From patchwork Thu Dec 30 19:55:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Skripkin X-Patchwork-Id: 529092 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 0EEABC433F5 for ; Thu, 30 Dec 2021 19:55:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240712AbhL3Tzy (ORCPT ); Thu, 30 Dec 2021 14:55:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237051AbhL3Tzx (ORCPT ); Thu, 30 Dec 2021 14:55:53 -0500 Received: from mail-lf1-x12a.google.com (mail-lf1-x12a.google.com [IPv6:2a00:1450:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02A08C061574; Thu, 30 Dec 2021 11:55:52 -0800 (PST) Received: by mail-lf1-x12a.google.com with SMTP id h2so45896606lfv.9; Thu, 30 Dec 2021 11:55:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=wf118paxagDJe0BrTL1UFbWHYfGXmH7eOtC5eeaiIgI=; b=d+xP+k03ZvWgl5IMd5D2vhU1nsZndGBUloMtFMtDSEpWz2dGXzcwJts3k5j7FdaVM7 VVHBHpn6SgXXI8+1O+A/OjYLPceom8Akg2angU5/TTQRKpLV3VFIKUHi9ujnGLHYARIz Pt7I6fFsrWU2mHMFlMZm0UBWglKYA7kUBI/V5mAujkKiTL0IchOMZgWNeoun8FSqEKcE 6qqxELTDO29zHwBWYUYvf28K+VUX5VnD8Z1P0fJpxoIZ4Bc/B8keVCx4esqtwEzEMDbs 3uDkEybpjc2+jxcLns1E5EyCtC8V5haHtLv9Owr4N40XJcq+87DFS+vtIv2xobn5BqTc PfVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=wf118paxagDJe0BrTL1UFbWHYfGXmH7eOtC5eeaiIgI=; b=AP1iW/197CqMuInComDt+zu8r1lLggUyWE+UzPKqR1mgRWl+/y49lVnk2I4VgNdjjA ox8hy+/uWXW70btlB65fWFmO+yv0FwUwUxLTJphsL0qxW5Dl0c6NExusRLRuRmbYsaBz 3E5Sb5zFJEgYQlTYYHV7XCIFkf4WX2Bo2uZTqf3qUSePi6riFxZCbp6mZhmyLrSnENUj z+ep4TKTUQr7iOvGu3EzI5pbUqTsE2j/Q2Tp3daDkZyoa8p7yFtOnodfNveVHSy1ir8u 2x3PqAEK3VBrDYPGodELncq6fh2VD02fnuFpbHyorSzpKVbyGrQesUBWUMC4QYUgVDVW rgBA== X-Gm-Message-State: AOAM533wiWeUlqiyxyFFGuADIL3IqHK/j7En1n2XZADscaLUEien6YyQ 9D1i5Z9ZxVdYTNNuQWV/Pxs= X-Google-Smtp-Source: ABdhPJwIOPSrQ/q1lNA3B+Zx9QbSUn8ZPpEzm+qUl8XrQcWtL8SrM5JoVd7A0t62XpgQDP8vyAdnzA== X-Received: by 2002:ac2:5458:: with SMTP id d24mr28898253lfn.38.1640894151047; Thu, 30 Dec 2021 11:55:51 -0800 (PST) Received: from localhost.localdomain ([94.103.235.97]) by smtp.gmail.com with ESMTPSA id v2sm2553914ljg.46.2021.12.30.11.55.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Dec 2021 11:55:50 -0800 (PST) From: Pavel Skripkin To: johannes@sipsolutions.net, davem@davemloft.net, kuba@kernel.org, me@bobcopeland.com Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pavel Skripkin , syzbot+860268315ba86ea6b96b@syzkaller.appspotmail.com Subject: [PATCH] mac80211: mesh: embedd mesh_paths and mpp_paths into ieee80211_if_mesh Date: Thu, 30 Dec 2021 22:55:47 +0300 Message-Id: <20211230195547.23977-1-paskripkin@gmail.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Syzbot hit NULL deref in rhashtable_free_and_destroy(). The problem was in mesh_paths and mpp_paths being NULL. mesh_pathtbl_init() could fail in case of memory allocation failure, but nobody cared, since ieee80211_mesh_init_sdata() returns void. It led to leaving 2 pointers as NULL. Syzbot has found null deref on exit path, but it could happen anywhere else, because code assumes these pointers are valid. Since all ieee80211_*_setup_sdata functions are void and do not fail, let's embedd mesh_paths and mpp_paths into parent struct to avoid adding error handling on higher levels and follow the pattern of others setup_sdata functions Fixes: 60854fd94573 ("mac80211: mesh: convert path table to rhashtable") Reported-and-tested-by: syzbot+860268315ba86ea6b96b@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin --- Happy New Year and Merry Christmas! :) With regards, Pavel Skripkin --- net/mac80211/ieee80211_i.h | 24 +++++++++- net/mac80211/mesh.h | 22 +-------- net/mac80211/mesh_pathtbl.c | 89 +++++++++++++------------------------ 3 files changed, 54 insertions(+), 81 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 5666bbb8860b..482c98ede19b 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -647,6 +647,26 @@ struct mesh_csa_settings { struct cfg80211_csa_settings settings; }; +/** + * struct mesh_table + * + * @known_gates: list of known mesh gates and their mpaths by the station. The + * gate's mpath may or may not be resolved and active. + * @gates_lock: protects updates to known_gates + * @rhead: the rhashtable containing struct mesh_paths, keyed by dest addr + * @walk_head: linked list containing all mesh_path objects + * @walk_lock: lock protecting walk_head + * @entries: number of entries in the table + */ +struct mesh_table { + struct hlist_head known_gates; + spinlock_t gates_lock; + struct rhashtable rhead; + struct hlist_head walk_head; + spinlock_t walk_lock; + atomic_t entries; /* Up to MAX_MESH_NEIGHBOURS */ +}; + struct ieee80211_if_mesh { struct timer_list housekeeping_timer; struct timer_list mesh_path_timer; @@ -721,8 +741,8 @@ struct ieee80211_if_mesh { /* offset from skb->data while building IE */ int meshconf_offset; - struct mesh_table *mesh_paths; - struct mesh_table *mpp_paths; /* Store paths for MPP&MAP */ + struct mesh_table mesh_paths; + struct mesh_table mpp_paths; /* Store paths for MPP&MAP */ int mesh_paths_generation; int mpp_paths_generation; }; diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h index 77080b4f87b8..b2b717a78114 100644 --- a/net/mac80211/mesh.h +++ b/net/mac80211/mesh.h @@ -127,26 +127,6 @@ struct mesh_path { u32 path_change_count; }; -/** - * struct mesh_table - * - * @known_gates: list of known mesh gates and their mpaths by the station. The - * gate's mpath may or may not be resolved and active. - * @gates_lock: protects updates to known_gates - * @rhead: the rhashtable containing struct mesh_paths, keyed by dest addr - * @walk_head: linked list containing all mesh_path objects - * @walk_lock: lock protecting walk_head - * @entries: number of entries in the table - */ -struct mesh_table { - struct hlist_head known_gates; - spinlock_t gates_lock; - struct rhashtable rhead; - struct hlist_head walk_head; - spinlock_t walk_lock; - atomic_t entries; /* Up to MAX_MESH_NEIGHBOURS */ -}; - /* Recent multicast cache */ /* RMC_BUCKETS must be a power of 2, maximum 256 */ #define RMC_BUCKETS 256 @@ -308,7 +288,7 @@ int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata, void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta); void mesh_path_flush_pending(struct mesh_path *mpath); void mesh_path_tx_pending(struct mesh_path *mpath); -int mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata); +void mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata); void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata); int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr); void