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GET /api/patches/809301/?format=api
HTTP 200 OK
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{
    "id": 809301,
    "url": "http://patchwork.ozlabs.org/api/patches/809301/?format=api",
    "web_url": "http://patchwork.ozlabs.org/project/netfilter-devel/patch/20170903143034.25844-1-ap420073@gmail.com/",
    "project": {
        "id": 26,
        "url": "http://patchwork.ozlabs.org/api/projects/26/?format=api",
        "name": "Netfilter Development",
        "link_name": "netfilter-devel",
        "list_id": "netfilter-devel.vger.kernel.org",
        "list_email": "netfilter-devel@vger.kernel.org",
        "web_url": null,
        "scm_url": null,
        "webscm_url": null,
        "list_archive_url": "",
        "list_archive_url_format": "",
        "commit_url_format": ""
    },
    "msgid": "<20170903143034.25844-1-ap420073@gmail.com>",
    "list_archive_url": null,
    "date": "2017-09-03T14:30:34",
    "name": "netfilter: xt_TEE: Fix potential deadlock when TEE target is inserted",
    "commit_ref": null,
    "pull_url": null,
    "state": "changes-requested",
    "archived": false,
    "hash": "7de6bf78c6fbe1f2b7b75491daebb8963fd6503e",
    "submitter": {
        "id": 68997,
        "url": "http://patchwork.ozlabs.org/api/people/68997/?format=api",
        "name": "Taehee Yoo",
        "email": "ap420073@gmail.com"
    },
    "delegate": {
        "id": 6139,
        "url": "http://patchwork.ozlabs.org/api/users/6139/?format=api",
        "username": "pablo",
        "first_name": "Pablo",
        "last_name": "Neira",
        "email": "pablo@netfilter.org"
    },
    "mbox": "http://patchwork.ozlabs.org/project/netfilter-devel/patch/20170903143034.25844-1-ap420073@gmail.com/mbox/",
    "series": [
        {
            "id": 1240,
            "url": "http://patchwork.ozlabs.org/api/series/1240/?format=api",
            "web_url": "http://patchwork.ozlabs.org/project/netfilter-devel/list/?series=1240",
            "date": "2017-09-03T14:30:34",
            "name": "netfilter: xt_TEE: Fix potential deadlock when TEE target is inserted",
            "version": 1,
            "mbox": "http://patchwork.ozlabs.org/series/1240/mbox/"
        }
    ],
    "comments": "http://patchwork.ozlabs.org/api/patches/809301/comments/",
    "check": "pending",
    "checks": "http://patchwork.ozlabs.org/api/patches/809301/checks/",
    "tags": {},
    "related": [],
    "headers": {
        "Return-Path": "<netfilter-devel-owner@vger.kernel.org>",
        "X-Original-To": "incoming@patchwork.ozlabs.org",
        "Delivered-To": "patchwork-incoming@bilbo.ozlabs.org",
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        ],
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        "X-Google-DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20161025;\n\th=x-gm-message-state:from:to:cc:subject:date:message-id;\n\tbh=OZ9eOudYsz89R+6Jf6NI/tIWXch2oIS7AphvvKQRRCI=;\n\tb=Gj/ObxhSU2PY6T3kxK7CnwhiLMVFc7suWEsbek3FpWsOo520nfkRfwTS31iesNfozN\n\tVg3qwLD+LW48CVlIvfC/uAG2GkIvVJQU86i5HN2Zq1f+ym4vZ7gnwpxuhtKlApesK0Hy\n\tQMvb/DuMUTLKXYFj1eVFlX6mf4HPkFMvaQJ6WDnyjURiMHnnwED7sxu8Lq/GYHsyFCyF\n\t0ILorviFsj+G+fp6KSnn5Ld68Grq+//IYsxIJ3NMLQO57MEVCvLMQCHxu+35+lFf8At/\n\t0pY4D57DIkodO4MB3XmCOqDXmBlYiF2vy+MTBesiebuI5WwKx5JDd7fpMq54UnRqN2Bk\n\tYcBA==",
