INFO: task syz.4.1527:12689 blocked for more than 143 seconds. Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1527 state:D stack:23816 pid:12689 tgid:12688 ppid:5826 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 netfs_wait_for_request+0x161/0x5a0 fs/netfs/misc.c:450 netfs_unbuffered_write_iter_locked+0x8c3/0xc80 fs/netfs/direct_write.c:110 netfs_unbuffered_write_iter+0x414/0x6d0 fs/netfs/direct_write.c:193 v9fs_file_write_iter+0xbf/0x100 fs/9p/vfs_file.c:404 do_iter_readv_writev+0x657/0x950 fs/read_write.c:827 vfs_writev+0x35f/0xde0 fs/read_write.c:1057 do_writev+0x132/0x340 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f46f538e969 RSP: 002b:00007f46f610e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f46f55b5fa0 RCX: 00007f46f538e969 RDX: 0000000000000002 RSI: 0000200000000000 RDI: 0000000000000006 RBP: 00007f46f5410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f46f55b5fa0 R15: 00007ffdce9c1e28 Showing all locks held in the system: 2 locks held by rcu_tasks_trace/29: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4e40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4e40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4e40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:5/193: 2 locks held by getty/5580: #0: ffff8880366da0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 7 locks held by syz-executor/7319: 2 locks held by kworker/u8:17/9631: #0: ffff888146288148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9001b987d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 3 locks held by syz.4.1527/12689: #0: ffff888068ee1cf8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1213 #1: ffff8880345be428 (sb_writers#25){.+.+}-{0:0}, at: do_writev+0x132/0x340 fs/read_write.c:1103 #2: ffff88805b8f87b8 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188 2 locks held by syz.7.1953/14520: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7319 Comm: syz-executor Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__nr_to_section include/linux/mmzone.h:1940 [inline] RIP: 0010:__pfn_to_section include/linux/mmzone.h:2075 [inline] RIP: 0010:lookup_page_ext+0xd5/0x1d0 mm/page_ext.c:251 Code: 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 ee 00 00 00 48 8b 6d 00 48 85 ed 0f 84 bf 00 00 00 e8 4b a5 8d ff <41> 83 e4 7f 49 c1 e4 05 4c 01 e5 e8 3b a5 8d ff 48 8d 7d 10 48 b8 RSP: 0018:ffffc90003dd7588 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000027f05 RCX: ffffffff822e71a1 RDX: ffff888031924880 RSI: ffffffff822e7215 RDI: 0000000000000006 RBP: ffff88813fffa400 R08: 0000000000000006 R09: 0000000000001000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000004 R13: ffff88823ffef400 R14: 0000000000000000 R15: 0000000000000000 FS: 000055558ecee500(0000) GS:ffff888124865000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f20156e56c0 CR3: 0000000049b62000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: page_ext_iter_begin include/linux/page_ext.h:132 [inline] page_table_check_set+0x1e6/0x750 mm/page_table_check.c:113 __page_table_check_ptes_set+0x318/0x420 mm/page_table_check.c:209 page_table_check_ptes_set include/linux/page_table_check.h:76 [inline] set_ptes include/linux/pgtable.h:292 [inline] __copy_present_ptes mm/memory.c:973 [inline] copy_present_ptes mm/memory.c:1056 [inline] copy_pte_range mm/memory.c:1179 [inline] copy_pmd_range mm/memory.c:1267 [inline] copy_pud_range mm/memory.c:1304 [inline] copy_p4d_range mm/memory.c:1328 [inline] copy_page_range+0x234d/0x5d90 mm/memory.c:1416 dup_mmap+0xe88/0x21d0 mm/mmap.c:1838 dup_mm kernel/fork.c:1477 [inline] copy_mm kernel/fork.c:1529 [inline] copy_process+0x4081/0x76a0 kernel/fork.c:2169 kernel_clone+0xfc/0x960 kernel/fork.c:2599 __do_sys_clone+0xce/0x120 kernel/fork.c:2742 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f20149851d3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd9fef7528 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f20149851d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055558ecee7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000cb147 R15: 00007ffd9fef76c0