INFO: task syz.0.924:8325 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.924 state:D stack:26656 pid:8325 tgid:8322 ppid:5614 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5584 [inline] __schedule+0x1b47/0x5b40 kernel/sched/core.c:7387 __schedule_loop kernel/sched/core.c:7464 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7479 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7536 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821 bdev_open+0xde/0xd70 block/bdev.c:990 blkdev_open+0x461/0x600 block/fops.c:696 do_dentry_open+0x80e/0x1360 fs/open.c:1000 vfs_open_consume+0x4a/0x350 fs/open.c:1131 do_open fs/namei.c:4875 [inline] path_openat+0x14a6/0x1da0 fs/namei.c:5040 do_file_open+0x23e/0x4a0 fs/namei.c:5069 do_sys_openat2+0x115/0x200 fs/open.c:1442 do_sys_open fs/open.c:1448 [inline] __do_sys_openat fs/open.c:1464 [inline] __se_sys_openat fs/open.c:1459 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1459 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f20e815e9ce RSP: 002b:00007f20e63f5b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f20e63f66c0 RCX: 00007f20e815e9ce RDX: 0000000000001000 RSI: 00007f20e63f5c00 RDI: ffffffffffffff9c RBP: 00007f20e63f5c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f20e8426038 R14: 00007f20e8425fa0 R15: 00007ffff75e9268 Showing all locks held in the system: locks held by kworker/u8:1/13: 3, last CPU#1: #0: ffff888031c14948 ((wq_completion)bat_events){+.+.}-{0:0}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:678 #1: ffff8880b87247c8 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933 #2: ffffffff8ed5a260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8ed5a260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8ed5a260 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #2: ffffffff8ed5a260 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 locks held by khungtaskd/33: 1, last CPU#0: #0: ffffffff8ed5a260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5a260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5a260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u8:7/158: 4, on CPU#0: #0: ffff8880206ff148 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff8880206ff148 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff8880206ff148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff8880206ff148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc90002ea7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90002ea7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90002ea7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc90002ea7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff8880343ee0e8 (&type->s_umount_key#34){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:670 #3: ffff8880343ecc98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1f1/0x4e0 fs/ext4/inode.c:3031 locks held by getty/5365: 2, on CPU#1: #0: ffff88803484b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor/5597: 3, on CPU#1: #0: ffff8880738ab948 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309 #1: ffff8880343ee558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff8880343ee558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898 #2: ffff8880343ea938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by udevd/5619: 1, on CPU#1: #0: ffff888026ca8350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990 locks held by syz.0.924/8325: 1, on CPU#1: #0: ffff888026ca8350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990 locks held by syz.4.1224/9130: 3, on CPU#0: #0: ffff8880570dda88 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309 #1: ffff8880343ee558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff8880343ee558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1fd/0x12c0 fs/ext4/inode.c:6898 #2: ffff8880343ea938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by syz.1.1232/9153: 3, on CPU#0: #0: ffff888025ceccc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:548 [inline] #0: ffff888025ceccc0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579 #1: ffff8880343ee460 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2279 [inline] #1: ffff8880343ee460 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:901 #2: ffff8880343ea938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 locks held by syz.3.1233/9154: 3, on CPU#0: #0: ffff888077a9f180 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:548 [inline] #0: ffff888077a9f180 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579 #1: ffff8880343ee460 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2279 [inline] #1: ffff8880343ee460 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:901 #2: ffff8880343ea938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fb0/0x21f0 fs/jbd2/transaction.c:444 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 33 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline] watchdog+0x1073/0x10f0 kernel/hung_task.c:598 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 3b 85 02 e9 03 18 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 29 1e 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc900001c7e40 EFLAGS: 00000242 RAX: 00000000000c429d RBX: ffffffff819c2f50 RCX: 8000000000000001 RDX: 0000000000000001 RSI: ffffffff8e43b49c RDI: ffffffff8c6df580 RBP: ffffc900001c7f10 R08: ffff8880b8733e5b R09: 1ffff110170e67cb R10: dffffc0000000000 R11: ffffed10170e67cc R12: 0000000000000000 R13: 1ffff11003cd83e8 R14: 1ffff92000038fd0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888124dc1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558a515d8168 CR3: 000000000eb48000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:767 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:768 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x2e0/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x157