INFO: task syz.1.2004:26477 blocked for more than 143 seconds. Tainted: G W 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2004 state:D stack:21800 pid:26477 tgid:26476 ppid:25799 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1b7/0xa50 fs/fs-writeback.c:2833 __iterate_supers+0x13a/0x290 fs/super.c:924 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3c9165ebe9 RSP: 002b:00007f3c8f8c6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f3c91885fa0 RCX: 00007f3c9165ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f3c91885fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3c91886038 R14: 00007f3c91885fa0 R15: 00007ffd4db9e008 INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Tainted: G W 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 26718 Comm: udevd Tainted: G W 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:-1 [inline] RIP: 0010:unwind_next_frame+0xc3f/0x2390 arch/x86/kernel/unwind_orc.c:585 Code: 85 f9 0c 00 00 48 8d 43 08 4c 39 f8 0f 97 c1 4c 39 e0 0f 96 c0 20 c8 3c 01 0f 85 df 0c 00 00 48 89 df e8 84 23 00 00 48 89 c3 <48> bd 00 00 00 00 00 fc ff df 48 8b 44 24 30 80 3c 28 00 4c 8b 7c RSP: 0018:ffffc90004766b98 EFLAGS: 00000202 RAX: ffffffff81aadf1c RBX: ffffffff81aadf1c RCX: 1ffff920008ecd01 RDX: ffffffff8fa576fe RSI: 0000000000000002 RDI: ffffc90004766d58 RBP: 1ffff920008ecd9a R08: 0000000000000005 R09: 0000000000000000 R10: ffffc90004766d18 R11: fffff520008ecda5 R12: ffffc90004768000 R13: 1ffff920008ecd9b R14: ffffc90004766cc8 R15: ffffc90004760000 FS: 00007fa980e8f880(0000) GS:ffff8881268c5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa9804f0000 CR3: 000000003225c000 CR4: 00000000003526f0 Call Trace: __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 mm/page_owner.c:156 __set_page_owner+0x8d/0x490 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x2119/0x21b0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 folio_alloc_mpol_noprof mm/mempolicy.c:2435 [inline] vma_alloc_folio_noprof+0xe4/0x280 mm/mempolicy.c:2470 folio_prealloc+0x30/0x180 mm/memory.c:-1 alloc_anon_folio mm/memory.c:4997 [inline] do_anonymous_page mm/memory.c:5054 [inline] do_pte_missing mm/memory.c:4232 [inline] handle_pte_fault mm/memory.c:6052 [inline] __handle_mm_fault mm/memory.c:6195 [inline] handle_mm_fault+0x12ee/0x3400 mm/memory.c:6364 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74 Code: d4 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 73 e8 eb c5 a4 e9 8f d4 04 00 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48 RSP: 0018:ffffc900047677f8 EFLAGS: 00050206 RAX: ffffffff84b4eb01 RBX: ffff88803f31a000 RCX: 0000000000001000 RDX: 0000000000000000 RSI: ffff88803f31a000 RDI: 00007fa9804f0000 RBP: ffffc90004767948 R08: ffff88803f31afff R09: 1ffff11007e635ff R10: dffffc0000000000 R11: ffffed1007e63600 R12: 1ffff920008ecfaf R13: 00007fa9804f0000 R14: ffffc90004767d88 R15: 0000000000001000 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:300 [inline] iterate_and_advance include/linux/iov_iter.h:328 [inline] _copy_to_iter+0x24c/0x16f0 lib/iov_iter.c:185 copy_page_to_iter+0x10c/0x1c0 lib/iov_iter.c:362 copy_folio_to_iter include/linux/uio.h:204 [inline] filemap_read+0xa1b/0x11a0 mm/filemap.c:2763 blkdev_read_iter+0x311/0x440 block/fops.c:849 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x560/0xa30 fs/read_write.c:572 ksys_read+0x14b/0x260 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa980f7d407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffc74fc5580 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fa980e8f880 RCX: 00007fa980f7d407 RDX: 0000000000040000 RSI: 00007fa9804e0000 RDI: 0000000000000009 RBP: 0000564f85cbb070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 0000564f85cbd6f8 R15: 00007fa9816d339c