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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 8E632C47404 for ; Mon, 14 Oct 2019 07:03:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D4DC207FF for ; Mon, 14 Oct 2019 07:03:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730183AbfJNHDR (ORCPT ); Mon, 14 Oct 2019 03:03:17 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:3706 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726618AbfJNHDQ (ORCPT ); Mon, 14 Oct 2019 03:03:16 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id B33F869579410FFCB488; Mon, 14 Oct 2019 15:03:13 +0800 (CST) Received: from [127.0.0.1] (10.177.224.82) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.439.0; Mon, 14 Oct 2019 15:03:03 +0800 To: LKML , , Ingo Molnar , Andrew Morton , , , CC: Kefeng Wang , "zhangyi (F)" From: Zhihao Cheng Subject: [QUESTION] Hung task warning while running syzkaller test Message-ID: <0d7aa66d-d2b9-775c-56b3-543d132fdb84@huawei.com> Date: Mon, 14 Oct 2019 15:03:02 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="------------629EEFE2DAB4CD04D145207B" X-Originating-IP: [10.177.224.82] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --------------629EEFE2DAB4CD04D145207B Content-Type: text/plain; charset="gbk" Content-Transfer-Encoding: 7bit Hi, everyone. We met a hung task problem while running syzkaller test. The stacks of hung tasks vary in net/fs/sched, and we provide a stable reproduce test case in fs. The higher the kernel version, the lower the probability of reproduce. Maybe the mainline has gradually optimized the scheduling and mutex. Environment: A. qemu(x86_64 8-core 16GB-RAM) B. physical machine (x86_64 8-core 314GB-RAM) ./syz-execprog -executor=/home/abc/syz-executor -repeat=0 -procs=16 -cover=0 repro repro is a configuration file containing syzkaller execution instructions, which shown as follows: syz_execute_func(&(0x7f0000000140)="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") socket(0x1, 0x80000, 0x4) Hung task in kernel-4.4(See full message in hung_task_verbose.log): [ 420.762345] INFO: task syz-executor.1:8244 blocked for more than 140 seconds. [ 420.763691] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 420.764645] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 420.765931] syz-executor.1 D ffff88040e6efc80 13728 8244 8242 0x00000000 [ 420.767189] ffff88040e6efc80 ffff88040e71c990 ffff880400000000 ffff880077df3d80 [ 420.768497] ffff88040e71bd80 ffff88040e6f0000 0000000000000246 ffff88041f5007c0 [ 420.769800] ffff88040e71bd80 00000000ffffffff ffff88040e6efc98 ffffffff818c6ebc [ 420.771109] Call Trace: [ 420.771540] [] schedule+0x3c/0x90 [ 420.772369] [] schedule_preempt_disabled+0x15/0x20 [ 420.773437] [] mutex_lock_nested+0x182/0x500 [ 420.774421] [] ? walk_component+0x21f/0x310 [ 420.775396] [] ? __inode_permission+0x3a/0x80 [ 420.776391] [] walk_component+0x21f/0x310 [ 420.777333] [] ? path_lookupat+0x1b/0x110 [ 420.778273] [] path_lookupat+0x5d/0x110 [ 420.779197] [] filename_lookup+0xb1/0x180 [ 420.780130] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 420.781211] [] ? kmem_cache_alloc+0x240/0x2b0 [ 420.782212] [] ? debug_lockdep_rcu_enabled+0x1d/0x20 [ 420.783312] [] user_path_at_empty+0x36/0x40 [ 420.784284] [] path_removexattr+0x43/0xb0 [ 420.785229] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 