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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 5B4BFC43441 for ; Wed, 14 Nov 2018 09:03:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1557F214F1 for ; Wed, 14 Nov 2018 09:03:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IMOswsu1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1557F214F1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com 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 S1732253AbeKNTGG (ORCPT ); Wed, 14 Nov 2018 14:06:06 -0500 Received: from mail-it1-f196.google.com ([209.85.166.196]:36076 "EHLO mail-it1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727595AbeKNTGG (ORCPT ); Wed, 14 Nov 2018 14:06:06 -0500 Received: by mail-it1-f196.google.com with SMTP id w7-v6so22798070itd.1 for ; Wed, 14 Nov 2018 01:03:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to:cc; bh=OQ63Dkph1ZeurRFVKrW9Du5IqPOwtlYuQhEv39Dp/HU=; b=IMOswsu1qRqtjz2/sMiHTljbRR/3dhz7V5m0F9vaBWyr0FNBvfVLga1t8Uivk22Sim tYTwqVm6Typ1L0EVScnHQ4AxqySqCJw+S5h04zRF9IaQNzzAEq4S1asY3X5dpsVtehNo UzMndbG9OX75Icqo71Syf1I48sexj+HP013tcGemk9N24eY7qkTdVsu1qeXRnnLJ6uTJ /u7HBMTk+J5dbvETj2gJC/q7PU1WtBBBG2te1efOak5HrXzFEWD5SMixcAdR7uMxldm+ WPRvW93ICUmz/YGephanGn3+rubAQuUSR9E+MFom22z1dnNrGlc5KQKrtt92w3XgChb6 W/3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=OQ63Dkph1ZeurRFVKrW9Du5IqPOwtlYuQhEv39Dp/HU=; b=XuwTw8erOiY+rO1YXDdWsbw4Uo4TfGicKiULuOBKQ1QQWSClZMD+wTuEaPXek1DIH/ eSEHC6yxH/ifNCkqS0a4C9SEYYqCT5bXQKF+NR4kofLsKkdz6QN9lbo/fxy7F0YjUDK7 uaJZ9uBSCr054JHaXCs5+3hTudZGqDMzGuwElLXIWcGmN9X/41kdS9Q+/FQqzfwB7ZSc CM2ObONcTJSdoIJ2GLxS9L5YKBuu/4r6ubfbAe4LKSgqOR8oJTKcZf+q4FrZcAzh7ACO a7clw5xFq2D6tFS3blSANR5s/PVgcluFmtnDt0jSCNVQrjj8xk3T8IGTDBExvIP95G+E QSLw== X-Gm-Message-State: AGRZ1gIR+Fn6OW9muk1uSmv2aVYj//xcwLPYrQdro39ENw2SPlrX50Zh qYhz4t4pNdjxasaX0YcUasEry6yiFUVDpyNmqWg= X-Google-Smtp-Source: AJdET5czPMMTfOKTBlqSY/NmdsrFGZLV7cEH02qxtlYq4l7uuLunKiZUPhRurPoPr8UA06WOnWdnVuf024AKOCI+4iw= X-Received: by 2002:a02:8a69:: with SMTP id e38mr892272jal.81.1542186224705; Wed, 14 Nov 2018 01:03:44 -0800 (PST) MIME-Version: 1.0 From: Kyungtae Kim Date: Wed, 14 Nov 2018 04:03:33 -0500 Message-ID: Subject: KMSAN: uninit-value in rcu_accelerate_cbs / KMSAN: uninit-value in rcu_process_callbacks To: paulmck@linux.vnet.ibm.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com Cc: Byoungyoung Lee , DaeRyong Jeong , syzkaller@googlegroups.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We report two crashes in v4.19-rc8 (4.20-rc1 as well, I guess): (Unfortunately, there is no repro for those.) The two crashes seem to share the same issue. In both cases, (uninitialized) memory access violation occurs when "rdp->cblist" is about to be accessed (kernel/rcu/tree.c:2838,1728). I guess those are freed before the use, but I still haven't figured out the reason why. I'm looking forward to some help. Crash log 1 ========================================= BUG: KMSAN: uninit-value in __rcu_process_callbacks kernel/rcu/tree.c:2838 [inline] BUG: KMSAN: uninit-value in rcu_process_callbacks+0x5ac/0x1cb0 kernel/rcu/tree.c:2864 CPU: 0 PID: 20 Comm: kauditd Not tainted 4.19.0-rc8+ #18 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x305/0x460 lib/dump_stack.c:113 kmsan_report+0x1a2/0x2e0 mm/kmsan/kmsan.c:917 __msan_warning+0x7d/0xe0 mm/kmsan/kmsan_instr.c:500 __rcu_process_callbacks kernel/rcu/tree.c:2838 [inline] rcu_process_callbacks+0x5ac/0x1cb0 kernel/rcu/tree.c:2864 __do_softirq+0x5ff/0xa55 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x22d/0x270 kernel/softirq.c:414 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:536 smp_apic_timer_interrupt+0x64/0x90 arch/x86/kernel/apic/apic.c:1059 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:869 RIP: 0010:finish_lock_switch+0x2b/0x40 kernel/sched/core.c:2578 Code: 48 89 e5 53 48 89 fb e8 e3 43 9a 00 8b b8 88 0c 00 00 48 8b 00 48 85 c0 75 12 48 89 df e8 7d 38 9a 00 c6 00 00 c6 03 00 fb 5b <5d> c3 e8 de 42 9a 00 eb e7 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 RSP: 0018:ffff88010622fca0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: ffff8801105bcc40 RBX: ffff8801061554c0 RCX: ffff8801105bdc40 RDX: ffff8801105bdc40 RSI: aaaaaaaaaaaab000 RDI: ffffea00077ec560 RBP: ffff88010622fca0 R08: