INFO: task systemd:1 blocked for more than 143 seconds. Not tainted 5.8.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd D23248 1 0 0x00000000 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 rwsem_down_read_slowpath+0x2f7/0xc90 kernel/locking/rwsem.c:1099 __down_read kernel/locking/rwsem.c:1341 [inline] down_read+0x1eb/0x420 kernel/locking/rwsem.c:1494 m_start+0x48/0x240 fs/namespace.c:1288 seq_read+0x232/0x1070 fs/seq_file.c:203 __vfs_read+0x76/0x100 fs/read_write.c:426 vfs_read+0x1f6/0x420 fs/read_write.c:462 ksys_read+0x12d/0x250 fs/read_write.c:588 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f2532e0492d Code: Bad RIP value. RSP: 002b:00007ffe5e9c6aa0 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000556dfc83b5a0 RCX: 00007f2532e0492d RDX: 0000000000000400 RSI: 0000556dfc836240 RDI: 0000000000000013 RBP: 0000000000000d68 R08: 00007f25330c2f58 R09: 0000000000000410 R10: 0000556dfc7737d0 R11: 0000000000000293 R12: 00007f25330bf440 R13: 00007f25330be900 R14: 0000000000000000 R15: 0000556dfc837df0 INFO: task syz-executor.1:1776 blocked for more than 144 seconds. Not tainted 5.8.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27776 1776 6998 0x00000004 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 rwsem_down_write_slowpath+0x603/0xc60 kernel/locking/rwsem.c:1235 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 inode_lock include/linux/fs.h:799 [inline] lock_mount+0x8a/0x2e0 fs/namespace.c:2192 do_loopback fs/namespace.c:2349 [inline] do_mount+0xd95/0x1fb0 fs/namespace.c:3193 __do_sys_mount fs/namespace.c:3409 [inline] __se_sys_mount fs/namespace.c:3386 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3386 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb29 Code: Bad RIP value. RSP: 002b:00007fb48906fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00000000004f7520 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000020000000 RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000d800 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000077a R14: 00000000004ca72b R15: 00007fb4890706d4 INFO: task syz-executor.1:1784 blocked for more than 145 seconds. Not tainted 5.8.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29120 1784 6998 0x00004004 Call Trace: context_switch kernel/sched/core.c:3453 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178 schedule+0xd0/0x2a0 kernel/sched/core.c:4253 rwsem_down_write_slowpath+0x603/0xc60 kernel/locking/rwsem.c:1235 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 inode_lock include/linux/fs.h:799 [inline] lock_mount+0x8a/0x2e0 fs/namespace.c:2192 do_loopback fs/namespace.c:2349 [inline] do_mount+0xd95/0x1fb0 fs/namespace.c:3193 __do_sys_mount fs/namespace.c:3409 [inline] __se_sys_mount fs/namespace.c:3386 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3386 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb29 Code: Bad RIP value. RSP: 002b:00007fb48904ec78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00000000004f7520 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000020000000 RBP: 000000000078c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000005890 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000077a R14: 00000000004ca72b R15: 00007fb48904f6d4 Showing all locks held in the system: 2 locks held by systemd/1: #0: ffff88803927eec0 (&p->lock){+.+.}-{3:3}, at: seq_read+0x61/0x1070 fs/seq_file.c:155 #1: ffffffff89c99b30 (namespace_sem){++++}-{3:3}, at: m_start+0x48/0x240 fs/namespace.c:1288 1 lock held by khungtaskd/1146: #0: ffffffff89bc1180 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 4 locks held by khugepaged/1153: 1 lock held by systemd-journal/3873: 1 lock held by in:imklog/6506: #0: ffff8880a87e1b30 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 4 locks held by rs:main Q:Reg/6507: 3 locks held by syz-fuzzer/6839: 3 locks held by syz-executor.1/1773: 1 lock held by syz-executor.1/1776: #0: ffff88804bc9a588 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline] #0: ffff88804bc9a588 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: lock_mount+0x8a/0x2e0 fs/namespace.c:2192 1 lock held by syz-executor.1/1784: #0: ffff88804bc9a588 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline] #0: ffff88804bc9a588 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: lock_mount+0x8a/0x2e0 fs/namespace.c:2192 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1146 Comm: khungtaskd Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd7d/0x1000 kernel/hung_task.c:295 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10055 Comm: kworker/u4:13 Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker RIP: 0010:update_avg kernel/sched/sched.h:200 [inline] RIP: 0010:select_idle_cpu kernel/sched/fair.c:6145 [inline] RIP: 0010:select_idle_sibling kernel/sched/fair.c:6261 [inline] RIP: 0010:select_task_rq_fair+0x21d2/0x2be0 kernel/sched/fair.c:6707 Code: 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 da 05 00 00 48 8b 0c 24 48 8b 41 60 48 89 04 24 48 8b 44 24 50 48 03 04 24 <48> 29 c5 48 8d 45 07 48 0f 49 c5 48 c1 f8 03 48 03 04 24 48 89 41 RSP: 0000:ffffc90001e47ba0 EFLAGS: 00000012 RAX: 0000010786719f2c RBX: 0000000000000001 RCX: ffff8880a96ed800 RDX: 1ffff110152ddb0c RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000010786719e23 R08: ffffffff8be6e058 R09: ffffffff8be6e04f R10: ffffffff8be6e057 R11: 0000000000000001 R12: dffffc0000000000 R13: ffff8880ae720dd8 R14: 0000000000035e00 R15: 0000000000000040 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000003028fc10 CR3: 0000000094694000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: select_task_rq kernel/sched/core.c:2097 [inline] try_to_wake_up+0x3f5/0x1360 kernel/sched/core.c:2653 wake_up_worker kernel/workqueue.c:837 [inline] process_one_work+0x764/0x1670 kernel/workqueue.c:2232 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293