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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A25FFC32772 for ; Tue, 23 Aug 2022 12:08:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359415AbiHWMIM (ORCPT ); Tue, 23 Aug 2022 08:08:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359373AbiHWMDq (ORCPT ); Tue, 23 Aug 2022 08:03:46 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D37BDCFFB; Tue, 23 Aug 2022 02:37:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 528626146C; Tue, 23 Aug 2022 09:36:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57E3FC433D7; Tue, 23 Aug 2022 09:36:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661247413; bh=MCxlSMJOR6HhiMSpgL2jvCmdzjbKMba/TcDZg6n5OjI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jf3VxXpt83uxwO49PMx2q635FGo+kuin2dEmr9sqjj2fWNKrIkRc4OvnLSEG3DqUz 31xkn/TaeyNpo9RXgleJ/p2W0IEVm/L4HynVPIfUv6i9LtZjvZd0rFvheegHTDKrKI GK+uKXyAQycyIL60INYQTySBe897099ziJ1Qo2ak= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hou Tao , Yonghong Song , Alexei Starovoitov Subject: [PATCH 5.10 028/158] bpf: Acquire map uref in .init_seq_private for hash map iterator Date: Tue, 23 Aug 2022 10:26:00 +0200 Message-Id: <20220823080047.230320318@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080046.056825146@linuxfoundation.org> References: <20220823080046.056825146@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hou Tao commit ef1e93d2eeb58a1f08c37b22a2314b94bc045f15 upstream. bpf_iter_attach_map() 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 bpf_iter_detach_map() as part of bpf_link_release(), or could be released in bpf_map_put_with_uref() as part of bpf_map_release(). So acquiring an extra map uref in bpf_iter_init_hash_map() and releasing it in bpf_iter_fini_hash_map(). Fixes: d6c4503cc296 ("bpf: Implement bpf iterator for hash maps") Signed-off-by: Hou Tao Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20220810080538.1845898-3-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/hashtab.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -1801,6 +1801,7 @@ static int bpf_iter_init_hash_map(void * seq_info->percpu_value_buf = value_buf; } + bpf_map_inc_with_uref(map); seq_info->map = map; seq_info->htab = container_of(map, struct bpf_htab, map); return 0; @@ -1810,6 +1811,7 @@ static void bpf_iter_fini_hash_map(void { struct bpf_iter_seq_hash_map_info *seq_info = priv_data; + bpf_map_put_with_uref(seq_info->map); kfree(seq_info->percpu_value_buf); }