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 2F00FC36014 for ; Tue, 1 Apr 2025 10:02:48 +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:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-ID:Date:From:Cc:To:Subject:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=3OeugnkYPiAsBbjBUAR2ctq6ULvFAMrOKKtUxMndoTk=; b=3FCKApU05pZNaXhpAjhH83SNPw tKP02QRtGbJ/aE0fN61i4TMr3wrZzTgqf9I99vRAVhTk9vlhnFXJgXsoPa4RJj+zIP3R0l4zzCWoG m4FHaKJP/ePohkGEtdMZBi8sTQvhes130Nd1GXIXbPS1oJp70yc9OaEF5wY/tKsgOUTBWjcQj+3VM c1qSbJD2CtwHvR8Lq/msMME3c1U1fIUzxBJWED1FmGOtlV0V3Bd/3sCC+o2FSkRQVSNV1wL5YSIsO Gek88czdX1t6m3cAJ0B/PMpLsM9RggJzJWTWJnIXXpWPJSjvPkFuv2+7Mn4xXolOfVylLC6Wy3dLZ NMBQJDCA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzYS1-00000002YYG-3Ven; Tue, 01 Apr 2025 10:02:33 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzXoG-00000002SkR-3wLz for linux-arm-kernel@lists.infradead.org; Tue, 01 Apr 2025 09:21:30 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 37AB8440BB; Tue, 1 Apr 2025 09:21:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36782C4CEE5; Tue, 1 Apr 2025 09:21:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1743499288; bh=LPK6HFgVt6ngS+5xgXU6waSrwkWSjM+aSlWeOcrzuUg=; h=Subject:To:Cc:From:Date:From; b=Zzjxy1fW4xOR+GyUUEIUj2gJTeGkhi7EYzxN4jaIWpH9udGL6CP3Zaa9/lmw/ALV7 tnhAGjjBwjopmhp48sEGC+gbOkq+3Iy+ZFRLcmXp+RJVQIFEnC4VMwcaPSnLPSviDo cFKkcxTNlbkpJEJcnsqa/bV8gf+aN4ZUhSY6h7po= Subject: Patch "ARM: 9350/1: fault: Implement copy_from_kernel_nofault_allowed()" has been added to the 6.6-stable tree To: akpm@linux-foundation.org,ardb@kernel.org,ben@decadent.org.uk,broonie@kernel.org,gregkh@linuxfoundation.org,keescook@chromium.org,linux-arm-kernel@lists.infradead.org,rmk+kernel@armlinux.org.uk,wangkefeng.wang@huawei.com Cc: From: Date: Tue, 01 Apr 2025 10:19:51 +0100 Message-ID: <2025040151-unwashed-antiquity-85a1@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250401_022129_156950_B1031AF4 X-CRM114-Status: GOOD ( 13.43 ) 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 This is a note to let you know that I've just added the patch titled ARM: 9350/1: fault: Implement copy_from_kernel_nofault_allowed() to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm-9350-1-fault-implement-copy_from_kernel_nofault_allowed.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From 169f9102f9198b04afffa6164372a4ba4070f412 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 1 Feb 2024 18:32:58 +0100 Subject: ARM: 9350/1: fault: Implement copy_from_kernel_nofault_allowed() From: Kees Cook commit 169f9102f9198b04afffa6164372a4ba4070f412 upstream. Under PAN emulation when dumping backtraces from things like the LKDTM EXEC_USERSPACE test[1], a double fault (which would hang a CPU) would happen because of dump_instr() attempting to read a userspace address. Make sure copy_from_kernel_nofault() does not attempt this any more. Closes: https://lava.sirena.org.uk/scheduler/job/497571 Link: https://lore.kernel.org/all/202401181125.D48DCB4C@keescook/ [1] Reported-by: Mark Brown Suggested-by: Russell King (Oracle) Reviewed-by: Ard Biesheuvel Tested-by: Mark Brown Cc: Wang Kefeng Cc: Andrew Morton Cc: Ben Hutchings Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kees Cook Signed-off-by: Russell King (Oracle) Signed-off-by: Greg Kroah-Hartman --- arch/arm/mm/fault.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -25,6 +25,13 @@ #include "fault.h" +bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size) +{ + unsigned long addr = (unsigned long)unsafe_src; + + return addr >= TASK_SIZE && ULONG_MAX - addr >= size; +} + #ifdef CONFIG_MMU /* Patches currently in stable-queue which might be from keescook@chromium.org are queue-6.6/arm-9350-1-fault-implement-copy_from_kernel_nofault_allowed.patch queue-6.6/arm-9351-1-fault-add-cut-here-line-for-prefetch-aborts.patch