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=-5.7 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_PASS autolearn=unavailable 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 5663BC43381 for ; Tue, 26 Feb 2019 06:50:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 280D9213A2 for ; Tue, 26 Feb 2019 06:50:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726267AbfBZGuL (ORCPT ); Tue, 26 Feb 2019 01:50:11 -0500 Received: from mail-io1-f70.google.com ([209.85.166.70]:39678 "EHLO mail-io1-f70.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id 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X-Received: by 2002:a02:3941:: with SMTP id w1mr9916044jae.7.1551163805266; Mon, 25 Feb 2019 22:50:05 -0800 (PST) Date: Mon, 25 Feb 2019 22:50:05 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000009a01370582c6772a@google.com> Subject: INFO: rcu detected stall in ext4_file_write_iter From: syzbot To: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tytso@mit.edu Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 8a61716ff2ab Merge tag 'ceph-for-5.0-rc8' of git://github... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=161b71d4c00000 kernel config: https://syzkaller.appspot.com/x/.config?x=7132344728e7ec3f dashboard link: https://syzkaller.appspot.com/bug?extid=7d19c5fe6a3f1161abb7 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=103908f8c00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=105e5cd0c00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+7d19c5fe6a3f1161abb7@syzkaller.appspotmail.com audit: type=1400 audit(1550814986.750:36): avc: denied { map } for pid=8058 comm="syz-executor004" path="/root/syz-executor004991115" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 hrtimer: interrupt took 42841 ns rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=5873, q=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295059997-4295049495), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor004 R running task 26448 8069 8060 0x00000000 Call Trace: sched_show_task kernel/sched/core.c:5306 [inline] sched_show_task.cold+0x292/0x30b kernel/sched/core.c:5281 print_other_cpu_stall kernel/rcu/tree.c:1301 [inline] check_cpu_stall kernel/rcu/tree.c:1429 [inline] rcu_pending kernel/rcu/tree.c:3018 [inline] rcu_check_callbacks.cold+0xa10/0xa4a kernel/rcu/tree.c:2521 update_process_times+0x32/0x80 kernel/time/timer.c:1635 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:94 Code: e5 08 41 bc f4 ff ff ff e8 11 9f ea ff 48 c7 05 12 fb e5 08 00 00 00 00 e9 c8 e9 ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 38 0c RSP: 0018:ffff888084ed72c0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffff88809a2205c0 RCX: ffffffff81e7c36c RDX: 1ffff11013444114 RSI: ffffffff81e7c37a RDI: ffff88809a2208a0 RBP: ffff888084ed7300 R08: ffff88808fa28240 R09: ffffed1015d25bd0 R10: ffffed1015d25bcf R11: ffff8880ae92de7b R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 __ext4_journal_start fs/ext4/ext4_jbd2.h:311 [inline] ext4_dirty_inode+0x64/0xc0 fs/ext4/inode.c:6081 __mark_inode_dirty+0x919/0x1290 fs/fs-writeback.c:2155 mark_inode_dirty include/linux/fs.h:2125 [inline] __generic_write_end+0x1b9/0x240 fs/buffer.c:2118 generic_write_end+0x6c/0x90 fs/buffer.c:2163 ext4_da_write_end+0x3c8/0xa50 fs/ext4/inode.c:3204 generic_perform_write+0x2f0/0x530 mm/filemap.c:3219 __generic_file_write_iter+0x25e/0x630 mm/filemap.c:3333 ext4_file_write_iter+0x33f/0x1160 fs/ext4/file.c:266 call_write_iter include/linux/fs.h:1863 [inline] do_iter_readv_writev+0x5e0/0x8e0 fs/read_write.c:680 do_iter_write fs/read_write.c:956 [inline] do_iter_write+0x184/0x610 fs/read_write.c:937 vfs_iter_write+0x77/0xb0 fs/read_write.c:969 iter_file_splice_write+0x667/0xbe0 fs/splice.c:749 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x126/0x1a0 fs/splice.c:1023 splice_direct_to_actor+0x369/0x970 fs/splice.c:978 do_splice_direct+0x1da/0x2a0 fs/splice.c:1066 do_sendfile+0x597/0xd00 fs/read_write.c:1436 __do_sys_sendfile64 fs/read_write.c:1491 [inline] __se_sys_sendfile64 fs/read_write.c:1483 [inline] __x64_sys_sendfile64+0x15a/0x220 fs/read_write.c:1483 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x446a59 Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fce454e5db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000446a59 RDX: 0000000020000000 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080fffffffe R11: 0000000000000246 R12: 00000000006dcc2c R13: 00007ffd7bf04daf R14: 00007fce454e69c0 R15: 20c49ba5e353f7cf rcu: rcu_preempt kthread starved for 10502 jiffies! g5873 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29200 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2844 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3485 schedule+0x92/0x180 kernel/sched/core.c:3529 schedule_timeout+0x4db/0xfd0 kernel/time/timer.c:1803 rcu_gp_fqs_loop kernel/rcu/tree.c:1948 [inline] rcu_gp_kthread+0x956/0x17a0 kernel/rcu/tree.c:2105 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 --- This bug is generated by a bot. 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