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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 E5234C433E0 for ; Tue, 9 Jun 2020 00:42:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C3F662076C for ; Tue, 9 Jun 2020 00:42:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591663367; bh=52liZxWS/YVroA/0/89/gMuhBgSh5CrWsVrWvpMtxo8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IMJw3UjoJ5q6vtY0pJgCtgP44zRDbTqvFgiXG2/lzqFZbTRlZYjzkZHmQHp1Bdnf9 obZ8L77c2ghrgJunPXQbI5c1U4jCLgLf541vJlIt7cCAGX53ERVdoO5UPHAZ6X6d7H bhPcx9NsEv8IPhyO7axqykTVXsp8eTVCiEA0tAxY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729075AbgFHXMX (ORCPT ); Mon, 8 Jun 2020 19:12:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:59772 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728384AbgFHXMU (ORCPT ); Mon, 8 Jun 2020 19:12:20 -0400 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 4C7C1212CC; Mon, 8 Jun 2020 23:12:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591657940; bh=52liZxWS/YVroA/0/89/gMuhBgSh5CrWsVrWvpMtxo8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HDwlKid4kRMpQBoMqO5E0dhfpM2WucrsJdCMZSl2gmfXwr4Qck+ua9JJor+CEFOWG kX/FZp20iu9P2XerocXebmYl3jWbHVWPGLvxZ3GW+K+2gf1EhkxP/CWbDNsI7S/Gyd FbXoh99o0Mjt2LgjSMFSOXdI7HKu1neJNUvOLtXQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sasha Levin , Andrii Nakryiko , Alexei Starovoitov , Yonghong Song , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 006/606] bpf: Fix bug in mmap() implementation for BPF array map Date: Mon, 8 Jun 2020 19:02:11 -0400 Message-Id: <20200608231211.3363633-6-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608231211.3363633-1-sashal@kernel.org> References: <20200608231211.3363633-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org [ Upstream commit 333291ce5055f2039afc907badaf5b66bc1adfdc ] mmap() subsystem allows user-space application to memory-map region with initial page offset. This wasn't taken into account in initial implementation of BPF array memory-mapping. This would result in wrong pages, not taking into account requested page shift, being memory-mmaped into user-space. This patch fixes this gap and adds a test for such scenario. Fixes: fc9702273e2e ("bpf: Add mmap() support for BPF_MAP_TYPE_ARRAY") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200512235925.3817805-1-andriin@fb.com Signed-off-by: Sasha Levin --- kernel/bpf/arraymap.c | 7 ++++++- tools/testing/selftests/bpf/prog_tests/mmap.c | 9 +++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 95d77770353c..1d6120fd5ba6 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -486,7 +486,12 @@ static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma) if (!(map->map_flags & BPF_F_MMAPABLE)) return -EINVAL; - return remap_vmalloc_range(vma, array_map_vmalloc_addr(array), pgoff); + if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) > + PAGE_ALIGN((u64)array->map.max_entries * array->elem_size)) + return -EINVAL; + + return remap_vmalloc_range(vma, array_map_vmalloc_addr(array), + vma->vm_pgoff + pgoff); } const struct bpf_map_ops array_map_ops = { diff --git a/tools/testing/selftests/bpf/prog_tests/mmap.c b/tools/testing/selftests/bpf/prog_tests/mmap.c index 16a814eb4d64..b0e789678aa4 100644 --- a/tools/testing/selftests/bpf/prog_tests/mmap.c +++ b/tools/testing/selftests/bpf/prog_tests/mmap.c @@ -197,6 +197,15 @@ void test_mmap(void) CHECK_FAIL(map_data->val[far] != 3 * 321); munmap(tmp2, 4 * page_size); + + /* map all 4 pages, but with pg_off=1 page, should fail */ + tmp1 = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED, + data_map_fd, page_size /* initial page shift */); + if (CHECK(tmp1 != MAP_FAILED, "adv_mmap7", "unexpected success")) { + munmap(tmp1, 4 * page_size); + goto cleanup; + } + cleanup: if (bss_mmaped) CHECK_FAIL(munmap(bss_mmaped, bss_sz)); -- 2.25.1