        "X-Gm-Message-State": "AHPjjUi9BaZaEPURXponFK9gbgD8OdWL5cT/JtlQsDSHqakaleUmPfVA\n\t/VvjhzolmpyOtw==",
        "X-Google-Smtp-Source": "ADKCNb40HL2TwH1EJ0nKHnKs6xQx9UikCDTd8m/T1vPqg9hqy0sEZHLrcTcDVgItsiLQqbYVLysFMg==",
        "X-Received": "by 10.99.114.76 with SMTP id c12mr9073772pgn.22.1504449041327;\n\tSun, 03 Sep 2017 07:30:41 -0700 (PDT)",
        "From": "Taehee Yoo <ap420073@gmail.com>",
        "To": "pablo@netfilter.org, netfilter-devel@vger.kernel.org",
        "Cc": "ap420073@gmail.com",
        "Subject": "[PATCH] netfilter: xt_TEE: Fix potential deadlock when TEE target\n\tis inserted",
        "Date": "Sun,  3 Sep 2017 23:30:34 +0900",
        "Message-Id": "<20170903143034.25844-1-ap420073@gmail.com>",
        "X-Mailer": "git-send-email 2.9.3",
        "Sender": "netfilter-devel-owner@vger.kernel.org",
        "Precedence": "bulk",
        "List-ID": "<netfilter-devel.vger.kernel.org>",
        "X-Mailing-List": "netfilter-devel@vger.kernel.org"
    },
    "content": "When xt_TEE target is inserted, lockdep warns about possible\nDEADLOCK situation. to avoid deadlock situation\nthe register_netdevice_notifier() should be called by only init routine.\n\nreproduce command is :\n   # iptables -I INPUT -j TEE --oif enp3s0 --gateway 192.168.0.1\n\nwarning message is :\n\n[  115.182917] WARNING: possible circular locking dependency detected\n[  115.189846] 4.13.0-rc1+ #68 Not tainted\n[  115.194141] ------------------------------------------------------\n[  115.201065] iptables/1283 is trying to acquire lock:\n[  115.206627]  (rtnl_mutex){+.+.+.}, at: [<ffffffff8236f0d7>] rtnl_lock+0x17/0x20\n[  115.214842]\n[  115.214842] but task is already holding lock:\n[  115.221378]  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff8273ab0d>] ip_setsockopt+0x6d/0xb0\n[  115.230462]\n[  115.230462] which lock already depends on the new lock.\n[  115.230462]\n[  115.239627]\n[  115.239627] the existing dependency chain (in reverse order) is:\n[  115.248012]\n[  115.248012] -> #1 (sk_lock-AF_INET){+.+.+.}:\n[  115.254472]        lock_acquire+0x190/0x370\n[  115.259165]        lock_sock_nested+0xb8/0x100\n[  115.264148]        do_ip_setsockopt.isra.16+0x140/0x24f0\n[  115.270125]        ip_setsockopt+0x34/0xb0\n[  115.274742]        udp_setsockopt+0x1b/0x30\n[  115.279455]        sock_common_setsockopt+0x78/0xf0\n[  115.284937]        SyS_setsockopt+0x11c/0x220\n[  115.289835]        do_syscall_64+0x187/0x410\n[  115.294638]        return_from_SYSCALL_64+0x0/0x7a\n[  115.300025]\n[  115.300025] -> #0 (rtnl_mutex){+.+.+.