From patchwork Tue Nov 15 03:29:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: wangyufen X-Patchwork-Id: 13043170 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 421E8C4332F for ; Tue, 15 Nov 2022 03:09:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231474AbiKODJ1 (ORCPT ); Mon, 14 Nov 2022 22:09:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230336AbiKODJ1 (ORCPT ); Mon, 14 Nov 2022 22:09:27 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 555FE646F; Mon, 14 Nov 2022 19:09:26 -0800 (PST) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NB9zQ1KSwzqSM5; Tue, 15 Nov 2022 11:05:38 +0800 (CST) Received: from localhost.localdomain (10.175.112.70) by canpemm500010.china.huawei.com (7.192.105.118) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 15 Nov 2022 11:09:24 +0800 From: Wang Yufen To: , CC: , , , , , Wang Yufen , Stanislav Fomichev Subject: [PATCH bpf v2] selftests/bpf: fix memory leak of lsm_cgroup Date: Tue, 15 Nov 2022 11:29:40 +0800 Message-ID: <1668482980-16163-1-git-send-email-wangyufen@huawei.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 X-Originating-IP: [10.175.112.70] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: kmemleak reports this issue: unreferenced object 0xffff88810b7835c0 (size 32): comm "test_progs", pid 270, jiffies 4294969007 (age 1621.315s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 03 00 00 00 03 00 00 00 0f 00 00 00 00 00 00 00 ................ backtrace: [<00000000376cdeab>] kmalloc_trace+0x27/0x110 [<000000003bcdb3b6>] selinux_sk_alloc_security+0x66/0x110 [<000000003959008f>] security_sk_alloc+0x47/0x80 [<00000000e7bc6668>] sk_prot_alloc+0xbd/0x1a0 [<0000000002d6343a>] sk_alloc+0x3b/0x940 [<000000009812a46d>] unix_create1+0x8f/0x3d0 [<000000005ed0976b>] unix_create+0xa1/0x150 [<0000000086a1d27f>] __sock_create+0x233/0x4a0 [<00000000cffe3a73>] __sys_socket_create.part.0+0xaa/0x110 [<0000000007c63f20>] __sys_socket+0x49/0xf0 [<00000000b08753c8>] __x64_sys_socket+0x42/0x50 [<00000000b56e26b3>] do_syscall_64+0x3b/0x90 [<000000009b4871b8>] entry_SYSCALL_64_after_hwframe+0x63/0xcd The issue occurs in the following scenarios: unix_create1() sk_alloc() sk_prot_alloc() security_sk_alloc() call_int_hook() hlist_for_each_entry() entry1->hook.sk_alloc_security <-- selinux_sk_alloc_security() succeeded, <-- sk->security alloced here. entry2->hook.sk_alloc_security <-- bpf_lsm_sk_alloc_security() failed goto out_free; ... <-- the sk->security not freed, memleak The core problem is that the LSM is not yet fully stacked (work is actively going on in this space) which means that some LSM hooks do not support multiple LSMs at the same time. To fix, skip the "EPERM" test when it runs in the environments that already have non-bpf lsms installed Fixes: dca85aac8895 ("selftests/bpf: lsm_cgroup functional test") Signed-off-by: Wang Yufen Cc: Stanislav Fomichev Acked-by: Stanislav Fomichev --- tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c | 17 +++++++++++++---- tools/testing/selftests/bpf/progs/lsm_cgroup.c | 8 ++++++++ 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c b/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c index 1102e4f..f117bfe 100644 --- a/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c +++ b/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c @@ -173,10 +173,12 @@ static void test_lsm_cgroup_functional(void) ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 4, "total prog count"); ASSERT_EQ(query_prog_cnt(cgroup_fd2, NULL), 1, "total prog count"); - /* AF_UNIX is prohibited. */ - fd = socket(AF_UNIX, SOCK_STREAM, 0); - ASSERT_LT(fd, 0, "socket(AF_UNIX)"); + if (!(skel->kconfig->CONFIG_SECURITY_APPARMOR + || skel->kconfig->CONFIG_SECURITY_SELINUX + || skel->kconfig->CONFIG_SECURITY_SMACK)) + /* AF_UNIX is prohibited. */ + ASSERT_LT(fd, 0, "socket(AF_UNIX)"); close(fd); /* AF_INET6 gets default policy (sk_priority). */ @@ -233,11 +235,18 @@ static void test_lsm_cgroup_functional(void) /* AF_INET6+SOCK_STREAM * AF_PACKET+SOCK_RAW + * AF_UNIX+SOCK_RAW if already have non-bpf lsms installed * listen_fd * client_fd * accepted_fd */ - ASSERT_EQ(skel->bss->called_socket_post_create2, 5, "called_create2"); + if (skel->kconfig->CONFIG_SECURITY_APPARMOR + || skel->kconfig->CONFIG_SECURITY_SELINUX + || skel->kconfig->CONFIG_SECURITY_SMACK) + /* AF_UNIX+SOCK_RAW if already have non-bpf lsms installed */ + ASSERT_EQ(skel->bss->called_socket_post_create2, 6, "called_create2"); + else + ASSERT_EQ(skel->bss->called_socket_post_create2, 5, "called_create2"); /* start_server * bind(ETH_P_ALL) diff --git a/tools/testing/selftests/bpf/progs/lsm_cgroup.c b/tools/testing/selftests/bpf/progs/lsm_cgroup.c index 4f2d60b..02c11d1 100644 --- a/tools/testing/selftests/bpf/progs/lsm_cgroup.c +++ b/tools/testing/selftests/bpf/progs/lsm_cgroup.c @@ -7,6 +7,10 @@ char _license[] SEC("license") = "GPL"; +extern bool CONFIG_SECURITY_SELINUX __kconfig __weak; +extern bool CONFIG_SECURITY_SMACK __kconfig __weak; +extern bool CONFIG_SECURITY_APPARMOR __kconfig __weak; + #ifndef AF_PACKET #define AF_PACKET 17 #endif @@ -140,6 +144,10 @@ int BPF_PROG(socket_bind2, struct socket *sock, struct sockaddr *address, int BPF_PROG(socket_alloc, struct sock *sk, int family, gfp_t priority) { called_socket_alloc++; + /* if already have non-bpf lsms installed, EPERM will cause memory leak of non-bpf lsms */ + if (CONFIG_SECURITY_SELINUX || CONFIG_SECURITY_SMACK || CONFIG_SECURITY_APPARMOR) + return 1; + if (family == AF_UNIX) return 0; /* EPERM */