From patchwork Mon Apr 25 15:37:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maciej Fijalkowski X-Patchwork-Id: 12825901 X-Patchwork-Delegate: bpf@iogearbox.net 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 09320C433FE for ; Mon, 25 Apr 2022 15:38:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242911AbiDYPlE (ORCPT ); Mon, 25 Apr 2022 11:41:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242631AbiDYPlC (ORCPT ); Mon, 25 Apr 2022 11:41:02 -0400 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A6F1923168; Mon, 25 Apr 2022 08:37:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1650901078; x=1682437078; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=IcJbN6NxiwXMP2nWjVSsUpiTnQLizWST4HfC5OQoUMM=; b=S0ul/p0BCPfftCJFOTdgsjYECTXYL3wr8Qw//YEa84Gz0aJRNtkPxGpo Hiq9cx564ctxzogLWeGbMEqW8O5SmIMSW5JiNYC+jyvtz5Pkw4BcEwRTq xZif0ubunEnUcaje61/XXs7UQoUoERwQM24pzKuCcSgJuQbKkQfDTajTO IB8orAgaAwdAMFPvhgkBzNHiw+fRfVgHKWHuXYgehhnRaLvdyGHhKV/Wo z9iwjGT1U9FiHuzRjCM9rhBTivslZGY2f7E+hAIgXLXbNJZcsWyb60uXd KD7vzB62Woc5xKfjtZ55ZUc6ttMvDIszWL6sEaSGd9iKDUEwEaNMh5sc9 A==; X-IronPort-AV: E=McAfee;i="6400,9594,10328"; a="264800397" X-IronPort-AV: E=Sophos;i="5.90,288,1643702400"; d="scan'208";a="264800397" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Apr 2022 08:37:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,288,1643702400"; d="scan'208";a="537643447" Received: from boxer.igk.intel.com ([10.102.20.173]) by orsmga002.jf.intel.com with ESMTP; 25 Apr 2022 08:37:56 -0700 From: Maciej Fijalkowski To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andriin@kernel.org Cc: netdev@vger.kernel.org, magnus.karlsson@intel.com, Maciej Fijalkowski Subject: [PATCH bpf] xsk: fix possible crash when multiple sockets are created Date: Mon, 25 Apr 2022 17:37:45 +0200 Message-Id: <20220425153745.481322-1-maciej.fijalkowski@intel.com> X-Mailer: git-send-email 2.33.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Fix a crash that happens if an Rx only socket is created first, then a second socket is created that is Tx only and bound to the same umem as the first socket and also the same netdev and queue_id together with the XDP_SHARED_UMEM flag. In this specific case, the tx_descs array page pool was not created by the first socket as it was an Rx only socket. When the second socket is bound it needs this tx_descs array of this shared page pool as it has a Tx component, but unfortunately it was never allocated, leading to a crash. Note that this array is only used for zero-copy drivers using the batched Tx APIs, currently only ice and i40e. [ 5511.150360] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 5511.158419] #PF: supervisor write access in kernel mode [ 5511.164472] #PF: error_code(0x0002) - not-present page [ 5511.170416] PGD 0 P4D 0 [ 5511.173347] Oops: 0002 [#1] PREEMPT SMP PTI [ 5511.178186] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G E 5.18.0-rc1+ #97 [ 5511.187245] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016 [ 5511.198418] RIP: 0010:xsk_tx_peek_release_desc_batch+0x198/0x310 [ 5511.205375] Code: c0 83 c6 01 84 c2 74 6d 8d 46 ff 23 07 44 89 e1 48 83 c0 14 48 c1 e1 04 48 c1 e0 04 48 03 47 10 4c 01 c1 48 8b 50 08 48 8b 00 <48> 89 51 08 48 89 01 41 80 bd d7 00 00 00 00 75 82 48 8b 19 49 8b [ 5511.227091] RSP: 0018:ffffc90000003dd0 EFLAGS: 00010246 [ 5511.233135] RAX: 0000000000000000 RBX: ffff88810c8da600 RCX: 0000000000000000 [ 5511.241384] RDX: 000000000000003c RSI: 0000000000000001 RDI: ffff888115f555c0 [ 5511.249634] RBP: ffffc90000003e08 R08: 0000000000000000 R09: ffff889092296b48 [ 5511.257886] R10: 0000ffffffffffff R11: ffff889092296800 R12: 0000000000000000 [ 5511.266138] R13: ffff88810c8db500 R14: 0000000000000040 R15: 0000000000000100 [ 5511.274387] FS: 0000000000000000(0000) GS:ffff88903f800000(0000) knlGS:0000000000000000 [ 5511.283746] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5511.290389] CR2: 0000000000000008 CR3: 00000001046e2001 CR4: 00000000003706f0 [ 5511.298640] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 