420.786283] [] SyS_lremovexattr+0x10/0x20 [ 420.787232] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 420.788302] 1 lock held by syz-executor.1/8244: [ 420.789051] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 Hung task in kernel-5.3-rc6: [30391.827102] INFO: task syz-executor.6:12211 blocked for more than 143 seconds. [30391.827194] Not tainted 5.3.0-rc6-514.55.6.9.x86_64 #41 [30391.827214] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [30391.827239] syz-executor.6 D13904 12211 12143 0x00000000 [30391.827319] Call Trace: [30391.828583] ? __schedule+0x3cc/0x8b0 [30391.828669] schedule+0x30/0xb0 [30391.828785] rwsem_down_write_slowpath+0x2d2/0x730 [30391.829039] ? filename_create+0x9d/0x1d0 [30391.829110] ? filename_create+0x9d/0x1d0 [30391.829136] ? rwsem_down_write_slowpath+0x5/0x730 [30391.829163] filename_create+0x9d/0x1d0 [30391.829247] do_mkdirat+0x54/0x120 [30391.829361] do_syscall_64+0x85/0x380 [30391.829445] entry_SYSCALL_64_after_hwframe+0x49/0xbe [30391.829509] RIP: 0033:0x20000148 [30391.829562] Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f2 aa 98 44 13 e8 0f 05 <95> 32 05 83 00 00 00 71 f3 2e f3 0f 1b 6f 00 2e 67 66 66 44 0f 38 [30391.829604] RSP: 002b:00007fd154213bd8 EFLAGS: 00000203 ORIG_RAX: 0000000000000053 [30391.829638] RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 0000000020000148 [30391.829659] RDX: da194cf4f57fa1d4 RSI: 0000000000000000 RDI: 00007fd15421460a [30391.829680] RBP: 0000000000000045 R08: 0000000000000005 R09: 0000000000000006 [30391.829703] R10: 0000000000000007 R11: 0000000000000203 R12: 000000000000000b [30391.829724] R13: 000000000000014c R14: 000000000000000d R15: 00000000ffffffff Intro of attachments: hung_task_verbose.log: verbose of hung task(with lockdep) repro: reproduction file which contains syzkaller execution instructions Any ideas or suggestions? Thanks a lot. --------------629EEFE2DAB4CD04D145207B Content-Type: text/plain; charset="UTF-8"; name="hung_task_verbose.log" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="hung_task_verbose.log" [ 420.762345] INFO: task syz-executor.1:8244 blocked for more than 140 seconds. [ 420.763691] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 420.764645] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 420.765931] syz-executor.1 D ffff88040e6efc80 13728 8244 8242 0x00000000 [ 420.767189] ffff88040e6efc80 ffff88040e71c990 ffff880400000000 ffff880077df3d80 [ 420.768497] ffff88040e71bd80 ffff88040e6f0000 0000000000000246 ffff88041f5007c0 [ 420.769800] ffff88040e71bd80 00000000ffffffff ffff88040e6efc98 ffffffff818c6ebc [ 420.771109] Call Trace: [ 420.771540] [] schedule+0x3c/0x90 [ 420.772369] [] schedule_preempt_disabled+0x15/0x20 [ 420.773437] [] mutex_lock_nested+0x182/0x500 [ 420.774421] [] ? walk_component+0x21f/0x310 [ 420.775396] [] ? __inode_permission+0x3a/0x80 [ 420.776391] [] walk_component+0x21f/0x310 [ 420.777333] [] ? path_lookupat+0x1b/0x110 [ 420.778273] [] path_lookupat+0x5d/0x110 [ 420.779197] [] filename_lookup+0xb1/0x180 [ 420.780130] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 420.781211] [] ? kmem_cache_alloc+0x240/0x2b0 [ 420.782212] [] ? debug_lockdep_rcu_enabled+0x1d/0x20 [ 420.783312] [] user_path_at_empty+0x36/0x40 [ 420.784284] [] path_removexattr+0x43/0xb0 [ 420.785229] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 420.786283] [] SyS_lremovexattr+0x10/0x20 [ 420.787232] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 420.788302] 1 lock held by syz-executor.1/8244: [ 420.789051] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 [ 420.790815] INFO: task syz-executor.1:8735 blocked for more than 140 seconds. [ 420.791990] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 420.792901] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 420.794184] syz-executor.1 D ffff88040b047c30 13856 8735 8729 0x00000000 [ 420.795398] ffff88040b047c30 ffff88040b7caad0 ffff880400000000 ffff88040a570000 [ 420.796698] ffff88040b7c9ec0 ffff88040b048000 0000000000000246 ffff88041f5007c0 [ 420.798003] ffff88040b7c9ec0 00000000ffffffff ffff88040b047c48 ffffffff818c6ebc [ 420.799320] Call Trace: [ 420.799731] [] schedule+0x3c/0x90 [ 420.800555] [] schedule_preempt_disabled+0x15/0x20 [ 420.801614] [] mutex_lock_nested+0x182/0x500 [ 420.802603] [] ? walk_component+0x21f/0x310 [ 420.803566] [] ? __inode_permission+0x3a/0x80 [ 420.804556] [] walk_component+0x21f/0x310 [ 420.805493] [] ? path_lookupat+0x1b/0x110 [ 420.806431] [] path_lookupat+0x5d/0x110 [ 420.807349] [] filename_lookup+0xb1/0x180 [ 420.808288] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 420.809364] [] ? kmem_cache_alloc+0x240/0x2b0 [ 420.810353] [] user_path_at_empty+0x36/0x40 [ 420.811331] [] do_utimes+0x115/0x160 [ 420.812202] [] SyS_utime+0x9b/0xd0 [ 420.813034] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 420.814081] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 420.815149] 1 lock held by syz-executor.1/8735: [ 420.815903] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 [ 420.817647] INFO: task syz-executor.1:8795 blocked for more than 140 seconds. [ 420.818828] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 420.819736] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 420.821016] syz-executor.1 D ffff88040ad6fc80 13952 8795 8791 0x00000000 [ 420.822233] ffff88040ad6fc80 ffff88040acc2ad0 ffff880400000000 ffff88040ac30000 [ 420.823539] ffff88040acc1ec0 ffff88040ad70000 0000000000000246 ffff88041f5007c0 [ 420.824840] ffff88040acc1ec0 00000000ffffffff ffff88040ad6fc98 ffffffff818c6ebc [ 420.826138] Call Trace: [ 420.826565] [] schedule+0x3c/0x90 [ 420.827392] [] schedule_preempt_disabled+0x15/0x20 [ 420.828454] [] mutex_lock_nested+0x182/0x500 [ 420.829433] [] ? walk_component+0x21f/0x310 [ 420.830400] [] ? __inode_permission+0x3a/0x80 [ 420.831402] [] walk_component+0x21f/0x310 [ 420.832341] [] ? path_lookupat+0x1b/0x110 [ 420.833278] [] path_lookupat+0x5d/0x110 [ 420.834191] [] filename_lookup+0xb1/0x180 [ 420.835127] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 420.836201] [] ? kmem_cache_alloc+0x240/0x2b0 [ 420.837196] [] ? debug_lockdep_rcu_enabled+0x1d/0x20 [ 420.838287] [] user_path_at_empty+0x36/0x40 [ 420.839261] [] path_removexattr+0x43/0xb0 [ 420.840199] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 420.841246] [] SyS_lremovexattr+0x10/0x20 [ 420.842186] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 420.843256] 1 lock held by syz-executor.1/8795: [ 420.844001] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 [ 420.845766] INFO: task syz-executor.1:9075 blocked for more than 140 seconds. [ 420.846948] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 420.847855] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 