INFO: task udevd:349 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:349 tgid:349 ppid:110 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5996 [inline] __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843 __schedule_loop kernel/sched/core.c:7924 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7939 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7996 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 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+0x97b/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: 0033:0x7fe8fbdca407 RSP: 002b:00007ffda210ad00 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe8fbd3e880 RCX: 00007fe8fbdca407 RDX: 00000000000a0800 RSI: 00005648f3961700 RDI: ffffffffffffff9c RBP: 00005648f395e2c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005648f3b93a80 R13: 00005648f3b9f0f0 R14: 0000000000000000 R15: 00005648f3b93a80 INFO: task syz.3.3709:11369 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3709 state:D stack:0 pid:11369 tgid:11368 ppid:6959 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5996 [inline] __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843 __schedule_loop kernel/sched/core.c:7924 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7939 io_schedule+0x88/0xe0 kernel/sched/core.c:8753 folio_wait_bit_common+0x6d8/0x950 mm/filemap.c:1355 folio_put_wait_locked mm/filemap.c:1519 [inline] do_read_cache_folio+0x14d/0x4c0 mm/filemap.c:4042 read_cache_folio+0x54/0x90 mm/filemap.c:4092 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+0x825/0x1610 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+0x54b/0x690 block/ioctl.c:699 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:47 [inline] do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7ff1bf99c629 RSP: 002b:00007ff1c085c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff1bfc15fa0 RCX: 00007ff1bf99c629 RDX: 0000200000000280 RSI: 0000000000004c0a RDI: 0000000000000003 RBP: 00007ff1bfa32b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff1bfc16038 R14: 00007ff1bfc15fa0 R15: 00007ffcd8263c78 INFO: task syz.0.3859:11796 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.3859 state:D stack:0 pid:11796 tgid:11795 ppid:6168 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5996 [inline] __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843 __schedule_loop kernel/sched/core.c:7924 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7939 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7996 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 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: 0033:0x7fef6379c629 RSP: 002b:00007fef621f7028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fef63a15fa0 RCX: 00007fef6379c629 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fef63a15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef63a16038 R14: 00007fef63a15fa0 R15: 00007fff2ada2148 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 73dd41fee924560e78783f72ff837ca22365b77d Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 14825 Comm: syz.1.4841 Not tainted syzkaller #0 73dd41fee924560e78783f72ff837ca22365b77d Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:arch_stack_walk+0x13f/0x170 arch/x86/kernel/stacktrace.c:24 Code: 4d 89 f3 41 ba 3a c7 f0 cd 45 03 53 f1 74 02 0f 0b 2e e8 88 e0 c1 1e 84 c0 74 11 4c 89 ff e8 d8 96 06 00 83 bd 78 ff ff ff 00 <75> c1 65 48 8b 04 25 28 00 00 00 48 3b 45 d8 75 12 48 83 c4 68 5b RSP: 0018:ffffc900027a6da8 EFLAGS: 00000002 RAX: 00000000027a6d01 RBX: ffffc900027a6e60 RCX: 00000000027a6d01 RDX: ffffc900027a7f48 RSI: 1ffff920004f4db6 RDI: ffffc900027a6e00 RBP: ffffc900027a6e30 R08: ffffc900027a6e70 R09: ffffc900027a6e68 R10: 0000000000000010 R11: ffffffff8175cbd0 R12: ffff888114c35f00 R13: 0000000000000001 R14: ffffffff8175cbd0 R15: ffffc900027a6da8 FS: 00007f67d51e76c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555656e74e8 CR3: 0000000127592000 CR4: 00000000003526b0 Call Trace: stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:49 __kasan_record_aux_stack+0xb2/0xd0 mm/kasan/generic.c:541 kasan_record_aux_stack_noalloc+0xf/0x20 mm/kasan/generic.c:551 irq_work_queue_on+0xea/0x210 kernel/irq_work.c:150 tell_cpu_to_push+0x5bc/0x660 kernel/sched/rt.c:2423 pull_rt_task kernel/sched/rt.c:2489 [inline] balance_rt+0x2a0/0x440 kernel/sched/rt.c:1741 prev_balance kernel/sched/core.c:6628 [inline] __pick_next_task kernel/sched/core.c:6670 [inline] pick_next_task kernel/sched/core.c:7176 [inline] __schedule+0x964/0x1ea0 kernel/sched/core.c:7769 __schedule_loop kernel/sched/core.c:7924 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7939 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596 unix_wait_for_peer+0x1f6/0x300 net/unix/af_unix.c:1540 unix_dgram_sendmsg+0x1173/0x1ac0 net/unix/af_unix.c:2142 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0xa8c/0xae0 net/socket.c:2610 ___sys_sendmsg+0x2a6/0x370 net/socket.c:2664 __sys_sendmmsg+0x2b4/0x4e0 net/socket.c:2750 __do_sys_sendmmsg net/socket.c:2779 [inline] __se_sys_sendmmsg net/socket.c:2776 [inline] __x64_sys_sendmmsg+0xa4/0xc0 net/socket.c:2776 x64_sys_call+0xfec/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:308 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: 0033:0x7f67d439c629 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f67d51e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f67d4615fa0 RCX: 00007f67d439c629 RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000007 RBP: 00007f67d4432b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f67d4616038 R14: 00007f67d4615fa0 R15: 00007ffdcdaa26d8