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 828AEC32772 for ; Tue, 23 Aug 2022 09:48:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242912AbiHWJsd (ORCPT ); Tue, 23 Aug 2022 05:48:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352220AbiHWJqD (ORCPT ); Tue, 23 Aug 2022 05:46:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1934A13E9E; Tue, 23 Aug 2022 01:43:33 -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 3A68361338; Tue, 23 Aug 2022 08:42:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E660C4347C; Tue, 23 Aug 2022 08:42:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661244158; bh=zgSagRqsTDPggD8H4gCJX6eA/Ck+/j0sadsTwgmELKM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sMF+TEqcWgP5onym6w6RIg3O5E15R+9MnioxPDUmFkF27BBlV8vySb/3XIE9U/Vmn K4SaPpVnL+gDIaUt8TwUO9k/AzSNvuhg7qTqO4C3ruM0MNZA3m6XmHy2hLC+jAIiDN B4e0kAveEMjuuuSg+7nyfTXw/yOaSImpzdIG9S1E= 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 5.15 045/244] bpf: Acquire map uref in .init_seq_private for hash map iterator Date: Tue, 23 Aug 2022 10:23:24 +0200 Message-Id: <20220823080100.566461236@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080059.091088642@linuxfoundation.org> References: <20220823080059.091088642@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 @@ -2019,6 +2019,7 @@ 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; @@ -2028,6 +2029,7 @@ 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); }