420.849136] syz-executor.1 D ffff880409783df0 14176 9075 9073 0x00000000 [ 420.850352] ffff880409783df0 ffff8804094e8c10 ffff880400000000 ffff8803fe8c9ec0 [ 420.851662] ffff8804094e8000 ffff880409784000 0000000000000246 ffff88041f5007c0 [ 420.852962] ffff8804094e8000 00000000ffffffff ffff880409783e08 ffffffff818c6ebc [ 420.854272] Call Trace: [ 420.854691] [] schedule+0x3c/0x90 [ 420.855517] [] schedule_preempt_disabled+0x15/0x20 [ 420.856578] [] mutex_lock_nested+0x182/0x500 [ 420.857555] [] ? filename_create+0x7f/0x170 [ 420.858524] [] ? percpu_down_read+0x5c/0xa0 [ 420.859501] [] filename_create+0x7f/0x170 [ 420.860440] [] SyS_mkdir+0x51/0xe0 [ 420.861279] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 420.862342] 2 locks held by syz-executor.1/9075: [ 420.863109] #0: (sb_writers#2){.+.+.+}, at: [] __sb_start_write+0xb7/0xf0 [ 420.864642] #1: (&sb->s_type->i_mutex_key#2/1){+.+.+.}, at: [] filename_create+0x7f/0x170 [ 431.979231] INFO: task syz-executor.1:9569 blocked for more than 140 seconds. [ 431.980483] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 431.981429] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 431.982754] syz-executor.1 D ffff8804064d7c30 14272 9569 7814 0x00000000 [ 431.983969] ffff8804064d7c30 ffff88040687c990 ffff880400000000 ffff880406c43d80 [ 431.985281] ffff88040687bd80 ffff8804064d8000 0000000000000246 ffff88041f5007c0 [ 431.986596] ffff88040687bd80 00000000ffffffff ffff8804064d7c48 ffffffff818c6ebc [ 431.987898] Call Trace: [ 431.988329] [] schedule+0x3c/0x90 [ 431.989149] [] schedule_preempt_disabled+0x15/0x20 [ 431.990210] [] mutex_lock_nested+0x182/0x500 [ 431.991203] [] ? walk_component+0x21f/0x310 [ 431.992177] [] ? __inode_permission+0x3a/0x80 [ 431.993183] [] walk_component+0x21f/0x310 [ 431.994116] [] ? path_lookupat+0x1b/0x110 [ 431.995064] [] path_lookupat+0x5d/0x110 [ 431.995977] [] filename_lookup+0xb1/0x180 [ 431.996922] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 431.998001] [] ? kmem_cache_alloc+0x240/0x2b0 [ 431.999005] [] user_path_at_empty+0x36/0x40 [ 431.999974] [] do_utimes+0x115/0x160 [ 432.000842] [] SyS_utime+0x9b/0xd0 [ 432.001687] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 432.002751] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 432.003819] 1 lock held by syz-executor.1/9569: [ 432.004577] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 [ 432.006328] INFO: task syz-executor.1:9810 blocked for more than 140 seconds. [ 432.007516] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 432.008428] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 432.009720] syz-executor.1 D ffff88040523bc80 13952 9810 9808 0x00000000 [ 432.010950] ffff88040523bc80 ffff880405230c10 ffff880400000000 ffff880404c43d80 [ 432.012265] ffff880405230000 ffff88040523c000 0000000000000246 ffff88041f5007c0 [ 432.013574] ffff880405230000 00000000ffffffff ffff88040523bc98 ffffffff818c6ebc [ 432.014886] Call Trace: [ 432.015310] [] schedule+0x3c/0x90 [ 432.016131] [] schedule_preempt_disabled+0x15/0x20 [ 432.017195] [] mutex_lock_nested+0x182/0x500 [ 432.018182] [] ? walk_component+0x21f/0x310 [ 432.019149] [] ? __inode_permission+0x3a/0x80 [ 432.020140] [] walk_component+0x21f/0x310 [ 432.021079] [] ? path_lookupat+0x1b/0x110 [ 432.022017] [] path_lookupat+0x5d/0x110 [ 432.022941] [] filename_lookup+0xb1/0x180 [ 