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 E5FA6C369A4 for ; Tue, 8 Apr 2025 13:14:27 +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: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=FrcUYapzyROm87ztaGIkE8QfzaqTAT8f2yheX+hCtpA=; b=IZeQQhWp8PZ+l+YRUs6/iDOqX5 TABUvKHBZ2EV8OQHWqzEkEz7zfZxk0KtxW3EqkYI695qobxwDantrK+oGki/P53xKN7YVwM8bCYh+ RXXOVSZi9eL99Mo1h9QQnEIpe8cooTN2tHpeu/TDTpsBQen6a6SzyXRKSoo4bC50T4CwX1JJwmWOY tnWx9t9FVWkQhIcnm/cKl7Axt6qCN9p1pwGTb552XCjpyY6gCG/mzvPYqe7fMk+4hBzkyubed9vFS MVNOnEm+nZQy8u57p0XP63QXUFKEaLZlY7mD80BWbR+m+IDQfONpdfmdsdZ7Fo2YXnluTN+8b5ZMi GlqZXS9Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1u28mP-0000000477h-40Ug; Tue, 08 Apr 2025 13:14:17 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1u27Lo-00000003snC-1sFu for linux-arm-kernel@lists.infradead.org; Tue, 08 Apr 2025 11:42:45 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 46CE55C1194; Tue, 8 Apr 2025 11:40:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A61F9C4CEE5; Tue, 8 Apr 2025 11:42:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744112562; bh=E3kJhKCYWfHqXreF27z87MG0nJUDiKKvzCqnE/3WopE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cDM4TwEFf8NKAWAYYxJEw4CKnMmaFKxxrarUTGdk6RxlxE31IGmv2pqqngTk4PhT/ tbzHkesUjdrK5pMnvbiXaue2hLGJ3RszSOAPvVDRn/GiJWeyJDW3dg/dQTLwCQtqJT D+LDP8St0HYXO3FbU8go5x2zSJV9QxkxiRRIXkDU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mark Brown , "Russell King (Oracle)" , Ard Biesheuvel , Wang Kefeng , Andrew Morton , Ben Hutchings , linux-arm-kernel@lists.infradead.org, Kees Cook Subject: [PATCH 5.15 113/279] ARM: 9350/1: fault: Implement copy_from_kernel_nofault_allowed() Date: Tue, 8 Apr 2025 12:48:16 +0200 Message-ID: <20250408104829.397723163@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250408104826.319283234@linuxfoundation.org> References: <20250408104826.319283234@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250408_044244_540389_52914921 X-CRM114-Status: GOOD ( 10.76 ) 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ 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 @@ -24,6 +24,13 @@ #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 /*