INFO: task udevd:340 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:0 pid:340 tgid:340 ppid:110 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7893 __schedule_loop kernel/sched/core.c:7974 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7989 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 bdev_open+0xd5/0xd60 block/bdev.c:926 blkdev_open+0x3d1/0x560 block/fops.c:627 do_dentry_open+0x978/0x1510 fs/open.c:960 vfs_open+0x86/0x240 fs/open.c:1092 do_open fs/namei.c:3782 [inline] path_openat+0x2bb1/0x34f0 fs/namei.c:3941 do_filp_open+0x1f5/0x440 fs/namei.c:3968 do_sys_openat2+0x134/0x1d0 fs/open.c:1440 do_sys_open fs/open.c:1455 [inline] __do_sys_openat fs/open.c:1471 [inline] __se_sys_openat fs/open.c:1466 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1466 x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f1c600a7407 RSP: 002b:00007fff5661ec30 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f1c607f0880 RCX: 00007f1c600a7407 RDX: 00000000000a0800 RSI: 00005611bf857c70 RDI: ffffffffffffff9c RBP: 00005611bf6192c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005611bf869b90 R13: 00005611bf85a0f0 R14: 0000000000000000 R15: 00005611bf869b90 INFO: task syz.0.353:1544 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.353 state:D stack:0 pid:1544 tgid:1543 ppid:295 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7893 __schedule_loop kernel/sched/core.c:7974 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7989 io_schedule+0x88/0xe0 kernel/sched/core.c:8803 folio_wait_bit_common+0x6d8/0x950 mm/filemap.c:1356 folio_put_wait_locked mm/filemap.c:1520 [inline] do_read_cache_folio+0x14d/0x4c0 mm/filemap.c:4051 read_cache_folio+0x54/0x90 mm/filemap.c:4101 read_mapping_folio include/linux/pagemap.h:1021 [inline] read_part_sector+0xcc/0x250 block/partitions/core.c:716 msdos_partition+0x116/0x2fd0 block/partitions/msdos.c:592 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:583 [inline] bdev_disk_changed+0x822/0x1610 block/partitions/core.c:687 loop_reread_partitions+0x64/0x110 drivers/block/loop.c:467 loop_configure+0x1068/0x13a0 drivers/block/loop.c:1078 lo_ioctl+0xa8b/0x2070 drivers/block/loop.c:1520 blkdev_ioctl+0x548/0x690 block/ioctl.c:699 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0x132/0x1b0 fs/ioctl.c:893 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:893 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f1e5b39ce59 RSP: 002b:00007f1e5c337028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1e5b615fa0 RCX: 00007f1e5b39ce59 RDX: 0000200000000140 RSI: 0000000000004c0a RDI: 0000000000000007 RBP: 00007f1e5b432d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1e5b616038 R14: 00007f1e5b615fa0 R15: 00007ffd235214e8 INFO: task poweroff:1546 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:poweroff state:D stack:0 pid:1546 tgid:1546 ppid:95 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7893 __schedule_loop kernel/sched/core.c:7974 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7989 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 sync_bdevs+0x1af/0x350 block/bdev.c:1269 ksys_sync+0xc6/0x170 fs/sync.c:106 __ia32_sys_sync+0x12/0x20 fs/sync.c:114 x64_sys_call+0x2a58/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:163 do_syscall_x64 arch/x86/entry/common.c:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f93e0cb2f37 RSP: 002b:00007ffcb0f2e9b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f93e0cb2f37 RDX: ffffffffffffff88 RSI: 00007f93e0e4be51 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcb0f2eb18 R14: 00007f93e0ea1000 R15: 00005605befbcd98 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 8a9cd2cbe126bd9938f6e7ac5eb01541012e42ba Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xdad/0xf00 kernel/hung_task.c:423 kthread+0x2c9/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 8a9cd2cbe126bd9938f6e7ac5eb01541012e42ba Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:update_sd_lb_stats kernel/sched/fair.c:-1 [inline] RIP: 0010:sched_balance_find_src_group kernel/sched/fair.c:11632 [inline] RIP: 0010:sched_balance_rq+0x21da/0x4ce0 kernel/sched/fair.c:12079 Code: 40 74 0b c7 84 24 20 04 00 00 02 00 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 6c ec 7f 00 48 83 3b 00 75 5e <48> 8b 9c 24 e8 03 00 00 b8 b8 0c 00 00 48 01 c3 48 89 d8 48 c1 e8 RSP: 0018:ffffc90000007820 EFLAGS: 00000246 RAX: 1ffff1102034d900 RBX: ffff888101a6c800 RCX: ffffffff8160596e RDX: 0000000000000018 RSI: ffffc90000007a60 RDI: ffffc90000007b10 RBP: ffffc90000007cd0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000420 R13: dffffc0000000000 R14: ffff888101a6c83c R15: ffff888103a74480 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555564eb07d0 CR3: 0000000107ecc000 CR4: 00000000003526b0 DR0: 000a000000000000 DR1: ffffffffff7fff00 DR2: 0000000080000001 DR3: fffffffffffffff6 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: sched_balance_domains+0x477/0x9c0 kernel/sched/fair.c:12549 _nohz_idle_balance+0x3fb/0x5c0 kernel/sched/fair.c:13000 nohz_idle_balance kernel/sched/fair.c:13043 [inline] sched_balance_softirq+0x8a/0x170 kernel/sched/fair.c:13273 handle_softirqs+0x1aa/0x630 kernel/softirq.c:621 __do_softirq kernel/softirq.c:659 [inline] invoke_softirq kernel/softirq.c:476 [inline] __irq_exit_rcu+0x47/0xb0 kernel/softirq.c:708 irq_exit_rcu+0xd/0x30 kernel/softirq.c:720 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0x7f/0x90 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1f/0x30 arch/x86/include/asm/idtentry.h:709 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:106 Code: cc cc cc cc cc cc cc b8 5a da d4 19 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 3f 3f 00 55 48 89 e5 fb f4 <5d> c3 cc cc cc cc cc cc cc cc cc cc cc b8 00 00 00 00 90 90 90 90 RSP: 0018:ffffffff87407da0 EFLAGS: 000002c6 RAX: ffff8881f6e00000 RBX: ffffffff874156c0 RCX: ffffffff85a81bcd RDX: 0000000000000001 RSI: 0000000000000004 RDI: 00000000004e4f84 RBP: ffffffff87407da0 R08: ffff8881f6e395eb R09: 1ffff1103edc72bd R10: dffffc0000000000 R11: ffffed103edc72be R12: 1ffffffff0e82ad8 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff87ed30e8 arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline] default_idle+0x17/0x30 arch/x86/kernel/process.c:754 arch_cpu_idle+0xd/0x20 arch/x86/kernel/process.c:791 default_idle_call+0x3e/0x80 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1a1/0x560 kernel/sched/idle.c:335 cpu_startup_entry+0x47/0x60 kernel/sched/idle.c:433 rest_init+0x10b/0x130 init/main.c:760 start_kernel+0x462/0x4bb init/main.c:1242 x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x6a/0x7b arch/x86/kernel/head64.c:488 common_startup_64+0x13b/0x157