432.023880] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 432.024959] [] ? kmem_cache_alloc+0x240/0x2b0 [ 432.025953] [] ? debug_lockdep_rcu_enabled+0x1d/0x20 [ 432.027049] [] user_path_at_empty+0x36/0x40 [ 432.028016] [] path_removexattr+0x43/0xb0 [ 432.028953] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 432.030003] [] SyS_lremovexattr+0x10/0x20 [ 432.030949] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 432.032011] 1 lock held by syz-executor.1/9810: [ 432.032767] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 [ 432.034509] INFO: task syz-executor.1:9826 blocked for more than 140 seconds. [ 432.035690] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 432.036606] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 432.037895] syz-executor.1 D ffff8804053cfc80 13856 9826 9816 0x00000000 [ 432.039113] ffff8804053cfc80 ffff88040539c990 ffff880400000000 ffff88040513dc40 [ 432.040427] ffff88040539bd80 ffff8804053d0000 0000000000000246 ffff88041f5007c0 [ 432.041730] ffff88040539bd80 00000000ffffffff ffff8804053cfc98 ffffffff818c6ebc [ 432.043035] Call Trace: [ 432.043459] [] schedule+0x3c/0x90 [ 432.044287] [] schedule_preempt_disabled+0x15/0x20 [ 432.045355] [] mutex_lock_nested+0x182/0x500 [ 432.046339] [] ? walk_component+0x21f/0x310 [ 432.047343] [] ? __inode_permission+0x3a/0x80 [ 432.048338] [] walk_component+0x21f/0x310 [ 432.049278] [] ? path_lookupat+0x1b/0x110 [ 432.050218] [] path_lookupat+0x5d/0x110 [ 432.051132] [] filename_lookup+0xb1/0x180 [ 432.052071] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 432.053148] [] ? kmem_cache_alloc+0x240/0x2b0 [ 432.054139] [] ? debug_lockdep_rcu_enabled+0x1d/0x20 [ 432.055233] [] user_path_at_empty+0x36/0x40 [ 432.056201] [] path_removexattr+0x43/0xb0 [ 432.057133] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 432.058178] [] SyS_lremovexattr+0x10/0x20 [ 432.059114] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 432.060175] 1 lock held by syz-executor.1/9826: [ 432.060922] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 [ 432.062672] INFO: task syz-executor.1:9902 blocked for more than 140 seconds. [ 432.063852] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 432.064762] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 432.066049] syz-executor.1 D ffff880404417c70 13856 9902 9862 0x00000000 [ 432.067280] ffff880404417c70 ffff880404aec990 ffff880400000000 ffff88040533bd80 [ 432.068587] ffff880404aebd80 ffff880404418000 0000000000000246 ffff88041f5007c0 [ 432.069890] ffff880404aebd80 00000000ffffffff ffff880404417c88 ffffffff818c6ebc [ 432.071243] Call Trace: [ 432.071656] [] schedule+0x3c/0x90 [ 432.072483] [] schedule_preempt_disabled+0x15/0x20 [ 432.073546] [] mutex_lock_nested+0x182/0x500 [ 432.074534] [] ? walk_component+0x21f/0x310 [ 432.075505] [] ? __inode_permission+0x3a/0x80 [ 432.076502] [] walk_component+0x21f/0x310 [ 432.077446] [] ? path_lookupat+0x1b/0x110 [ 432.078391] [] path_lookupat+0x5d/0x110 [ 432.079314] [] filename_lookup+0xb1/0x180 [ 432.080260] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 432.081348] [] ? kmem_cache_alloc+0x240/0x2b0 [ 432.082351] [] user_path_at_empty+0x36/0x40 [ 432.083331] [] path_getxattr+0x4b/0xb0 [ 432.084234] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 432.085291] [] SyS_lgetxattr+0x11/0x20 [ 432.086195] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 