From patchwork Wed Aug 10 08:05:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12940301 X-Patchwork-Delegate: bpf@iogearbox.net 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 014EAC2BB45 for ; Wed, 10 Aug 2022 07:48:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231387AbiHJHsG (ORCPT ); Wed, 10 Aug 2022 03:48:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231378AbiHJHrg (ORCPT ); Wed, 10 Aug 2022 03:47:36 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1B8B6E8A8 for ; Wed, 10 Aug 2022 00:47:34 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4M2hp51mQPzlDgk for ; Wed, 10 Aug 2022 15:46:21 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP2 (Coremail) with SMTP id Syh0CgDHsb2NYvNiIKmmAA--.61804S8; Wed, 10 Aug 2022 15:47:31 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org, Yonghong Song Cc: Andrii Nakryiko , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , KP Singh , "David S . Miller" , Jakub Kicinski , Stanislav Fomichev , Hao Luo , Jiri Olsa , John Fastabend , Lorenz Bauer , houtao1@huawei.com Subject: [PATCH bpf v2 4/9] bpf: Acquire map uref in .init_seq_private for sock{map,hash} iterator Date: Wed, 10 Aug 2022 16:05:33 +0800 Message-Id: <20220810080538.1845898-5-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20220810080538.1845898-1-houtao@huaweicloud.com> References: <20220810080538.1845898-1-houtao@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: Syh0CgDHsb2NYvNiIKmmAA--.61804S8 X-Coremail-Antispam: 1UD129KBjvJXoW7uFyUKFyfGr4rWr1DJF45Awb_yoW8KFW8pF yFyr4qkw48XF4j9Fn8Ja9rZwnayFn3Ww1jqFn3Jas5urnrWr4UWF18tFyIkF45Ary8Kry3 Jrn29F18J3y7C3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBIb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6r1S6rWUM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E 14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7 xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Y z7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2 Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s02 6x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF0x vE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4UJwCI42IY 6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aV CY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU13l1DUUUUU== X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao sock_map_iter_attach_target() acquires a map uref, and the uref may be released before or in the middle of iterating map elements. For example, the uref could be released in sock_map_iter_detach_target() as part of bpf_link_release(), or could be released in bpf_map_put_with_uref() as part of bpf_map_release(). Fixing it by acquiring an extra map uref in .init_seq_private and releasing it in .fini_seq_private. Fixes: 0365351524d7 ("net: Allow iterating sockmap and sockhash") Signed-off-by: Hou Tao Acked-by: Yonghong Song --- net/core/sock_map.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 028813dfecb0..9a9fb9487d63 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -783,13 +783,22 @@ static int sock_map_init_seq_private(void *priv_data, { struct sock_map_seq_info *info = priv_data; + bpf_map_inc_with_uref(aux->map); info->map = aux->map; return 0; } +static void sock_map_fini_seq_private(void *priv_data) +{ + struct sock_map_seq_info *info = priv_data; + + bpf_map_put_with_uref(info->map); +} + static const struct bpf_iter_seq_info sock_map_iter_seq_info = { .seq_ops = &sock_map_seq_ops, .init_seq_private = sock_map_init_seq_private, + .fini_seq_private = sock_map_fini_seq_private, .seq_priv_size = sizeof(struct sock_map_seq_info), }; @@ -1369,18 +1378,27 @@ static const struct seq_operations sock_hash_seq_ops = { }; static int sock_hash_init_seq_private(void *priv_data, - struct bpf_iter_aux_info *aux) + struct bpf_iter_aux_info *aux) { struct sock_hash_seq_info *info = priv_data; + bpf_map_inc_with_uref(aux->map); info->map = aux->map; info->htab = container_of(aux->map, struct bpf_shtab, map); return 0; } +static void sock_hash_fini_seq_private(void *priv_data) +{ + struct sock_hash_seq_info *info = priv_data; + + bpf_map_put_with_uref(info->map); +} + static const struct bpf_iter_seq_info sock_hash_iter_seq_info = { .seq_ops = &sock_hash_seq_ops, .init_seq_private = sock_hash_init_seq_private, + .fini_seq_private = sock_hash_fini_seq_private, .seq_priv_size = sizeof(struct sock_hash_seq_info), };