5511.306892] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 5511.315142] Call Trace: [ 5511.317972] [ 5511.320301] ice_xmit_zc+0x68/0x2f0 [ice] [ 5511.324977] ? ktime_get+0x38/0xa0 [ 5511.328913] ice_napi_poll+0x7a/0x6a0 [ice] [ 5511.333784] __napi_poll+0x2c/0x160 [ 5511.337821] net_rx_action+0xdd/0x200 [ 5511.342058] __do_softirq+0xe6/0x2dd [ 5511.346198] irq_exit_rcu+0xb5/0x100 [ 5511.350339] common_interrupt+0xa4/0xc0 [ 5511.354777] [ 5511.357201] [ 5511.359625] asm_common_interrupt+0x1e/0x40 [ 5511.364466] RIP: 0010:cpuidle_enter_state+0xd2/0x360 [ 5511.370211] Code: 49 89 c5 0f 1f 44 00 00 31 ff e8 e9 00 7b ff 45 84 ff 74 12 9c 58 f6 c4 02 0f 85 72 02 00 00 31 ff e8 02 0c 80 ff fb 45 85 f6 <0f> 88 11 01 00 00 49 63 c6 4c 2b 2c 24 48 8d 14 40 48 8d 14 90 49 [ 5511.391921] RSP: 0018:ffffffff82a03e60 EFLAGS: 00000202 [ 5511.397962] RAX: ffff88903f800000 RBX: 0000000000000001 RCX: 000000000000001f [ 5511.406214] RDX: 0000000000000000 RSI: ffffffff823400b9 RDI: ffffffff8234c046 [ 5511.424646] RBP: ffff88810a384800 R08: 000005032a28c046 R09: 0000000000000008 [ 5511.443233] R10: 000000000000000b R11: 0000000000000006 R12: ffffffff82bcf700 [ 5511.461922] R13: 000005032a28c046 R14: 0000000000000001 R15: 0000000000000000 [ 5511.480300] cpuidle_enter+0x29/0x40 [ 5511.494329] do_idle+0x1c7/0x250 [ 5511.507610] cpu_startup_entry+0x19/0x20 [ 5511.521394] start_kernel+0x649/0x66e [ 5511.534626] secondary_startup_64_no_verify+0xc3/0xcb [ 5511.549230] Detect such case during bind() and allocate this memory region via newly introduced xp_alloc_tx_descs(). Also, use kvcalloc instead of kcalloc as for other buffer pool allocations, so that it matches the kvfree() from xp_destroy(). Fixes: d1bc532e99be ("i40e: xsk: Move tmp desc array from driver to pool") Signed-off-by: Maciej Fijalkowski Acked-by: Magnus Karlsson --- include/net/xsk_buff_pool.h | 1 + net/xdp/xsk.c | 13 +++++++++++++ net/xdp/xsk_buff_pool.c | 16 ++++++++++++---- 3 files changed, 26 insertions(+), 4 deletions(-) diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h index 5554ee75e7da..647722e847b4 100644 --- a/include/net/xsk_buff_pool.h +++ b/include/net/xsk_buff_pool.h @@ -97,6 +97,7 @@ int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev, u16 queue_id, u16 flags); int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem, struct net_device *dev, u16 queue_id); +int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs); void xp_destroy(struct xsk_buff_pool *pool); void xp_get_pool(struct xsk_buff_pool *pool); bool xp_put_pool(struct xsk_buff_pool *pool); diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 040c73345b7c..57afb96c41e8 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -967,6 +967,19 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) xp_get_pool(umem_xs->pool); xs->pool = umem_xs->pool; + + /* If underlying shared umem was created without Tx + * ring, allocate Tx descs array that Tx batching API + * utilizes + */ + if (xs->tx && !xs->pool->tx_descs) { + err = xp_alloc_tx_descs(xs->pool, xs); + if (err) { + xp_put_pool(xs->pool); + sockfd_put(sock); + goto out_unlock; + } + } } xdp_get_umem(umem_xs->umem); diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c index af040ffa14ff..87bdd71c7bb6 100644 --- a/net/xdp/xsk_buff_pool.c +++ b/net/xdp/xsk_buff_pool.c @@ -42,6 +42,16 @@ void xp_destroy(struct xsk_buff_pool *pool) kvfree(pool); } +int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs) +{ + pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs), + GFP_KERNEL); + if (!pool->tx_descs) + return -ENOMEM; + + return 0; +} + struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, struct xdp_umem *umem) { @@ -59,11 +69,9 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, if (!pool->heads) goto out; - if (xs->tx) { - pool->tx_descs = kcalloc(xs->tx->nentries, sizeof(*pool->tx_descs), GFP_KERNEL); - if (!pool->tx_descs) + if (xs->tx) + if (xp_alloc_tx_descs(pool, xs)) goto out; - } pool->chunk_mask = ~((u64)umem->chunk_size - 1); pool->addrs_cnt = umem->size;