INFO: task udevd:15015 blocked in I/O wait for more than 163 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:25256 pid:15015 tgid:15015 ppid:4982   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5521 [inline]
 __schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272
 __schedule_loop kernel/sched/core.c:7349 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7364
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8192
 folio_wait_bit_common+0x836/0xbc0 mm/filemap.c:1329
 folio_put_wait_locked mm/filemap.c:1498 [inline]
 do_read_cache_folio+0x1ac/0x590 mm/filemap.c:4138
 read_mapping_folio include/linux/pagemap.h:1015 [inline]
 read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
 adfspart_check_POWERTEC+0x9a/0x7a0 block/partitions/acorn.c:451
 check_partition block/partitions/core.c:143 [inline]
 blk_add_partitions block/partitions/core.c:591 [inline]
 bdev_disk_changed+0x851/0x17a0 block/partitions/core.c:695
 blkdev_get_whole+0x372/0x510 block/bdev.c:793
 bdev_open+0x324/0xd70 block/bdev.c:1002
 blkdev_open+0x461/0x600 block/fops.c:674
 do_dentry_open+0x816/0x1380 fs/open.c:996
 vfs_open+0x3b/0x340 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x1443/0x1d60 fs/namei.c:5000
 do_file_open+0x23e/0x4a0 fs/namei.c:5029
 do_sys_openat2+0x115/0x200 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1434
 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: 0033:0x7f2efcea7407
RSP: 002b:00007ffcc40ffc50 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2efd57f880 RCX: 00007f2efcea7407
RDX: 00000000000a0800 RSI: 000055ee3f7fc360 RDI: ffffffffffffff9c
RBP: 000055ee3f7fb910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055ee3f83fac0
R13: 000055ee3f809190 R14: 0000000000000000 R15: 000055ee3f83fac0
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/31: 1, last CPU#0:
 #0: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by getty/5370: 2, on CPU#1:
 #0: ffff8880360160a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by udevd/14893: 4, on CPU#1:
 #0: ffff8880814cc758 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0 fs/seq_file.c:183
 #1: ffff8880595cb080 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165
 #2: ffff88803f7593c8 (kn->active#29){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff88803f7593c8 (kn->active#29){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166
 #3: ffff88801e6831d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1109 [inline]
 #3: ffff88801e6831d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by udevd/15002: 4, on CPU#0:
 #0: ffff88805a835bd8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0 fs/seq_file.c:183
 #1: ffff88807f97c080 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165
 #2: ffff888076e3df08 (kn->active#29){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff888076e3df08 (kn->active#29){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166
 #3: ffff88807cc631d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1109 [inline]
 #3: ffff88807cc631d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by udevd/15015: 1, on CPU#0:
 #0: ffff888026a42350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by kworker/0:6/15562: 5, on CPU#0:
 #0: ffff888022eca540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888022eca540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888022eca540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888022eca540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90005577c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90005577c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90005577c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90005577c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffff888029ecd1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #2: ffff888029ecd1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912
 #3: ffff88807cc631d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #3: ffff88807cc631d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
 #4: ffff88802b55f1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #4: ffff88802b55f1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
locks held by kworker/1:4/16032: 7, last CPU#1:
 #0: ffff888022eca540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888022eca540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888022eca540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888022eca540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000359fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000359fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000359fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000359fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffff888029b7a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #2: ffff888029b7a1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912