ffffffff7fffffff R09: 0000000000000002 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800751cb880 R13: 0000000000000000 R14: ffff880106155db8 R15: ffff88013fcb9c40 finish_task_switch+0xe3/0x270 kernel/sched/core.c:2679 context_switch kernel/sched/core.c:2832 [inline] __schedule+0x78f/0x8f0 kernel/sched/core.c:3479 schedule+0x1cc/0x300 kernel/sched/core.c:3523 kauditd_thread+0xc64/0xee0 kernel/audit.c:889 kthread+0x5b1/0x5f0 kernel/kthread.c:247 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:416 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:255 [inline] kmsan_internal_alloc_meta_for_pages+0x157/0x730 mm/kmsan/kmsan.c:693 kmsan_alloc_page+0x80/0xe0 mm/kmsan/kmsan_hooks.c:320 __alloc_pages_nodemask+0x128c/0x69b0 mm/page_alloc.c:4416 alloc_pages_current+0x51f/0x760 mm/mempolicy.c:2093 alloc_pages include/linux/gfp.h:511 [inline] alloc_slab_page mm/slub.c:1459 [inline] allocate_slab mm/slub.c:1604 [inline] new_slab+0x552/0x1f30 mm/slub.c:1675 new_slab_objects mm/slub.c:2438 [inline] ___slab_alloc+0x1414/0x1dd0 mm/slub.c:2590 __slab_alloc mm/slub.c:2630 [inline] slab_alloc_node mm/slub.c:2693 [inline] slab_alloc mm/slub.c:2735 [inline] kmem_cache_alloc+0xc9b/0xda0 mm/slub.c:2740 kmem_cache_zalloc include/linux/slab.h:697 [inline] avc_alloc_node+0x109/0xb90 security/selinux/avc.c:572 avc_update_node+0x172/0x1ee0 security/selinux/avc.c:859 avc_denied+0x312/0x360 security/selinux/avc.c:1024 avc_has_perm_noaudit+0x733/0x770 security/selinux/avc.c:1155 avc_has_perm+0x172/0x480 security/selinux/avc.c:1184 sock_has_perm security/selinux/hooks.c:4539 [inline] selinux_socket_sendmsg+0x297/0x360 security/selinux/hooks.c:4875 security_socket_sendmsg+0x127/0x200 security/security.c:1410 sock_sendmsg net/socket.c:628 [inline] ___sys_sendmsg+0xd5f/0x1290 net/socket.c:2116 __sys_sendmsg net/socket.c:2154 [inline] __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg+0x307/0x460 net/socket.c:2161 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 ========================================================= Crash log 2 ========================================================= BUG: KMSAN: uninit-value in rcu_accelerate_cbs+0x821/0x990 kernel/rcu/tree.c:1728 CPU: 0 PID: 10 Comm: rcu_sched Not tainted 4.19.0-rc8+ #18 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x305/0x460 lib/dump_stack.c:113 kmsan_report+0x1a2/0x2e0 mm/kmsan/kmsan.c:917 __msan_warning+0x7d/0xe0 mm/kmsan/kmsan_instr.c:500 rcu_accelerate_cbs+0x821/0x990 kernel/rcu/tree.c:1728 __note_gp_changes+0x2ac/0x9e0 kernel/rcu/tree.c:1807 rcu_gp_cleanup kernel/rcu/tree.c:2109 [inline] rcu_gp_kthread+0x3019/0x3990 kernel/rcu/tree.c:2236 kthread+0x5b1/0x5f0 kernel/kthread.c:247 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:416 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:255 [inline] kmsan_internal_alloc_meta_for_pages+0x157/0x730 mm/kmsan/kmsan.c:693 kmsan_alloc_page+0x80/0xe0 mm/kmsan/kmsan_hooks.c:320 __alloc_pages_nodemask+0x128c/0x69b0 mm/page_alloc.c:4416 alloc_pages_current+0x51f/0x760 mm/mempolicy.c:2093 alloc_pages include/linux/gfp.h:511 [inline] alloc_slab_page mm/slub.c:1459 [inline] allocate_slab mm/slub.c:1604 [inline] new_slab+0x552/0x1f30 mm/slub.c:1675 new_slab_objects mm/slub.c:2438 [inline] ___slab_alloc+0x1414/0x1dd0 mm/slub.c:2590 __slab_alloc mm/slub.c:2630 [inline] slab_alloc_node mm/slub.c:2693 [inline] slab_alloc mm/slub.c:2735 [inline] kmem_cache_alloc+0xc9b/0xda0 mm/slub.c:2740 kmem_cache_zalloc include/linux/slab.h:697 [inline] avc_alloc_node+0x109/0xb90 security/selinux/avc.c:572 avc_insert security/selinux/avc.c:696 [inline] avc_compute_av+0x31e/0x1050 security/selinux/avc.c:1008 avc_has_perm_noaudit+0x516/0x770 security/selinux/avc.c:1149 avc_has_perm+0x172/0x480 security/selinux/avc.c:1184 selinux_socket_create+0x248/0x3c0 security/selinux/hooks.c:4560 security_socket_create+0x146/0x210 security/security.c:1372 __sock_create+0x26b/0xf30 net/socket.c:1232 sock_create net/socket.c:1317 [inline] __sys_socket+0x180/0x670 net/socket.c:1347 __do_sys_socket net/socket.c:1356 [inline] __se_sys_socket+0x8d/0xb0 net/socket.c:1354 __x64_sys_socket+0x4a/0x70 net/socket.c:1354 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 ========================================================= Thanks, Kyungtae Kim