From patchwork Mon Sep 9 18:15:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pooja Trivedi X-Patchwork-Id: 1159901 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="g8agOywF"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46RxD211NQz9s00 for ; Tue, 10 Sep 2019 04:15:29 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729238AbfIISP2 (ORCPT ); Mon, 9 Sep 2019 14:15:28 -0400 Received: from mail-vs1-f65.google.com ([209.85.217.65]:37972 "EHLO mail-vs1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728883AbfIISP2 (ORCPT ); Mon, 9 Sep 2019 14:15:28 -0400 Received: by mail-vs1-f65.google.com with SMTP id b123so9414118vsb.5 for ; Mon, 09 Sep 2019 11:15:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=9KnYd8hUsQjMlnfx0oKNiSQxGQXVvwoHZS+cy9f4814=; b=g8agOywFwfG7ySIaH9FqiBPvG1Win15F61+M86FhRzwu2Lj64GFVnz47MtSGmBojPo weOVgOR3lg8+KfnuITLjB1RNEmd+2fBtT6NltkAFURDsHU0WtXu0SrLOsVgNkEJpSOv6 ACcfzUXoc/DOeiZF0UaRz723lgCWgzj0eD+yzc/+H4SZV/2IdvWo2cVSUSDv/TVj5Zym 04tocen6UIRJS6Ky7m79WaGiKKPcYMFkcvddWBt+h8nD65JnRxLosTN26DWPVmRkH2Kj 2s6kOStEHux01fhoNd5kHbbiWeV9jdRTLKVKc50UyCEmx0Vvcrvucmh7yvNITgCY6tok jgzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=9KnYd8hUsQjMlnfx0oKNiSQxGQXVvwoHZS+cy9f4814=; b=A+hBLRJ0dFjDOQQWAT5ZtUgdZY4kQLGTWefUZSNW6rfJwXqC4y7OszrB9TNBjak0iZ ZnDP/adlf+TG6HO8PmXOOUddSufH4Kt/nLJXpENCyk2vkz5Xd/gTlJpI/nWLGXFTShuM wtTnjbWownzyJArgdZYgOtCg6KWAWtIZSEe9SZqTorGqiUnxTQ/UeSx6hpz8DfU4KMJo YLODSupOKFWapblqgJD1qvtMk4GcjQmzAQ9NqeHEsYv8swlnGjcILhCRYJSezJjLtiy6 udIcwb9IayPazB0Xn0jW3UOgMF5GabkXfndjlRwLM69Lgge1hzJmQ3+CVXZE+87Wild9 0YrA== X-Gm-Message-State: APjAAAULasFEaOAKll0tYLgl6nxlifK/NnGKhO1M3B2G3oNhqSr8lftY BgPxon1SiRJomIfbvEDFAiXmGFJNZrKQY/fwgT9uRCNQ X-Google-Smtp-Source: APXvYqwE0MIkfV2RCBhVyqmMGioT0Ki20XLVn9SlXaruay9ybmeuwY7kRuAsUYX0K5/NFid/cOToVtUohF0RjCztyAY= X-Received: by 2002:a67:f6c8:: with SMTP id v8mr2535762vso.22.1568052926534; Mon, 09 Sep 2019 11:15:26 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Pooja Trivedi Date: Mon, 9 Sep 2019 14:15:15 -0400 Message-ID: Subject: [PATCH net 1/1] net/tls(TLS_SW): Fix list_del double free caused by a race condition in tls_tx_records To: netdev@vger.kernel.org Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Enclosing tls_tx_records within lock_sock/release_sock pair to ensure write-synchronization is not sufficient because socket lock gets released under memory pressure situation by sk_wait_event while it sleeps waiting for memory, allowing another writer into tls_tx_records. This causes a race condition with record deletion post transmission. To fix this bug, use a flag set in tx_bitmask field of TLS context to ensure single writer in tls_tx_records at a time The bug resulted in the following crash: [ 270.888952] ------------[ cut here ]------------ [ 270.890450] list_del corruption, ffff91cc3753a800->prev is LIST_POISON2 (dead000000000122) [ 270.891194] WARNING: CPU: 1 PID: 7387 at lib/list_debug.c:50 __list_del_entry_valid+0x62/0x90 [ 270.892037] Modules linked in: n5pf(OE) netconsole tls(OE) bonding intel_rapl_msr intel_rapl_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm iTCO_wdt iTCO_vendor_support irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd mei_me cryptd glue_helper ipmi_si sg mei