INFO: task syz-executor.2:19980 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29680 19980 8145 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309 block nbd0: Device being setup by another task call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 __get_super.part.0+0x209/0x2e0 fs/super.c:698 overlayfs: conflicting lowerdir path __get_super include/linux/spinlock.h:329 [inline] get_super+0x2b/0x50 fs/super.c:727 fsync_bdev+0x14/0xc0 fs/block_dev.c:483 blkdev_flushbuf block/ioctl.c:436 [inline] blkdev_ioctl+0x912/0x1a80 block/ioctl.c:521 blktrace: Concurrent blktraces are not allowed on nbd4 block_ioctl+0xe9/0x130 fs/block_dev.c:1906 blktrace: Concurrent blktraces are not allowed on nbd4 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f3a78c8f639 Code: Bad RIP value. RSP: 002b:00007f3a771e1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f3a78db0050 RCX: 00007f3a78c8f639 RDX: 0000000000000000 RSI: 0000000000001261 RDI: 0000000000000003 RBP: 00007f3a78ceaae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffff0dc06cf R14: 00007f3a771e1300 R15: 0000000000022000 Showing all locks held in the system: 3 locks held by kworker/u4:0/7: blktrace: Concurrent blktraces are not allowed on nbd4 1 lock held by khungtaskd/1568: #0: 000000002f84d961 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 3 locks held by systemd-udevd/4697: 1 lock held by in:imklog/7801: #0: 00000000944c3f54 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by agetty/7772: #0: 00000000baf3ee8d (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000cca90699 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 drivers/tty/n_tty.c:2154 2 locks held by kworker/1:3/8468: #0: 000000006537409c ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 0000000025a4b6b3 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 2 locks held by kworker/u4:9/13832: 2 locks held by syz-executor.0/16615: #0: 00000000a33c4e7a (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x1d0/0x1480 fs/block_dev.c:1478 #1: 00000000371444d5 (loop_ctl_mutex){+.+.}, at: lo_open+0x19/0xd0 drivers/block/loop.c:1771 2 locks held by syz-executor.2/19967: 1 lock held by syz-executor.2/19980: #0: 0000000061b51f3c (&type->s_umount_key#58){++++}, at: __get_super.part.0+0x209/0x2e0 fs/super.c:698 2 locks held by syz-executor.2/20301: #0: 000000008f115cde (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x90/0x3b0 fs/super.c:1125 #1: 0000000061b51f3c (&type->s_umount_key#58){++++}, at: grab_super+0xa2/0x350 fs/super.c:383 1 lock held by syz-executor.2/20302: #0: 0000000061b51f3c (&type->s_umount_key#58){++++}, at: __get_super.part.0+0x209/0x2e0 fs/super.c:698 1 lock held by syz-executor.5/22703: #0: 000000002dea42a6 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #0: 000000002dea42a6 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x4dc/0x6f0 kernel/rcu/tree_exp.h:667 2 locks held by syz-executor.2/22718: #0: 00000000371444d5 (loop_ctl_mutex){+.+.}, at: loop_control_ioctl+0x7b/0x480 drivers/block/loop.c:2137 #1: 000000002dea42a6 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #1: 000000002dea42a6 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x256/0x6f0 kernel/rcu/tree_exp.h:667 1 lock held by systemd-udevd/22721: #0: 00000000a33c4e7a (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x1d0/0x1480 fs/block_dev.c:1478 3 locks held by syz-executor.4/22725: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1568 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7804 Comm: rs:main Q:Reg Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:101 Code: 90 90 90 90 90 90 90 90 48 8b 34 24 65 48 8b 04 25 c0 df 01 00 65 8b 15 cc 59 9f 7e 81 e2 00 01 1f 00 75 2b 8b 90 60 13 00 00 <83> fa 02 75 20 48 8b 88 68 13 00 00 8b 80 64 13 00 00 48 8b 11 48 RSP: 0018:ffff888092447540 EFLAGS: 00000246 RAX: ffff8880a98bc000 RBX: 000000003ab860fc RCX: ffffffff813110c1 RDX: 0000000000000000 RSI: ffffffff813110e6 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88809848387e R14: dffffc0000000000 R15: 0000000000000002 FS: 00007fe9b9670700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb659134000 CR3: 00000000af50a000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: crc32c_intel_le_hw_byte arch/x86/crypto/crc32c-intel_glue.c:66 [inline] crc32c_intel_le_hw arch/x86/crypto/crc32c-intel_glue.c:90 [inline] crc32c_pcl_intel_update+0x136/0x320 arch/x86/crypto/crc32c-intel_glue.c:185