}:\n[  115.306030]        __lock_acquire+0x4114/0x47c0\n[  115.311132]        lock_acquire+0x190/0x370\n[  115.315844]        __mutex_lock+0xef/0x1460\n[  115.320555]        mutex_lock_nested+0x1b/0x20\n[  115.325558]        rtnl_lock+0x17/0x20\n[  115.329785]        register_netdevice_notifier+0x6f/0x4f0\n[  115.335851]        tee_tg_check+0x19b/0x260\n[  115.340562]        xt_check_target+0x1f5/0x6c0\n[  115.345569]        find_check_entry.isra.7+0x62f/0x960\n[  115.351353]        translate_table+0xcf2/0x1830\n[  115.356454]        do_ipt_set_ctl+0x1ff/0x3a0\n[  115.361362]        nf_setsockopt+0x61/0xc0\n[  115.365977]        ip_setsockopt+0x82/0xb0\n[  115.370592]        raw_setsockopt+0x73/0xa0\n[  115.375304]        sock_common_setsockopt+0x78/0xf0\n[  115.380793]        SyS_setsockopt+0x11c/0x220\n[  115.385701]        entry_SYSCALL_64_fastpath+0x1c/0xb1\n[  115.391478]\n[  115.391478] other info that might help us debug this:\n[  115.391478]\n[  115.400511]  Possible unsafe locking scenario:\n[  115.400511]\n[  115.407176]        CPU0                    CPU1\n[  115.412270]        ----                    ----\n[  115.417364]   lock(sk_lock-AF_INET);\n[  115.421394]                                lock(rtnl_mutex);\n[  115.427760]                                lock(sk_lock-AF_INET);\n[  115.434723]   lock(rtnl_mutex);\n[  115.438267]\n[  115.438267]  *** DEADLOCK ***\n\n[ ... ]\n\nSigned-off-by: Taehee Yoo <ap420073@gmail.com>\n---\n include/uapi/linux/netfilter/xt_TEE.h |  3 +-\n net/netfilter/xt_TEE.c                | 90 ++++++++++++++++++++++-------------\n 2 files changed, 59 insertions(+), 34 deletions(-)",
    "diff": "diff --git a/include/uapi/linux/netfilter/xt_TEE.h b/include/uapi/linux/netfilter/xt_TEE.h\nindex 0109202..4b7eae4 100644\n--- a/include/uapi/linux/netfilter/xt_TEE.h\n+++ b/include/uapi/linux/netfilter/xt_TEE.h\n@@ -2,10 +2,11 @@\n #define _XT_TEE_TARGET_H\n \n #include <linux/netfilter.h>\n+#include <linux/if.h>\n \n struct xt_tee_tginfo {\n \tunion nf_inet_addr gw;\n-\tchar oif[16];\n+\tchar oif[IFNAMSIZ];\n \n \t/* used internally by the kernel */\n \tstruct xt_tee_priv *priv __attribute__((aligned(8)));\ndiff --git a/net/netfilter/xt_TEE.c b/net/netfilter/xt_TEE.c\nindex 86b0580..98fac9f 100644\n--- a/net/netfilter/xt_TEE.c\n+++ b/net/netfilter/xt_TEE.c\n@@ -12,19 +12,20 @@\n  */\n #include <linux/module.h>\n #include <linux/skbuff.h>\n-#include <linux/route.h>\n #include <linux/netfilter/x_tables.h>\n-#include <net/route.h>\n #include <net/netfilter/ipv4/nf_dup_ipv4.h>\n #include <net/netfilter/ipv6/nf_dup_ipv6.h>\n #include <linux/netfilter/xt_TEE.h>\n \n struct xt_tee_priv {\n-\tstruct notifier_block\tnotifier;\n \tstruct xt_tee_tginfo\t*tginfo;\n+\tstruct net\t\t*net;\n+\tstruct list_head\tlist;\n \tint\t\t\toif;\n };\n \n+static LIST_HEAD(tee_tg_list);\n+static DEFINE_MUTEX(list_mutex);\n static const union nf_inet_addr tee_zero_address;\n \n static unsigned int\n@@ -55,59 +56,69 @@ static int tee_netdev_event(struct notifier_block *this, unsigned long event,\n \t\t\t    void *ptr)\n {\n \tstruct net_device *dev = netdev_notifier_info_to_dev(ptr);\n+\tstruct net *net = dev_net(dev);\n \tstruct xt_tee_priv *priv;\n \n-\tpriv = container_of(this, struct xt_tee_priv, notifier);\n-\tswitch (event) {\n-\tcase NETDEV_REGISTER:\n-\t\tif (!strcmp(dev->name, priv->tginfo->oif))\n-\t\t\tpriv->oif = dev->ifindex;\n-\t\tbreak;\n-\tcase NETDEV_UNREGISTER:\n-\t\tif (dev->ifindex == priv->oif)\n-\t\t\tpriv->oif = -1;\n-\t\tbreak;\n-\tcase NETDEV_CHANGENAME:\n-\t\tif (!strcmp(dev->name, priv->tginfo->oif))\n-\t\t\tpriv->oif = dev->ifindex;\n-\t\telse if (dev->ifindex == priv->oif)\n-\t\t\tpriv->oif = -1;\n-\t\tbreak;\n+\tmutex_lock(&list_mutex);\n+\tlist_for_each_entry(priv, &tee_tg_list, list) {\n+\t\tswitch (event) {\n+\t\tcase NETDEV_REGISTER:\n+\t\t\tif (!strcmp(dev->name, priv->tginfo->oif) &&\n+\t\t\t    net_eq(net, priv->net))\n+\t\t\t\tpriv->oif = dev->ifindex;\n+\t\t\tbreak;\n+\t\tcase NETDEV_UNREGISTER:\n+\t\t\tif ((dev->ifindex == priv->oif) &&\n+\t\t\t    net_eq(net, priv->net))\n+\t\t\t\tpriv->oif = -1;\n+\t\t\tbreak;\n+\t\tcase NETDEV_CHANGENAME:\n+\t\t\tif (!strcmp(dev->name, priv->tginfo->oif) &&\n+\t\t\t    net_eq(net, priv->net))\n+\t\t\t\tpriv->oif = dev->ifindex;\n+\t\t\telse if ((dev->ifindex == priv->oif) &&\n+\t\t\t\t net_eq(net, priv->net))\n+\t\t\t\tpriv->oif = -1;\n+\t\t\tbreak;\n+\t\t}\n \t}\n+\tmutex_unlock(&list_mutex);\n \n \treturn NOTIFY_DONE;\n }\n \n+static struct notifier_block tee_dev_notifier = {\n+\t.notifier_call\t= tee_netdev_event,\n+};\n+\n static int tee_tg_check(const struct xt_tgchk_param *par)\n {\n \tstruct xt_tee_tginfo *info = par->targinfo;\n \tstruct xt_tee_priv *priv;\n \n \t/* 0.0.0.0 and :: not allowed */\n-\tif (memcmp(&info->gw, &tee_zero_address,\n-\t\t   sizeof(tee_zero_address)) == 0)\n+\tif (nf_inet_addr_cmp(&info->gw, &tee_zero_address)) {\n+\t\tpr_info(\"TEE: Invalid gateway address\\n\");\n \t\treturn -EINVAL;\n+\t}\n \n \tif (info->oif[0]) {\n-\t\tint ret;\n-\n-\t\tif (info->oif[sizeof(info->oif)-1] != '\\0')\n+\t\tif (info->oif[sizeof(info->oif) - 1] != '\\0') {\n+\t\t\tpr_info(\"TEE: Invalid oif name\\n\");\n \t\t\treturn -EINVAL;\n+\t\t}\n \n \t\tpriv = kzalloc(sizeof(*priv), GFP_KERNEL);\n \t\tif (priv == NULL)\n \t\t\treturn -ENOMEM;\n \n \t\tpriv->tginfo  = info;\n+\t\tpriv->net     = par->net;\n \t\tpriv->oif     = -1;\n-\t\tpriv->notifier.notifier_call = tee_netdev_event;\n \t\tinfo->priv    = priv;\n-\n-\t\tret = register_netdevice_notifier(&priv->notifier);\n-\t\tif (ret) {\n-\t\t\tkfree(priv);\n-\t\t\treturn ret;\n-\t\t}\n+\t\tmutex_lock(&list_mutex);\n+\t\tlist_add(&priv->list, &tee_tg_list);\n+\t\tmutex_unlock(&list_mutex);\n \t} else\n \t\tinfo->priv = NULL;\n \n@@ -120,8 +131,10 @@ static void tee_tg_destroy(const struct xt_tgdtor_param *par)\n \tstruct xt_tee_tginfo *info = par->targinfo;\n \n \tif (info->priv) {\n-\t\tunregister_netdevice_notifier(&info->priv->notifier);\n+\t\tmutex_lock(&list_mutex);\n+\t\tlist_del(&info->priv->list);\n \t\tkfree(info->priv);\n+\t\tmutex_unlock(&list_mutex);\n \t}\n \tstatic_key_slow_dec(&xt_tee_enabled);\n }\n@@ -155,11 +168,22 @@ static struct xt_target tee_tg_reg[] __read_mostly = {\n \n static int __init tee_tg_init(void)\n {\n-\treturn xt_register_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));\n+\tint ret;\n+\n+\tret = xt_register_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));\n+\tif (ret)\n+\t\treturn ret;\n+\n+\tret = register_netdevice_notifier(&tee_dev_notifier);\n+\tif (ret)\n+\t\txt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));\n+\n+\treturn ret;\n }\n \n static void __exit tee_tg_exit(void)\n {\n+\tunregister_netdevice_notifier(&tee_dev_notifier);\n \txt_unregister_targets(tee_tg_reg, ARRAY_SIZE(tee_tg_reg));\n }\n \n",
    "prefixes": []
}