INFO: task syz.7.888:15079 blocked for more than 143 seconds. Not tainted 6.14.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.888 state:D stack:23872 pid:15079 tgid:15078 ppid:14416 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 request_wait_answer fs/fuse/dev.c:453 [inline] __fuse_request_send fs/fuse/dev.c:467 [inline] __fuse_simple_request+0xe2a/0x1850 fs/fuse/dev.c:561 fuse_simple_request fs/fuse/fuse_i.h:1197 [inline] fuse_send_open fs/fuse/file.c:51 [inline] fuse_file_open+0x626/0xb20 fs/fuse/file.c:146 fuse_do_open+0x4f/0xc0 fs/fuse/file.c:175 fuse_dir_open+0x110/0x220 fs/fuse/dir.c:1676 do_dentry_open+0xdec/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f58eb78bad0 RSP: 002b:00007f58ec569df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000010000 RCX: 00007f58eb78bad0 RDX: 0000000000010000 RSI: 0000400000000000 RDI: 00000000ffffff9c RBP: 0000400000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000400000000000 R13: 00007f58ec569eb0 R14: 0000000000000000 R15: 0000400000002280 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by getty/5584: #0: ffff88814d1a40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/16154: 1 lock held by syz-executor/17590: #0: ffffffff8eb3e438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline] #0: ffffffff8eb3e438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x820 kernel/rcu/tree_exp.h:996 3 locks held by syz.8.1196/18026: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 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: 18026 Comm: syz.8.1196 Not tainted 6.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:save_stack+0xa6/0x1f0 mm/page_owner.c:152 Code: 80 00 00 00 48 89 df 31 f6 e8 b6 63 f6 ff 65 48 8b 1c 25 00 d5 03 00 48 81 c3 90 05 00 00 49 89 df 49 c1 ef 03 43 0f b6 04 27 <84> c0 0f 85 dd 00 00 00 44 0f b7 33 44 89 f6 81 e6 00 04 00 00 31 RSP: 0018:ffffc900040ef120 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff888026352390 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900040ef1e0 RBP: ffffc900040ef250 R08: ffffc900040ef1df R09: 0000000000000000 R10: ffffc900040ef160 R11: fffff5200081de3c R12: dffffc0000000000 R13: 1ffff9200081de28 R14: 0000000000000001 R15: 1ffff11004c6a472 FS: 00007f56257c46c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055664e2a9680 CR3: 0000000080b70000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __set_page_owner+0x89/0x530 mm/page_owner.c:320 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270 folio_alloc_mpol_noprof+0x36/0x70 mm/mempolicy.c:2289 shmem_alloc_folio mm/shmem.c:1863 [inline] shmem_alloc_and_add_folio+0x4a0/0x1090 mm/shmem.c:1902 shmem_get_folio_gfp+0x621/0x1840 mm/shmem.c:2522 shmem_get_folio mm/shmem.c:2628 [inline] shmem_write_begin+0x165/0x350 mm/shmem.c:3278 generic_perform_write+0x346/0x990 mm/filemap.c:4189 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3454 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xacf/0xd10 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f562498bc1f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007f56257c3df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f562498bc1f RDX: 0000000001000000 RSI: 00007f561a200000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005fb6 R10: 0000000000000778 R11: 0000000000000293 R12: 0000000000000004 R13: 00007f56257c3ef0 R14: 00007f56257c3eb0 R15: 00007f561a200000