mesh_path_timer(struct timer_list *t); diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c index 7cab1cf09bf1..acc1c299f1ae 100644 --- a/net/mac80211/mesh_pathtbl.c +++ b/net/mac80211/mesh_pathtbl.c @@ -47,32 +47,24 @@ static void mesh_path_rht_free(void *ptr, void *tblptr) mesh_path_free_rcu(tbl, mpath); } -static struct mesh_table *mesh_table_alloc(void) +static void mesh_table_init(struct mesh_table *tbl) { - struct mesh_table *newtbl; + INIT_HLIST_HEAD(&tbl->known_gates); + INIT_HLIST_HEAD(&tbl->walk_head); + atomic_set(&tbl->entries, 0); + spin_lock_init(&tbl->gates_lock); + spin_lock_init(&tbl->walk_lock); - newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC); - if (!newtbl) - return NULL; - - INIT_HLIST_HEAD(&newtbl->known_gates); - INIT_HLIST_HEAD(&newtbl->walk_head); - atomic_set(&newtbl->entries, 0); - spin_lock_init(&newtbl->gates_lock); - spin_lock_init(&newtbl->walk_lock); - if (rhashtable_init(&newtbl->rhead, &mesh_rht_params)) { - kfree(newtbl); - return NULL; - } - - return newtbl; + /* rhashtable_init() may fail only in case of wrong + * mesh_rht_params + */ + WARN_ON(rhashtable_init(&tbl->rhead, &mesh_rht_params)); } static void mesh_table_free(struct mesh_table *tbl) { rhashtable_free_and_destroy(&tbl->rhead, mesh_path_rht_free, tbl); - kfree(tbl); } /** @@ -238,13 +230,13 @@ static struct mesh_path *mpath_lookup(struct mesh_table *tbl, const u8 *dst, struct mesh_path * mesh_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst) { - return mpath_lookup(sdata->u.mesh.mesh_paths, dst, sdata); + return mpath_lookup(&sdata->u.mesh.mesh_paths, dst, sdata); } struct mesh_path * mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst) { - return mpath_lookup(sdata->u.mesh.mpp_paths, dst, sdata); + return mpath_lookup(&sdata->u.mesh.mpp_paths, dst, sdata); } static struct mesh_path * @@ -281,7 +273,7 @@ __mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx) struct mesh_path * mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx) { - return __mesh_path_lookup_by_idx(sdata->u.mesh.mesh_paths, idx); + return __mesh_path_lookup_by_idx(&sdata->u.mesh.mesh_paths, idx); } /** @@ -296,7 +288,7 @@ mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx) struct mesh_path * mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx) { - return __mesh_path_lookup_by_idx(sdata->u.mesh.mpp_paths, idx); + return __mesh_path_lookup_by_idx(&sdata->u.mesh.mpp_paths, idx); } /** @@ -309,7 +301,7 @@ int mesh_path_add_gate(struct mesh_path *mpath) int err; rcu_read_lock(); - tbl = mpath->sdata->u.mesh.mesh_paths; + tbl = &mpath->sdata->u.mesh.mesh_paths; spin_lock_bh(&mpath->state_lock); if (mpath->is_gate) { @@ -418,7 +410,7 @@ struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata, if (!new_mpath) return ERR_PTR(-ENOMEM); - tbl = sdata->u.mesh.mesh_paths; + tbl = &sdata->u.mesh.mesh_paths; spin_lock_bh(&tbl->walk_lock); mpath = rhashtable_lookup_get_insert_fast(&tbl->rhead, &new_mpath->rhash, @@ -460,7 +452,7 @@ int mpp_path_add(struct ieee80211_sub_if_data *sdata, return -ENOMEM; memcpy(new_mpath->mpp, mpp, ETH_ALEN); - tbl = sdata->u.mesh.mpp_paths; + tbl = &sdata->u.mesh.mpp_paths; spin_lock_bh(&tbl->walk_lock); ret = rhashtable_lookup_insert_fast(&tbl->rhead, @@ -489,7 +481,7 @@ int