 #3: ffff88801e6831d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #3: ffff88801e6831d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
 #4: ffff88807a99a1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #4: ffff88807a99a1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
 #5: ffff88807b21e890 (&domain->mutex){+.+.}-{4:4}, at: irq_create_mapping_affinity+0x88/0x1a0 kernel/irq/irqdomain.c:836
 #6: ffff8880344ddb80 (&dev->domain_data.irq_lock){+.+.}-{4:4}, at: chip_bus_lock kernel/irq/internals.h:176 [inline]
 #6: ffff8880344ddb80 (&dev->domain_data.irq_lock){+.+.}-{4:4}, at: __irq_get_desc_lock+0x183/0x1b0 kernel/irq/irqdesc.c:959
locks held by syz.9.6872/29827: 1, on CPU#0:
 #0: ffffffff902504c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff902504c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7138
locks held by syz.2.6874/29831: 1, last CPU#0:
 #0: ffffffff902504c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline]
 #0: ffffffff902504c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3587
locks held by syz.5.6881/29853: 6, last CPU#1:
 #0: ffff888029337678 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:619 [inline]
 #0: ffff888029337678 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:441 [inline]
 #0: ffff888029337678 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x36/0x340 mm/mmap_lock.c:501
 #1: ffff888033c90998 (rlock-AF_UNIX){+.+.}-{3:3}, at: __skb_try_recv_datagram+0x14e/0x4e0 net/core/datagram.c:264
 #2: ffff888076cd2918 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline]
 #2: ffff888076cd2918 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
 #3: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: page_table_check_set+0x127/0x530 mm/page_table_check.c:112
 #4: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #4: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #4: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: get_non_dying_memcg_start mm/memcontrol.c:862 [inline]
 #4: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: mod_memcg_lruvec_state+0xd5/0x270 mm/memcontrol.c:992
 #5: ffff88801dad3530 (&lruvec->lru_lock){..-.}-{3:3}, at: folio_lruvec_lock_irqsave+0x273/0x550 mm/memcontrol.c:1509
locks held by syz.8.6884/29861: 1, on CPU#0:
 #0: ffffffff902504c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff902504c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7138

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 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:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 29853 Comm: syz.5.6881 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:asm_exc_page_fault+0x0/0x30 arch/x86/include/asm/idtentry.h:595
Code: 74 24 28 ff 74 24 28 ff 74 24 28 ff 74 24 28 ff 74 24 28 e8 82 07 00 00 48 89 c4 48 89 e7 e8 27 1a e3 0a e9 e2 08 00 00 90 90 <f3> 0f 1e fa 0f 01 ca fc e8 63 07 00 00 48 89 c4 48 89 e7 48 8b 74
RSP: 0018:ffffc90005b27a00 EFLAGS: 00040006
RAX: 00007ffffffff001 RBX: 0000000000000038 RCX: 0000000000000038
RDX: 0000000000000001 RSI: 0000200000eb7000 RDI: ffffc90005b27ac0
RBP: ffffc90005b27c50 R08: ffffc90005b27af7 R09: 1ffff92000b64f5e
R10: dffffc0000000000 R11: fffff52000b64f5f R12: ffffc90005b27bc0
R13: ffffc90005b27ac0 R14: ffffc90005b27ac0 R15: 0000200000eb7000
FS:  00007f0abcea76c0(0000) GS:ffff888124dda000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000eb7000 CR3: 0000000031f36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000008e00 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
RIP: 0010:rep_movs_alternative+0x30/0xa0 arch/x86/lib/copy_user_64.S:60
Code: 83 f9 08 73 25 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 e9 3d 6b 04 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08
RSP: 0018:ffffc90005b27a38 EFLAGS: 00050206
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline]
 _inline_copy_from_user include/linux/uaccess.h:185 [inline]
 _copy_from_user+0x7a/0xb0 lib/usercopy.c:18
 copy_from_user include/linux/uaccess.h:222 [inline]
 copy_msghdr_from_user net/socket.c:2643 [inline]
 recvmsg_copy_msghdr net/socket.c:2899 [inline]
 ___sys_recvmsg+0x173/0x5a0 net/socket.c:2971
 do_recvmmsg+0x31a/0x7f0 net/socket.c:3070
 __sys_recvmmsg net/socket.c:3144 [inline]
 __do_sys_recvmmsg net/socket.c:3167 [inline]
 __se_sys_recvmmsg net/socket.c:3160 [inline]
 __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3160
 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: 0033:0x7f0abbf9e0d9
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:00007f0abcea7028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f0abc226090 RCX: 00007f0abbf9e0d9
RDX: 00000000080002c1 RSI: 0000200000000040 RDI: 0000000000000004
RBP: 00007f0abc035024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0abc226128 R14: 00007f0abc226090 R15: 00007ffff38dbde8
 </TASK>