INFO: task syz-executor.0:4489 blocked for more than 143 seconds. Not tainted 5.15.182-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:21504 pid: 4489 ppid: 1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x1b3/0x920 fs/fs-writeback.c:2770 sync_filesystem+0x16d/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x300 fs/super.c:448 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1143 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7efef1b9d0d7 RSP: 002b:00007ffc5a60d628 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007efef1be73b9 RCX: 00007efef1b9d0d7 RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007ffc5a60d6e0 RBP: 00007ffc5a60d6e0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc5a60e7a0 R13: 00007efef1be73b9 R14: 00000000000154bb R15: 0000000000000007 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11bea0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:2/154: #0: ffff888018f80938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900010bfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 2 locks held by getty/3937: #0: ffff88802bbd7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026362e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 2 locks held by syz-executor.0/4489: #0: ffff8880763c40e0 (&type->s_umount_key#32){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff8881473767d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8881473767d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2768 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3529 Comm: syslogd Not tainted 5.15.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:__phys_addr+0xb6/0x170 arch/x86/mm/physaddr.c:31 Code: a0 00 00 00 e8 3b 68 42 00 49 89 df 44 89 f1 49 d3 ef 31 ff 4c 89 fe e8 08 6c 42 00 4d 85 ff 0f 85 a2 00 00 00 e8 1a 68 42 00 <48> 89 d8 5b 41 5e 41 5f c3 48 c7 c0 10 70 eb 8b 48 c1 e8 03 48 b9 RSP: 0018:ffffc90002dff8b0 EFLAGS: 00000293 RAX: ffffffff813555f6 RBX: 000000002ad9c800 RCX: ffff88807e191dc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000000004d R08: dffffc0000000000 R09: fffffbfff1ad1576 R10: fffffbfff1ad1576 R11: 1ffffffff1ad1575 R12: dffffc0000000000 R13: 0000000000000001 R14: 000000000000002e R15: 0000000000000000 FS: 00007fcc6f9d1c80(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f5e9f81168 CR3: 0000000017bed000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kmap_to_page include/linux/highmem-internal.h:150 [inline] check_heap_object mm/usercopy.c:236 [inline] __check_object_size+0xc7/0x410 mm/usercopy.c:286 check_object_size include/linux/thread_info.h:199 [inline] check_copy_size include/linux/thread_info.h:232 [inline] copy_to_iter include/linux/uio.h:152 [inline] simple_copy_to_iter+0x3e/0x60 net/core/datagram.c:527 __skb_datagram_iter+0xde/0x740 net/core/datagram.c:425 skb_copy_datagram_iter+0xad/0x1f0 net/core/datagram.c:541 skb_copy_datagram_msg include/linux/skbuff.h:3744 [inline] __unix_dgram_recvmsg+0x671/0xd50 net/unix/af_unix.c:2343 sock_recvmsg_nosec net/socket.c:966 [inline] sock_recvmsg net/socket.c:984 [inline] sock_read_iter+0x2a2/0x340 net/socket.c:1057 call_read_iter include/linux/fs.h:2166 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x725/0xcf0 fs/read_write.c:485 ksys_read+0x14d/0x250 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fcc6fb21407 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:00007ffca7f4d410 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fcc6f9d1c80 RCX: 00007fcc6fb21407 RDX: 00000000000000ff RSI: 000055d9f6904950 RDI: 0000000000000000 RBP: 000055d9f6904910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055d9f6904989 R13: 0000000000000000 R14: 000055d9f6904950 R15: 000055d9ca783d98