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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 5A9ADC282C4 for ; Wed, 13 Feb 2019 02:53:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24FEF21934 for ; Wed, 13 Feb 2019 02:53:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550026422; bh=TNkmIcypAoyoP3+FNg/zLJ4g6tuh4egK7HK+8TMCHKo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SxlHZU7viZ5SSej4o//cHASIhG0zqizx8o+A47ukpgvIx1Clmr00Nwiqu/yA93q4H s+9qtVQF0rXzmXUAgaD+VQwANvodT9PqKNx8A2q0GDlBSlZ3XaD4Lw8XovADbeFr2I mlFU+V2PT2AnDrf4poruqSgiZcTm2D/3ucMpKT1I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388465AbfBMCiL (ORCPT ); Tue, 12 Feb 2019 21:38:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:41676 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730629AbfBMCiK (ORCPT ); Tue, 12 Feb 2019 21:38:10 -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 5F252222C2; Wed, 13 Feb 2019 02:38:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550025489; bh=TNkmIcypAoyoP3+FNg/zLJ4g6tuh4egK7HK+8TMCHKo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2iEretVhtsX587++DjSTlpqdOcIEQp/wI67834OipKQ4t/og7a7kKHIUTFqIUdoCK 2VxIqzpswpq1dV0u+w8NHXAYPFOjfHqpcZjwi2YT3lznv7K5herFIUS5UqTY+YU4dA GhPa+pzyATRJv3dQNTmckl4gxubJWV9aZFPlWxIQ= 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 4.19 40/83] bpf: fix panic in stack_map_get_build_id() on i386 and arm32 Date: Tue, 12 Feb 2019 21:36:18 -0500 Message-Id: <20190213023701.20286-40-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190213023701.20286-1-sashal@kernel.org> References: <20190213023701.20286-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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 8061a439ef18..e50ef5bca421 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