432.087273] 1 lock held by syz-executor.1/9902: [ 432.088025] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 [ 445.381195] INFO: task syz-executor.1:9914 blocked for more than 140 seconds. [ 445.382485] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 445.383408] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 445.384705] syz-executor.1 D ffff880404df7c80 13856 9914 9907 0x00000000 [ 445.385931] ffff880404df7c80 ffff880404e18c10 ffff880400000000 ffff8804059d0000 [ 445.387264] ffff880404e18000 ffff880404df8000 0000000000000246 ffff88041f5007c0 [ 445.388582] ffff880404e18000 00000000ffffffff ffff880404df7c98 ffffffff818c6ebc [ 445.389896] Call Trace: [ 445.390327] [] schedule+0x3c/0x90 [ 445.391157] [] schedule_preempt_disabled+0x15/0x20 [ 445.392229] [] mutex_lock_nested+0x182/0x500 [ 445.393226] [] ? walk_component+0x21f/0x310 [ 445.394203] [] ? __inode_permission+0x3a/0x80 [ 445.395219] [] walk_component+0x21f/0x310 [ 445.396157] [] ? path_lookupat+0x1b/0x110 [ 445.397100] [] path_lookupat+0x5d/0x110 [ 445.398017] [] filename_lookup+0xb1/0x180 [ 445.398971] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 445.400059] [] ? kmem_cache_alloc+0x240/0x2b0 [ 445.401060] [] ? debug_lockdep_rcu_enabled+0x1d/0x20 [ 445.402159] [] user_path_at_empty+0x36/0x40 [ 445.403139] [] path_removexattr+0x43/0xb0 [ 445.404085] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 445.405138] [] SyS_lremovexattr+0x10/0x20 [ 445.406081] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 445.407160] 1 lock held by syz-executor.1/9914: [ 445.407932] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 [ 445.409681] INFO: task syz-executor.1:9921 blocked for more than 140 seconds. [ 445.410870] Not tainted 4.4.186-514.55.6.9.x86_64 #1 [ 445.411786] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 445.413080] syz-executor.1 D ffff880404473c30 14208 9921 9902 0x00000000 [ 445.414306] ffff880404473c30 ffff880404b96850 ffff880400000000 ffff880405339ec0 [ 445.415624] ffff880404b95c40 ffff880404474000 0000000000000246 ffff88041f5007c0 [ 445.416934] ffff880404b95c40 00000000ffffffff ffff880404473c48 ffffffff818c6ebc [ 445.418258] Call Trace: [ 445.418681] [] schedule+0x3c/0x90 [ 445.419513] [] schedule_preempt_disabled+0x15/0x20 [ 445.420583] [] mutex_lock_nested+0x182/0x500 [ 445.421569] [] ? walk_component+0x21f/0x310 [ 445.422544] [] ? __inode_permission+0x3a/0x80 [ 445.423548] [] walk_component+0x21f/0x310 [ 445.424498] [] ? path_lookupat+0x1b/0x110 [ 445.425442] [] path_lookupat+0x5d/0x110 [ 445.426360] [] filename_lookup+0xb1/0x180 [ 445.427314] [] ? rcu_read_lock_sched_held+0x6d/0x80 [ 445.428400] [] ? kmem_cache_alloc+0x240/0x2b0 [ 445.429401] [] user_path_at_empty+0x36/0x40 [ 445.430379] [] do_utimes+0x115/0x160 [ 445.431260] [] SyS_utime+0x9b/0xd0 [ 445.432098] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 445.433155] [] entry_SYSCALL_64_fastpath+0x1e/0x9a [ 445.434227] 1 lock held by syz-executor.1/9921: [ 445.434985] #0: (&sb->s_type->i_mutex_key#2){+.+.+.}, at: [] walk_component+0x21f/0x310 --------------629EEFE2DAB4CD04D145207B Content-Type: text/plain; charset="UTF-8"; name="repro" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="repro" syz_execute_func(&(0x7f0000000140)="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") socket(0x1, 0x80000, 0x4) --------------629EEFE2DAB4CD04D145207B--