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Mon, 7 Jun 2021 22:33:20 -0400 Received: from mail-ej1-x629.google.com (mail-ej1-x629.google.com [IPv6:2a00:1450:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B7A4C061574; Mon, 7 Jun 2021 19:31:14 -0700 (PDT) Received: by mail-ej1-x629.google.com with SMTP id my49so13260413ejc.7; Mon, 07 Jun 2021 19:31:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=l7xUTKanPRGXpfqLrdmjlT+AMandQ6o+RGBfYX1FatU=; b=AErY6ZKn37TATLFP8O01VjT2RJZBMtL6Ap99J7Ehl3G2WRcL5OUkTSSznp2gOeSToO zEoLIuPyvO5+ymD59tTa3IgLkTYaDHrKydjdsT+zRA2dtV3av4pD+5QewSsX/VRPLgQV mOC6goSZOEqioVPTPFvnFgXfydLS7O/hhAtCkapqRSnikEzL6mzdYpqW5/vnHVL2lpTb DHLnY4AaDxzp1XGRRVVNdp2Vrff8tPhgje8+wsiBWkal5QBJg7/MIq53T5rZYkOtArvk EAz+mKXyKipjjhaYJulQ7umGboqYJvGsloeoHJlKVdmEoR6wnyqpYJudWkmzfMN3DDhW 1DaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=l7xUTKanPRGXpfqLrdmjlT+AMandQ6o+RGBfYX1FatU=; b=WLC96liW7aggAYgsId7bY4JiJNIgqtDBsXEhQUnhQyCd/ilGrayJ8eZ6uQ6dxlPpv5 d6YWQVTnCgdIKvN7MD+KqeKgWomLfCAa5onflcWv3utRBQrZLvxPToOMHoD5+LhRHVdI zdmN34TjbH3qfldm9DaOntgPJG6CCFjPEZ/goQQeeXjG1Z3FQp6Iy37iFhU74/u+mpoK LweEJ9BxIYMZVS86KGSvjWIdo3oDvw8GLP9+jS+s9BEcVW/bYRt6jeLOf6dpvYBMrys2 ZQaTnk7X1kbYeRbjh/n044UnQs5XAy6WU80KBPUqAKGtfCJ7eZw9DKKI525Y8kxTQ/xY xUrQ== X-Gm-Message-State: AOAM532SeOWjaiAIFWLy4B7o4WfRW9Z/y2B4WzQt/MPJp7Yd3pcbR6di 3VAbu1qsOSNQa/ljk05zNqp4J8lvxIptRJ3XUGY= X-Google-Smtp-Source: ABdhPJx/s3q9UaBPoByPhWjMqnK7/I/SFPzj33oeY1EOhWlbC3a0EWtRMrGWZRDhZWt0GXTqF9p9ZTlO08g6C1cacfw= X-Received: by 2002:a17:906:35ca:: with SMTP id p10mr20280723ejb.535.1623119472903; Mon, 07 Jun 2021 19:31:12 -0700 (PDT) MIME-Version: 1.0 References: <20210608015158.3848878-1-sunnanyong@huawei.com> In-Reply-To: From: Dongliang Mu Date: Tue, 8 Jun 2021 10:30:46 +0800 Message-ID: Subject: Re: [PATCH] net: ipv4: fix memory leak in netlbl_cipsov4_add_std To: Paul Moore Cc: Nanyong Sun , davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, Jakub Kicinski , netdev@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Jun 8, 2021 at 9:57 AM Paul Moore wrote: > > On Mon, Jun 7, 2021 at 9:19 PM Nanyong Sun wrote: > > > > Reported by syzkaller: > > BUG: memory leak > > unreferenced object 0xffff888105df7000 (size 64): > > comm "syz-executor842", pid 360, jiffies 4294824824 (age 22.546s) > > hex dump (first 32 bytes): > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > > backtrace: > > [<00000000e67ed558>] kmalloc include/linux/slab.h:590 [inline] > > [<00000000e67ed558>] kzalloc include/linux/slab.h:720 [inline] > > [<00000000e67ed558>] netlbl_cipsov4_add_std net/netlabel/netlabel_cipso_v4.c:145 [inline] > > [<00000000e67ed558>] netlbl_cipsov4_add+0x390/0x2340 net/netlabel/netlabel_cipso_v4.c:416 > > [<0000000006040154>] genl_family_rcv_msg_doit.isra.0+0x20e/0x320 net/netlink/genetlink.c:739 > > [<00000000204d7a1c>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] > > [<00000000204d7a1c>] genl_rcv_msg+0x2bf/0x4f0 