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 X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98AE6C282C4 for ; Wed, 13 Feb 2019 03:02:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 656442190A for ; Wed, 13 Feb 2019 03:02:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550026971; bh=tH8LjbMMFIDZaNfYmh2W5NDshAm5TaldNQK6TDiTycE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=C5gsSP9jS3/b/SW08DSenNMhCIGf9j1U5no4Fah/49FFmvNMZzxhMg+IcKpMa8dME RaXY1U10PAH4XwiN5NWNkM880b3gmhdKECXrXZxJDbBssi86EN08fV0gNueSP47v8z mgsWk5RrfEbS+PKXrqkqPbnKuUYltt1FelhjJ1Ek= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390373AbfBMDCu (ORCPT ); Tue, 12 Feb 2019 22:02:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:38402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387819AbfBMCet (ORCPT ); Tue, 12 Feb 2019 21:34:49 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C3D0B222CA; Wed, 13 Feb 2019 02:34:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550025288; bh=tH8LjbMMFIDZaNfYmh2W5NDshAm5TaldNQK6TDiTycE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Tjt5K6gtLHpegPTw5zZa+9gOING60wpeeldBog+nei3gwiBzutnBoRyb5T7R+5u8H DfHaXds//hsIrCchEY4mdcNFPp10c3Ragb9TIF7MT15HaAiCSBOHW5tgx5TWvWK/NM aCsdIarvE/8b6LenwFKk+K0vpavctgFcxllKT4sY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Song Liu , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.20 047/105] bpf: fix panic in stack_map_get_build_id() on i386 and arm32 Date: Tue, 12 Feb 2019 21:32:38 -0500 Message-Id: <20190213023336.19019-47-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190213023336.19019-1-sashal@kernel.org> References: <20190213023336.19019-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Song Liu [ Upstream commit beaf3d1901f4ea46fbd5c9d857227d99751de469 ] As Naresh reported, test_stacktrace_build_id() causes panic on i386 and arm32 systems. This is caused by page_address() returns NULL in certain cases. This patch fixes this error by using kmap_atomic/kunmap_atomic instead of page_address. Fixes: 615755a77b24 (" bpf: extend stackmap to save binary_build_id+offset instead of address") Reported-by: Naresh Kamboju Signed-off-by: Song Liu Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- kernel/bpf/stackmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 90daf285de03..d9e2483669d0 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -260,7 +260,7 @@ static int stack_map_get_build_id(struct vm_area_struct *vma, return -EFAULT; /* page not mapped */ ret = -EINVAL; - page_addr = page_address(page); + page_addr = kmap_atomic(page); ehdr = (Elf32_Ehdr *)page_addr; /* compare magic x7f "ELF" */ @@ -276,6 +276,7 @@ static int stack_map_get_build_id(struct vm_area_struct *vma, else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64) ret = stack_map_get_build_id_64(page_addr, build_id); out: + kunmap_atomic(page_addr); put_page(page); return ret; } -- 2.19.1