lpc_ich pcspkr joydev ioatdma i2c_i801 ipmi_devintf ipmi_msghandler wmi ip_tables xfs libcrc32c sd_mod mgag200 drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm isci libsas ahci scsi_transport_sas libahci crc32c_intel serio_raw igb libata ptp pps_core dca i2c_algo_bit dm_mirror dm_region_hash dm_log dm_mod [last unloaded: nitrox_drv] [ 270.896836] CPU: 1 PID: 7387 Comm: uperf Kdump: loaded Tainted: G OE 5.3.0-rc4 #1 [ 270.897711] Hardware name: Supermicro SYS-1027R-N3RF/X9DRW, BIOS 3.0c 03/24/2014 [ 270.898597] RIP: 0010:__list_del_entry_valid+0x62/0x90 [ 270.899478] Code: 00 00 00 c3 48 89 fe 48 89 c2 48 c7 c7 e0 f9 ee 8d e8 b2 cf c8 ff 0f 0b 31 c0 c3 48 89 fe 48 c7 c7 18 fa ee 8d e8 9e cf c8 ff <0f> 0b 31 c0 c3 48 89 f2 48 89 fe 48 c7 c7 50 fa ee 8d e8 87 cf c8 [ 270.901321] RSP: 0018:ffffb6ea86eb7c20 EFLAGS: 00010282 [ 270.902240] RAX: 0000000000000000 RBX: ffff91cc3753c000 RCX: 0000000000000000 [ 270.903157] RDX: ffff91bc3f867080 RSI: ffff91bc3f857738 RDI: ffff91bc3f857738 [ 270.904074] RBP: ffff91bc36020940 R08: 0000000000000560 R09: 0000000000000000 [ 270.904988] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 270.905902] R13: ffff91cc3753a800 R14: ffff91cc37cc6400 R15: ffff91cc3753a800 [ 270.906809] FS: 00007f454a88d700(0000) GS:ffff91bc3f840000(0000) knlGS:0000000000000000 [ 270.907715] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 270.908606] CR2: 00007f453c00292c CR3: 000000103554e003 CR4: 00000000001606e0 [ 270.909490] Call Trace: [ 270.910373] tls_tx_records+0x138/0x1c0 [tls] [ 270.911262] tls_sw_sendpage+0x3e0/0x420 [tls] [ 270.912154] inet_sendpage+0x52/0x90 [ 270.913045] ? direct_splice_actor+0x40/0x40 [ 270.913941] kernel_sendpage+0x1a/0x30 [ 270.914831] sock_sendpage+0x20/0x30 [ 270.915714] pipe_to_sendpage+0x62/0x90 [ 270.916592] __splice_from_pipe+0x80/0x180 [ 270.917461] ? direct_splice_actor+0x40/0x40 [ 270.918334] splice_from_pipe+0x5d/0x90 [ 270.919208] direct_splice_actor+0x35/0x40 [ 270.920086] splice_direct_to_actor+0x103/0x230 [ 270.920966] ? generic_pipe_buf_nosteal+0x10/0x10 [ 270.921850] do_splice_direct+0x9a/0xd0 [ 270.922733] do_sendfile+0x1c9/0x3d0 [ 270.923612] __x64_sys_sendfile64+0x5c/0xc0 Signed-off-by: Pooja Trivedi ---------- diff --git a/include/net/tls.h b/include/net/tls.h index 41b2d41..f346a54 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -161,6 +161,7 @@ struct tls_sw_context_tx { #define BIT_TX_SCHEDULED 0 #define BIT_TX_CLOSING 1 +#define BIT_TX_IN_PROGRESS 2 unsigned long tx_bitmask; }; diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 91d21b0..6e99c61 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -367,6 +367,10 @@ int tls_tx_records(struct sock *sk, int flags) struct sk_msg *msg_en; int tx_flags, rc = 0; + /* If another writer is already in tls_tx_records, backoff and leave */ + if (test_and_set_bit(BIT_TX_IN_PROGRESS, &ctx->tx_bitmask)) + return 0; + if (tls_is_partially_sent_record(tls_ctx)) { rec = list_first_entry(&ctx->tx_list, struct tls_rec, list); @@ -415,6 +419,9 @@ int tls_tx_records(struct sock *sk, int flags) if (rc < 0 && rc != -EAGAIN) tls_err_abort(sk, EBADMSG); + /* clear the bit so another writer can get into tls_tx_records */ + clear_bit(BIT_TX_IN_PROGRESS, &ctx->tx_bitmask); + return rc; }