net/netlink/genetlink.c:800 > > [<00000000c0d6a995>] netlink_rcv_skb+0x134/0x3d0 net/netlink/af_netlink.c:2504 > > [<00000000d78b9d2c>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811 > > [<000000009733081b>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] > > [<000000009733081b>] netlink_unicast+0x4a0/0x6a0 net/netlink/af_netlink.c:1340 > > [<00000000d5fd43b8>] netlink_sendmsg+0x789/0xc70 net/netlink/af_netlink.c:1929 > > [<000000000a2d1e40>] sock_sendmsg_nosec net/socket.c:654 [inline] > > [<000000000a2d1e40>] sock_sendmsg+0x139/0x170 net/socket.c:674 > > [<00000000321d1969>] ____sys_sendmsg+0x658/0x7d0 net/socket.c:2350 > > [<00000000964e16bc>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2404 > > [<000000001615e288>] __sys_sendmsg+0xd3/0x190 net/socket.c:2433 > > [<000000004ee8b6a5>] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:47 > > [<00000000171c7cee>] entry_SYSCALL_64_after_hwframe+0x44/0xae > > > > The memory of doi_def->map.std pointing is allocated in > > netlbl_cipsov4_add_std, but no place has freed it. It should be > > freed in cipso_v4_doi_free which frees the cipso DOI resource. > > > > Fixes: 96cb8e3313c7a ("[NetLabel]: CIPSOv4 and Unlabeled packet integration") > > Reported-by: Hulk Robot > > Signed-off-by: Nanyong Sun > > --- > > net/ipv4/cipso_ipv4.c | 1 + > > 1 file changed, 1 insertion(+) > > Nice catch, thanks for fixing this. > > Acked-by: Paul Moore > > > diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c > > index d6e3a92841e3..099259fc826a 100644 > > --- a/net/ipv4/cipso_ipv4.c > > +++ b/net/ipv4/cipso_ipv4.c > > @@ -471,6 +471,7 @@ void cipso_v4_doi_free(struct cipso_v4_doi *doi_def) > > kfree(doi_def->map.std->lvl.local); > > kfree(doi_def->map.std->cat.cipso); > > kfree(doi_def->map.std->cat.local); > > + kfree(doi_def->map.std); > > break; > > } > > kfree(doi_def); Hi kernel developers, I doubt this patch may cause invalid free in other functions where map.std is not allocated or initialized, such as netlbl_cipsov4_add_local, netlbl_cipsov4_add_pass. Take netlbl_cipsov4_add_pass as an example, any failure after the doi_def allocation failure will go to cipso_v4_doi_free, and free doi_def->map.std. static int netlbl_cipsov4_add_pass(struct genl_info *info, struct netlbl_audit *audit_info) { int ret_val; struct cipso_v4_doi *doi_def = NULL; if (!info->attrs[NLBL_CIPSOV4_A_TAGLST]) return -EINVAL; doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL); if (doi_def == NULL) return -ENOMEM; doi_def->type = CIPSO_V4_MAP_PASS; ret_val = netlbl_cipsov4_add_common(info, doi_def); if (ret_val != 0) goto add_pass_failure; ret_val = cipso_v4_doi_add(doi_def, audit_info); if (ret_val != 0) goto add_pass_failure; return 0; add_pass_failure: cipso_v4_doi_free(doi_def); return ret_val; } [1] https://elixir.bootlin.com/linux/latest/source/net/netlabel/netlabel_cipso_v4.c#L326 > > -- > > 2.18.0.huawei.25 > > -- > paul moore > www.paul-moore.com