syzbot has found a reproducer for the following issue on: HEAD commit: bf682942cd26 Merge tag 'scsi-fixes' of git://git.kernel.or.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12096640880000 kernel config: https://syzkaller.appspot.com/x/.config?x=7db7ad17eb14cb7 dashboard link: https://syzkaller.appspot.com/bug?extid=0e9dc403e57033a74b1d compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=116e80ff080000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11bfbbcf080000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+0e9dc403e57033a74b1d@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task udevd:3638 blocked for more than 143 seconds. Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:26248 pid: 3638 ppid: 2972 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 io_schedule+0xba/0x130 kernel/sched/core.c:8714 folio_wait_bit_common+0x3dd/0xa90 mm/filemap.c:1298 __folio_lock mm/filemap.c:1664 [inline] folio_lock include/linux/pagemap.h:939 [inline] folio_lock include/linux/pagemap.h:935 [inline] __filemap_get_folio+0xc6d/0xed0 mm/filemap.c:1936 truncate_inode_pages_range+0x37c/0x1510 mm/truncate.c:378 kill_bdev block/bdev.c:75 [inline] blkdev_flush_mapping+0x140/0x2f0 block/bdev.c:661 blkdev_put_whole+0xd1/0xf0 block/bdev.c:692 blkdev_put+0x226/0x770 block/bdev.c:952 blkdev_close+0x64/0x80 block/fops.c:499 __fput+0x277/0x9d0 fs/file_table.c:320 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad5/0x29b0 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x238c/0x2610 kernel/signal.c:2857 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fea11178697 RSP: 002b:00007ffc3c7fb710 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: 0000000000000008 RBX: 000055b3e78469c0 RCX: 00007fea11178697 RDX: 00000000000a0800 RSI: 000055b3e7818920 RDI: 00000000ffffff9c RBP: 000055b3e7818920 R08: 0000000000000001 R09: 00007ffc3c816080 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800 R13: 000055b3e7819a80 R14: 00007ffc3c7fb7bc R15: 000055b3e780b2c0 </TASK> INFO: task syz-executor127:3645 blocked for more than 143 seconds. Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor127 state:D stack:28376 pid: 3645 ppid: 3635 flags:0x00000004 Call Trace: <TASK> context_switch kernel/sched/core.c:5182 [inline] __schedule+0xadf/0x52b0 kernel/sched/core.c:6494 schedule+0xda/0x1b0 kernel/sched/core.c:6570 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6629 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa44/0x1350 kernel/locking/mutex.c:747 blkdev_get_by_dev.part.0+0x9b/0xb90 block/bdev.c:812 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:855 blkdev_open+0x13c/0x2c0 block/fops.c:485 do_dentry_open+0x4a4/0x13a0 fs/open.c:880 do_open fs/namei.c:3557 [inline] path_openat+0x1c92/0x28f0 fs/namei.c:3691 do_filp_open+0x1b6/0x400 fs/namei.c:3718 do_sys_openat2+0x16d/0x4c0 fs/open.c:1313 do_sys_open fs/open.c:1329 [inline] __do_sys_openat fs/open.c:1345 [inline] __se_sys_openat fs/open.c:1340 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1340 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ff1e173a4d7 RSP: 002b:00007ffdf8c863c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff1e173a4d7 RDX: 0000000000000000 RSI: 00007ffdf8c86440 RDI: 00000000ffffff9c RBP: 00007ffdf8c86440 R08: 000000000000ffff R09: 00007ffdf8c862d0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 </TASK> Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8bf85db0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8bf85ab0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8bf86900 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6492 1 lock held by klogd/2961: #0: ffff8880b9a3a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:544 2 locks held by getty/3287: #0: ffff88801caa6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc90001c482f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef0/0x13e0 drivers/tty/n_tty.c:2177 1 lock held by udevd/3638: #0: ffff88801e6644c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xbc/0x770 block/bdev.c:910 1 lock held by syz-executor127/3645: #0: ffff88801e6644c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb90 block/bdev.c:812 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x46/0x14f lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x206/0x250 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xc18/0xf50 kernel/hung_task.c:369 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 41 Comm: kworker/u4:2 Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:check_wait_context kernel/locking/lockdep.c:4741 [inline] RIP: 0010:__lock_acquire+0x574/0x56d0 kernel/locking/lockdep.c:5003 Code: 00 00 45 89 fe 41 83 ee 01 0f 88 7c 13 00 00 49 b9 00 00 00 00 00 fc ff df 49 63 c6 48 8d 04 80 49 8d ac c5 99 0a 00 00 eb 12 <41> 83 ee 01 48 83 ed 28 41 83 fe ff 0f 84 15 0b 00 00 48 8d 5d df RSP: 0018:ffffc90000d2f738 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8880174d0af8 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff908e8dd9 RBP: ffff8880174d0b19 R08: 0000000000000000 R09: dffffc0000000000 R10: fffffbfff211c32a R11: 0000000000000000 R12: ffff8880174d0bc0 R13: ffff8880174d0080 R14: 0000000000000000 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056317ad90680 CR3: 000000000bc8e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:349 [inline] __get_locked_pte+0x154/0x270 mm/memory.c:1838 get_locked_pte include/linux/mm.h:2089 [inline] __text_poke+0x1b3/0x8e0 arch/x86/kernel/alternative.c:1123 text_poke arch/x86/kernel/alternative.c:1208 [inline] text_poke_bp_batch+0x147/0x6c0 arch/x86/kernel/alternative.c:1487 text_poke_flush arch/x86/kernel/alternative.c:1660 [inline] text_poke_flush arch/x86/kernel/alternative.c:1657 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1667 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:801 static_key_disable_cpuslocked+0x152/0x1b0 kernel/jump_label.c:207 static_key_disable+0x16/0x20 kernel/jump_label.c:215 toggle_allocation_gate mm/kfence/core.c:825 [inline] toggle_allocation_gate+0x183/0x390 mm/kfence/core.c:803 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.080 msecs
