INFO: task syz-executor.4:20368 blocked for more than 143 seconds. Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:28000 pid:20368 ppid: 8508 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:4269 [inline] __schedule+0x890/0x2030 kernel/sched/core.c:5019 schedule+0xcf/0x270 kernel/sched/core.c:5098 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5157 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x81a/0x1110 kernel/locking/mutex.c:1103 blkdev_put+0x30/0x520 fs/block_dev.c:1795 blkdev_close+0x8c/0xb0 fs/block_dev.c:1844 __fput+0x283/0x920 fs/file_table.c:280 task_work_run+0xdd/0x190 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xb9b/0x29f0 kernel/exit.c:823 do_group_exit+0x125/0x310 kernel/exit.c:920 get_signal+0x3ea/0x1f70 kernel/signal.c:2750 arch_do_signal_or_restart+0x2a6/0x1ea0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:274 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: Unable to access opcode bytes at RIP 0x45de8f. RSP: 002b:00007fbf36db1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffe00 RBX: 0000000000012f00 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 000000000118bf58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007fff971fd40f R14: 00007fbf36db29c0 R15: 000000000118bf2c INFO: task systemd-udevd:20377 blocked for more than 143 seconds. Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:systemd-udevd state:D stack:26488 pid:20377 ppid: 4896 flags:0x00004100 Call Trace: context_switch kernel/sched/core.c:4269 [inline] __schedule+0x890/0x2030 kernel/sched/core.c:5019 schedule+0xcf/0x270 kernel/sched/core.c:5098 io_schedule+0xb5/0x120 kernel/sched/core.c:6792 wait_on_page_bit_common+0x424/0xeb0 mm/filemap.c:1273 wait_on_page_bit mm/filemap.c:1334 [inline] wait_on_page_locked include/linux/pagemap.h:670 [inline] wait_on_page_read mm/filemap.c:3148 [inline] do_read_cache_page+0x957/0x1390 mm/filemap.c:3191 read_mapping_page include/linux/pagemap.h:496 [inline] read_part_sector+0xf6/0x5b0 block/partitions/core.c:780 adfspart_check_ICS+0x9d/0xc90 block/partitions/acorn.c:360 check_partition block/partitions/core.c:140 [inline] blk_add_partitions+0x456/0xe40 block/partitions/core.c:708 bdev_disk_changed+0x288/0x580 fs/block_dev.c:1410 __blkdev_get+0xee4/0x1870 fs/block_dev.c:1539 blkdev_get+0xd1/0x240 fs/block_dev.c:1627 blkdev_open+0x21d/0x2b0 fs/block_dev.c:1744 do_dentry_open+0x4b9/0x11b0 fs/open.c:817 do_open fs/namei.c:3252 [inline] path_openat+0x1b9a/0x2730 fs/namei.c:3369 do_filp_open+0x17e/0x3c0 fs/namei.c:3396 do_sys_openat2+0x16d/0x420 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_sys_open fs/open.c:1192 [inline] __se_sys_open fs/open.c:1188 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1188 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f2425aca840 Code: Unable to access opcode bytes at RIP 0x7f2425aca816. RSP: 002b:00007ffcfafb06a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000055bed5dd1520 RCX: 00007f2425aca840 RDX: 000055bed5d57fe3 RSI: 00000000000a0800 RDI: 000055bed5dd13e0 RBP: 00007ffcfafb0820 R08: 000055bed5d57670 R09: 0000000000000010 R10: 000055bed5d57d0c R11: 0000000000000246 R12: 00007ffcfafb0770 R13: 000055bed5dd04d0 R14: 0000000000000003 R15: 000000000000000e Showing all locks held in the system: 1 lock held by khungtaskd/1655: #0: ffffffff8b339ca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6252 1 lock held by in:imklog/8179: #0: ffff8880118920f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932 1 lock held by syz-executor.4/20368: #0: ffff888016386880 (&bdev->bd_mutex){+.+.}-{3:3}, at: blkdev_put+0x30/0x520 fs/block_dev.c:1795 1 lock held by systemd-udevd/20377: #0: ffff888016386880 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x457/0x1870 fs/block_dev.c:1472 1 lock held by syz-executor.4/20702: #0: ffff888016386880 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x457/0x1870 fs/block_dev.c:1472 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1655 Comm: khungtaskd Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:338 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4882 Comm: systemd-journal Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_memory_region+0x16/0x180 mm/kasan/generic.c:192 Code: 02 0f 1f 00 48 89 f2 be f8 00 00 00 e9 e3 9d 23 02 0f 1f 00 48 85 f6 0f 84 70 01 00 00 49 89 f9 41 54 44 0f b6 c2 49 01 f1 55 <53> 0f 82 18 01 00 00 48 b8 ff ff ff ff ff 7f ff ff 48 39 c7 0f 86 RSP: 0018:ffffc9000163fa80 EFLAGS: 00000082 RAX: 0000000000000000 RBX: ffffffff8b2a8950 RCX: ffffffff81594a7c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8b3145f0 RBP: ffffffff8b3145f0 R08: 0000000000000000 R09: ffffffff8b3145f8 R10: fffff520002c7f8c R11: 0000000000000000 R12: ffffc9000163fc50 R13: 00000000fffff10e R14: 000000000000110e R15: 0000000000000002 FS: 00007f538240f8c0(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f537f951000 CR3: 0000000018201000 CR4: 00000000001526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline] atomic_long_read include/asm-generic/atomic-long.h:29 [inline] desc_read+0x21c/0x330 kernel/printk/printk_ringbuffer.c:528 desc_read_finalized_seq+0x81/0x1c0 kernel/printk/printk_ringbuffer.c:1754 prb_read kernel/printk/printk_ringbuffer.c:1802 [inline] _prb_read_valid+0x1a1/0x6d0 kernel/printk/printk_ringbuffer.c:1882 prb_read_valid+0x75/0xa0 kernel/printk/printk_ringbuffer.c:1931 devkmsg_read+0x13f/0x740 kernel/printk/printk.c:770 vfs_read+0x1b5/0x570 fs/read_write.c:494 ksys_read+0x12d/0x250 fs/read_write.c:634 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f538199f210 Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 RSP: 002b:00007ffe61824748 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007ffe618271c0 RCX: 00007f538199f210 RDX: 0000000000002000 RSI: 00007ffe61824fc0 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000008 R09: 00007ffe6188a0f0 R10: 0000000000021dae R11: 0000000000000246 R12: 00007ffe61824fc0 R13: 00007ffe61827118 R14: 000055e317e65958 R15: 0005b4858247cfa3