mpp_path_add(struct ieee80211_sub_if_data *sdata, void mesh_plink_broken(struct sta_info *sta) { struct ieee80211_sub_if_data *sdata = sta->sdata; - struct mesh_table *tbl = sdata->u.mesh.mesh_paths; + struct mesh_table *tbl = &sdata->u.mesh.mesh_paths; static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; struct mesh_path *mpath; @@ -548,7 +540,7 @@ static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath) void mesh_path_flush_by_nexthop(struct sta_info *sta) { struct ieee80211_sub_if_data *sdata = sta->sdata; - struct mesh_table *tbl = sdata->u.mesh.mesh_paths; + struct mesh_table *tbl = &sdata->u.mesh.mesh_paths; struct mesh_path *mpath; struct hlist_node *n; @@ -563,7 +555,7 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta) static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata, const u8 *proxy) { - struct mesh_table *tbl = sdata->u.mesh.mpp_paths; + struct mesh_table *tbl = &sdata->u.mesh.mpp_paths; struct mesh_path *mpath; struct hlist_node *n; @@ -597,8 +589,8 @@ static void table_flush_by_iface(struct mesh_table *tbl) */ void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata) { - table_flush_by_iface(sdata->u.mesh.mesh_paths); - table_flush_by_iface(sdata->u.mesh.mpp_paths); + table_flush_by_iface(&sdata->u.mesh.mesh_paths); + table_flush_by_iface(&sdata->u.mesh.mpp_paths); } /** @@ -644,7 +636,7 @@ int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr) /* flush relevant mpp entries first */ mpp_flush_by_proxy(sdata, addr); - err = table_path_del(sdata->u.mesh.mesh_paths, sdata, addr); + err = table_path_del(&sdata->u.mesh.mesh_paths, sdata, addr); sdata->u.mesh.mesh_paths_generation++; return err; } @@ -682,7 +674,7 @@ int mesh_path_send_to_gates(struct mesh_path *mpath) struct mesh_path *gate; bool copy = false; - tbl = sdata->u.mesh.mesh_paths; + tbl = &sdata->u.mesh.mesh_paths; rcu_read_lock(); hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) { @@ -762,29 +754,10 @@ void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop) mesh_path_tx_pending(mpath); } -int mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata) +void mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata) { - struct mesh_table *tbl_path, *tbl_mpp; - int ret; - - tbl_path = mesh_table_alloc(); - if (!tbl_path) - return -ENOMEM; - - tbl_mpp = mesh_table_alloc(); - if (!tbl_mpp) { - ret = -ENOMEM; - goto free_path; - } - - sdata->u.mesh.mesh_paths = tbl_path; - sdata->u.mesh.mpp_paths = tbl_mpp; - - return 0; - -free_path: - mesh_table_free(tbl_path); - return ret; + mesh_table_init(&sdata->u.mesh.mesh_paths); + mesh_table_init(&sdata->u.mesh.mpp_paths); } static @@ -806,12 +779,12 @@ void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata, void mesh_path_expire(struct ieee80211_sub_if_data *sdata) { - mesh_path_tbl_expire(sdata, sdata->u.mesh.mesh_paths); - mesh_path_tbl_expire(sdata, sdata->u.mesh.mpp_paths); + mesh_path_tbl_expire(sdata, &sdata->u.mesh.mesh_paths); + mesh_path_tbl_expire(sdata, &sdata->u.mesh.mpp_paths); } void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata) { - mesh_table_free(sdata->u.mesh.mesh_paths); - mesh_table_free(sdata->u.mesh.mpp_paths); + mesh_table_free(&sdata->u.mesh.mesh_paths); + mesh_table_free(&sdata->u.mesh.mpp_paths); }