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 X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE572ECDE46 for ; Thu, 25 Oct 2018 14:11:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A64522086C for ; Thu, 25 Oct 2018 14:11:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="VgmbkGPj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A64522086C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728234AbeJYWoa (ORCPT ); Thu, 25 Oct 2018 18:44:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:53298 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727531AbeJYWo3 (ORCPT ); Thu, 25 Oct 2018 18:44:29 -0400 Received: from sasha-vm.mshome.net (unknown [167.98.65.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2FA0220848; Thu, 25 Oct 2018 14:11:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540476693; bh=CayU1PeIyciP/UMMnVLIWDmf3xqeTylmprLAt5eaFyw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VgmbkGPj0GWNsWkIHLJvM/SNMYf6E+9fIKyF2sKIcBVHioF1MhU3G54V14BAU2u39 ukGRHv8EIPdEoi6YITky9HBafQNlZxihvLbsidBRGL57MFLMimSMpwhUACnsBNWagj HAakmpsWWXOfupWQwthINKqF7NCl3agwH9Z4d+qo= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: John Fastabend , Daniel Borkmann , Sasha Levin Subject: [PATCH AUTOSEL 4.14 27/46] bpf: sockmap, map_release does not hold refcnt for pinned maps Date: Thu, 25 Oct 2018 10:10:34 -0400 Message-Id: <20181025141053.213330-27-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181025141053.213330-1-sashal@kernel.org> References: <20181025141053.213330-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: John Fastabend [ Upstream commit ba6b8de423f8d0dee48d6030288ed81c03ddf9f0 ] Relying on map_release hook to decrement the reference counts when a map is removed only works if the map is not being pinned. In the pinned case the ref is decremented immediately and the BPF programs released. After this BPF programs may not be in-use which is not what the user would expect. This patch moves the release logic into bpf_map_put_uref() and brings sockmap in-line with how a similar case is handled in prog array maps. Fixes: 3d9e952697de ("bpf: sockmap, fix leaking maps with attached but not detached progs") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- include/linux/bpf.h | 2 +- kernel/bpf/arraymap.c | 3 ++- kernel/bpf/sockmap.c | 4 ++-- kernel/bpf/syscall.c | 4 ++-- 4 files changed, 7 insertions(+), 6 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 5c5be80ce802..c9d2a1a3ef11 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -27,6 +27,7 @@ struct bpf_map_ops { void (*map_release)(struct bpf_map *map, struct file *map_file); void (*map_free)(struct bpf_map *map); int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key); + void (*map_release_uref)(struct bpf_map *map); /* funcs callable from userspace and from eBPF programs */ void *(*map_lookup_elem)(struct bpf_map *map, void *key); @@ -300,7 +301,6 @@ int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value); int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, void *key, void *value, u64 map_flags); int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); -void bpf_fd_array_map_clear(struct bpf_map *map); int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file, void *key, void *value, u64 map_flags); int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index f57d0bdf3c9e..a8f55ea4146b 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -467,7 +467,7 @@ static u32 prog_fd_array_sys_lookup_elem(void *ptr) } /* decrement refcnt of all bpf_progs that are stored in this map */ -void bpf_fd_array_map_clear(struct bpf_map *map) +static void bpf_fd_array_map_clear(struct bpf_map *map) { struct bpf_array *array = container_of(map, struct bpf_array, map); int i; @@ -485,6 +485,7 @@ const struct bpf_map_ops prog_array_map_ops = { .map_fd_get_ptr = prog_fd_array_get_ptr, .map_fd_put_ptr = prog_fd_array_put_ptr, .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem, + .map_release_uref = bpf_fd_array_map_clear, }; static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file, diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index 20eaddfa691c..22991e19c01c 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -875,7 +875,7 @@ static int sock_map_update_elem(struct bpf_map *map, return err; } -static void sock_map_release(struct bpf_map *map, struct file *map_file) +static void sock_map_release(struct bpf_map *map) { struct bpf_stab *stab = container_of(map, struct bpf_stab, map); struct bpf_prog *orig; @@ -895,7 +895,7 @@ const struct bpf_map_ops sock_map_ops = { .map_get_next_key = sock_map_get_next_key, .map_update_elem = sock_map_update_elem, .map_delete_elem = sock_map_delete_elem, - .map_release = sock_map_release, + .map_release_uref = sock_map_release, }; BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock, diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4e933219fec6..ea22d0b6a9f0 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -214,8 +214,8 @@ static void bpf_map_free_deferred(struct work_struct *work) static void bpf_map_put_uref(struct bpf_map *map) { if (atomic_dec_and_test(&map->usercnt)) { - if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) - bpf_fd_array_map_clear(map); + if (map->ops->map_release_uref) + map->ops->map_release_uref(map); } } -- 2.17.1