From nobody Thu Dec 18 13:07:57 2025 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 44051C32774 for ; Tue, 23 Aug 2022 08:19:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242818AbiHWITH (ORCPT ); Tue, 23 Aug 2022 04:19:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242371AbiHWIOX (ORCPT ); Tue, 23 Aug 2022 04:14:23 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BE74275ED; Tue, 23 Aug 2022 01:09:49 -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 ams.source.kernel.org (Postfix) with ESMTPS id 7456FB81C23; Tue, 23 Aug 2022 08:09:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 876F5C433D7; Tue, 23 Aug 2022 08:09:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661242186; bh=DaN9Va7Ic0V+aXbPJGXb1aaLtyi0S0ejmM7VpShT7R0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f6tiBdwADb3EccjsYoYn7szA0DF+v9JR3KJTDIJmjt9vdk0hYYg7L8U5fTAzctDkn e9qcKJJHyyAb1fvSj86dZiM0uJjAJ6/+LIK1P9+Sb0pyWWFTrDxGMIrbj1fMufuy6G eD26ZvLvkWvv/O52SOoihVNjrNeKFo7uOLmaw+Co= 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 5.19 065/365] bpf: Acquire map uref in .init_seq_private for hash map iterator Date: Tue, 23 Aug 2022 09:59:26 +0200 Message-Id: <20220823080120.930953637@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080118.128342613@linuxfoundation.org> References: <20220823080118.128342613@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 @@ -2060,6 +2060,7 @@ static int bpf_iter_init_hash_map(void * seq_info->percpu_value_buf =3D value_buf; } =20 + bpf_map_inc_with_uref(map); seq_info->map =3D map; seq_info->htab =3D container_of(map, struct bpf_htab, map); return 0; @@ -2069,6 +2070,7 @@ static void bpf_iter_fini_hash_map(void { struct bpf_iter_seq_hash_map_info *seq_info =3D priv_data; =20 + bpf_map_put_with_uref(seq_info->map); kfree(seq_info->percpu_value_buf); }