjLeuODuIfVCgmDpJhyMWsKX+X7UG/Or42lbSPKDUr6ymZmKmnJ9leju1Me8DDUiAOl4Q5aoc5mywEZQX7Ere0a2c2fBa/NJeX9URJnrTusmTkeCeM/bd7gO+Wo/khzuOm/+2aJemX7fETD+sHiWtVjHBhAt7q4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748500454; c=relaxed/simple; bh=jPXnV/GmrjuvGJ+yT7bOTWgocTVuwOXAwKsmzosSDgI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IBW9e2m8/ZeK4f10BPPvR+71aN7igS52aaglKF7Hl/eWTvtjZNxMvCH7DP6b1oZuBzX30sNYSaLYfM1FTnQdCYFryBxmdvtzRTEs5+7nhwtfT+FrVz4mJDnqyHuXvdZeD9HVUHCKdd9vm8o6uniLy+dYSTM0/4YhM56vgGhGSV8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ygbW36zM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ygbW36zM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B35EC4CEEA; Thu, 29 May 2025 06:34:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748500454; bh=jPXnV/GmrjuvGJ+yT7bOTWgocTVuwOXAwKsmzosSDgI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ygbW36zMZzJvQHb4nesmpWDtGVwsayeKkusn4zQXt9mXfHYoOuDhVQ660kKAhAloX RVMY+n/hM6AwWyMUS3hM9PjNw6q/gTwtUMZUnlfgcnxLJLl+TIr9fLO0AUWz0qQXcf kXt6rnxFXD6c5RRISw7ze8Cdmif7y1TdF/8OboI0= Date: Thu, 29 May 2025 08:34:10 +0200 From: Greg Kroah-Hartman To: Brian Gerst Cc: stable@vger.kernel.org, patches@lists.linux.dev, Ingo Molnar , Ard Biesheuvel , Linus Torvalds , Sasha Levin Subject: Re: [PATCH 6.14 426/783] x86/boot: Disable stack protector for early boot code Message-ID: <2025052945-squabble-romp-6304@gregkh> References: <20250527162513.035720581@linuxfoundation.org> <20250527162530.470565771@linuxfoundation.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Wed, May 28, 2025 at 01:52:16PM -0400, Brian Gerst wrote: > On Tue, May 27, 2025 at 1:39 PM Greg Kroah-Hartman > wrote: > > > > 6.14-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Brian Gerst > > > > [ Upstream commit a9a76b38aaf577887103e3ebb41d70e6aa5a4b19 ] > > > > On 64-bit, this will prevent crashes when the canary access is changed > > from %gs:40 to %gs:__stack_chk_guard(%rip). RIP-relative addresses from > > the identity-mapped early boot code will target the wrong address with > > zero-based percpu. KASLR could then shift that address to an unmapped > > page causing a crash on boot. > > > > This early boot code runs well before user-space is active and does not > > need stack protector enabled. > > > > Signed-off-by: Brian Gerst > > Signed-off-by: Ingo Molnar > > Reviewed-by: Ard Biesheuvel > > Cc: Linus Torvalds > > Link: https://lore.kernel.org/r/20250123190747.745588-4-brgerst@gmail.com > > Signed-off-by: Sasha Levin > > --- > > arch/x86/kernel/Makefile | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile > > index b43eb7e384eba..84cfa179802c3 100644 > > --- a/arch/x86/kernel/Makefile > > +++ b/arch/x86/kernel/Makefile > > @@ -44,6 +44,8 @@ KCOV_INSTRUMENT_unwind_orc.o := n > > KCOV_INSTRUMENT_unwind_frame.o := n > > KCOV_INSTRUMENT_unwind_guess.o := n > > > > +CFLAGS_head32.o := -fno-stack-protector > > +CFLAGS_head64.o := -fno-stack-protector > > CFLAGS_irq.o := -I $(src)/../include/asm/trace > > > > obj-y += head_$(BITS).o > > -- > > 2.39.5 > > > > > > > > This doesn't need to be backported. It's harmless, but not necessary > without the rest of the stack protector changes. What specific changes? I see stackprotector code in this, and the 6.12 tree, so what commit id does this "fix"? thanks, greg k-h