INFO: task udevd:16745 blocked for more than 122 seconds. Not tainted 6.12.30-syzkaller-g94ce385c22d5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:0 pid:16745 tgid:16745 ppid:109 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5924 [inline] __schedule+0x145b/0x1f10 kernel/sched/core.c:7750 __schedule_loop kernel/sched/core.c:7831 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7846 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270 bdev_open+0xd5/0xd60 block/bdev.c:909 blkdev_open+0x3d1/0x560 block/fops.c:627 do_dentry_open+0x97b/0x1510 fs/open.c:960 vfs_open+0x86/0x230 fs/open.c:1090 do_open fs/namei.c:3774 [inline] path_openat+0x2b6c/0x34b0 fs/namei.c:3933 do_filp_open+0x1c6/0x3e0 fs/namei.c:3960 do_sys_openat2+0x12c/0x1c0 fs/open.c:1438 do_sys_open fs/open.c:1453 [inline] __do_sys_openat fs/open.c:1469 [inline] __se_sys_openat fs/open.c:1464 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1464 x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fe4768a7407 RSP: 002b:00007ffd3d8d8910 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe476f8f880 RCX: 00007fe4768a7407 RDX: 00000000000a0800 RSI: 0000563de73cffe0 RDI: ffffffffffffff9c RBP: 0000563de718f2c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000563de73e1d80 R13: 0000563de73d4990 R14: 0000000000000000 R15: 0000563de73e1d80 INFO: task syz.2.6688:20438 blocked for more than 123 seconds. Not tainted 6.12.30-syzkaller-g94ce385c22d5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.6688 state:D stack:0 pid:20438 tgid:20436 ppid:17131 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5924 [inline] __schedule+0x145b/0x1f10 kernel/sched/core.c:7750 __schedule_loop kernel/sched/core.c:7831 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7846 io_schedule+0x89/0xe0 kernel/sched/core.c:8658 folio_wait_bit_common+0x6ae/0x910 mm/filemap.c:1336 folio_put_wait_locked mm/filemap.c:1500 [inline] do_read_cache_folio+0x14d/0x4d0 mm/filemap.c:3880 read_cache_folio+0x54/0x90 mm/filemap.c:3930 read_mapping_folio include/linux/pagemap.h:1019 [inline] read_part_sector+0xcc/0x250 block/partitions/core.c:716 msdos_partition+0x118/0x3000 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+0x81c/0x1610 block/partitions/core.c:687 loop_reread_partitions+0x64/0x110 drivers/block/loop.c:464 loop_configure+0xfd8/0x1320 drivers/block/loop.c:1071 lo_ioctl+0x76c/0x20a0 drivers/block/loop.c:-1 blkdev_ioctl+0x549/0x680 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0x135/0x1b0 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:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f9fad18e929 RSP: 002b:00007f9fae008038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9fad3b6080 RCX: 00007f9fad18e929 RDX: 00002000000002c0 RSI: 0000000000004c0a RDI: 0000000000000004 RBP: 00007f9fad210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9fad3b6080 R15: 00007ffcfd0d6448 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.30-syzkaller-g94ce385c22d5 #0 16e511e29439c8b2668c1520ec6e7e54ef5e5f6a Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/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:229 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:385 kthread+0x2ca/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 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 6.12.30-syzkaller-g94ce385c22d5 #0 16e511e29439c8b2668c1520ec6e7e54ef5e5f6a Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0x17/0x20 arch/x86/kernel/paravirt.c:106 Code: cc cc cc b8 ad d0 4f 36 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 dc 41 00 f3 0f 1e fa 55 48 89 e5 fb f4 <5d> e9 c3 59 02 00 cc cc cc b8 00 00 00 00 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff87207da0 EFLAGS: 000002c6 RAX: ffff8881f6e00000 RBX: ffffffff87215540 RCX: ffffffff8585700e RDX: 0000000000000001 RSI: 0000000000000004 RDI: 000000000078021c RBP: ffffffff87207da0 R08: ffff8881f6e39733 R09: 1ffff1103edc72e6 R10: dffffc0000000000 R11: ffffed103edc72e7 R12: 1ffffffff0e42aa8 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff87ca6ee8 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd03292fc8 CR3: 00000001217f4000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000004800 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline] default_idle+0x17/0x30 arch/x86/kernel/process.c:748 arch_cpu_idle+0xd/0x20 arch/x86/kernel/process.c:785 default_idle_call+0x3f/0x80 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1a0/0x470 kernel/sched/idle.c:326 cpu_startup_entry+0x48/0x70 kernel/sched/idle.c:424 rest_init+0x10b/0x130 init/main.c:748 start_kernel+0x46a/0x4bb init/main.c:1135 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