INFO: task udevd:14409 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25752 pid:14409 ppid:5143 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 io_schedule+0x80/0xd0 kernel/sched/core.c:9023 folio_wait_bit_common+0x881/0xfa0 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7f0 mm/filemap.c:3791 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x350 block/partitions/core.c:718 adfspart_check_POWERTEC+0x93/0xed0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:600 [inline] bdev_disk_changed+0x755/0x1450 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:672 blkdev_get_by_dev+0x3a9/0x610 block/bdev.c:814 blkdev_open+0x14e/0x360 block/fops.c:589 do_dentry_open+0x880/0x14b0 fs/open.c:929 do_open fs/namei.c:3640 [inline] path_openat+0x284f/0x3270 fs/namei.c:3797 do_filp_open+0x1f2/0x430 fs/namei.c:3824 do_sys_openat2+0x134/0x1d0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1556ca7407 RSP: 002b:00007fff4d1e7a90 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f155745c880 RCX: 00007f1556ca7407 RDX: 00000000000a0800 RSI: 0000562a186cb980 RDI: ffffffffffffff9c RBP: 0000562a186c0910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000562a186d8e00 R13: 0000562a186d8410 R14: 0000000000000000 R15: 0000562a186d8e00 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5532: #0: ffff8880211700a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217 1 lock held by udevd/14409: #0: ffff888021c354c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:805 1 lock held by syz.3.3668/18855: #0: ffff888079f7c420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #0: ffff888079f7c420 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x166/0x3f0 mm/util.c:554 1 lock held by syz.3.3668/18856: 1 lock held by syz.1.3673/18865: #0: ffff8880212b9e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #0: ffff8880212b9e20 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x166/0x3f0 mm/util.c:554 4 locks held by syz.1.3673/18866: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf59/0xfa0 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 18866 Comm: syz.1.3673 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:preempt_count_add+0x6/0x1a0 kernel/sched/core.c:5836 Code: 58 0d 00 00 80 e1 07 80 c1 03 38 c1 7c 8b 49 8d be 58 0d 00 00 e8 da f1 82 00 e9 7a ff ff ff e9 f9 fe ff ff f3 0f 1e fa 41 57 <41> 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 80 34 2c 97 48 c1 RSP: 0018:ffffc90003666c28 EFLAGS: 00000202 RAX: ffffffff813b2468 RBX: 1ffff920006ccda1 RCX: 0000000000000002 RDX: ffff888023d0da00 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffc90003666dd0 R09: 000000000000000a R10: 0000000000000004 R11: 0000000000000002 R12: ffffc90003667940 R13: ffffc90003666d08 R14: ffffc90003666d40 R15: dffffc0000000000 FS: 00007f61e9bff6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c369a1f CR3: 000000007d2b9000 CR4: 00000000003506f0 Call Trace: unwind_next_frame+0xb7/0x2990 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x230 mm/page_owner.c:128 __set_page_owner+0x1d/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582 prep_new_page mm/page_alloc.c:1589 [inline] get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501 __folio_alloc+0x10/0x20 mm/page_alloc.c:4533 vma_alloc_folio+0x474/0x8f0 mm/mempolicy.c:2240 shmem_alloc_folio+0x1a9/0x2a0 mm/shmem.c:1679 shmem_alloc_and_acct_folio+0x1cb/0x6c0 mm/shmem.c:1704 shmem_get_folio_gfp+0xe1d/0x2b40 mm/shmem.c:2041 shmem_fault+0x1b8/0x820 mm/shmem.c:2248 __do_fault+0x13b/0x4d0 mm/memory.c:4244 do_read_fault mm/memory.c:4638 [inline] do_fault mm/memory.c:4775 [inline] do_pte_missing mm/memory.c:3689 [inline] handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5188 [inline] handle_mm_fault+0x3945/0x4a50 mm/memory.c:5353 faultin_page mm/gup.c:868 [inline] __get_user_pages+0x604/0x1580 mm/gup.c:1167 populate_vma_page_range+0x2c1/0x380 mm/gup.c:1593 __mm_populate+0x260/0x390 mm/gup.c:1696 mm_populate include/linux/mm.h:3383 [inline] vm_mmap_pgoff+0x2da/0x3f0 mm/util.c:561 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f61e8d9ce59 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:00007f61e9bff028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f61e9015fa0 RCX: 00007f61e8d9ce59 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f61e8e32e6f R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f61e9016038 R14: 00007f61e9015fa0 R15: 00007ffe4afbaf48