INFO: task syz.7.3000:16102 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.3000 state:D stack:25096 pid:16102 tgid:16102 ppid:12306 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x1737/0x4d30 kernel/sched/core.c:6954 __schedule_loop kernel/sched/core.c:7036 [inline] schedule+0x165/0x360 kernel/sched/core.c:7051 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1187 __down_write_common kernel/locking/rwsem.c:1319 [inline] __down_write kernel/locking/rwsem.c:1328 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1593 mmap_write_lock include/linux/mmap_lock.h:356 [inline] userfaultfd_release_all+0x15a/0x5e0 mm/userfaultfd.c:2055 userfaultfd_release+0xe7/0x1b0 fs/userfaultfd.c:868 __fput+0x449/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f239438e9a9 RSP: 002b:00007fff27c47a08 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f23945b7ba0 RCX: 00007f239438e9a9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f23945b7ba0 R08: 000000000000008c R09: 0000000827c47cff R10: 00007f23945b7ac0 R11: 0000000000000246 R12: 00000000000a994d R13: 00007fff27c47b00 R14: ffffffffffffffff R15: 00007fff27c47b20 Showing all locks held in the system: 2 locks held by ksoftirqd/0/15: #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:644 #1: ffff8880b8624008 (per_cpu_ptr(&psi_seq, cpu)){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:937 1 lock held by khungtaskd/31: #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5609: #0: ffff88814dd560a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz.7.3000/16102: #0: ffff8880336737a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:356 [inline] #0: ffff8880336737a0 (&mm->mmap_lock){++++}-{4:4}, at: userfaultfd_release_all+0x15a/0x5e0 mm/userfaultfd.c:2055 1 lock held by syz.7.3000/16103: 1 lock held by syz.7.3000/16108: #0: ffff8880336737a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff8880336737a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 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: 16103 Comm: syz.7.3000 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_cmp1+0x8/0x90 kernel/kcov.c:276 Code: cc cc cc cc cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 14 25 08 50 e7 92 65 8b 0d 88 4e 27 11 81 e1 00 01 ff 00 RSP: 0018:ffffc90018dbf278 EFLAGS: 00000293 RAX: ffffffff8b7829a0 RBX: 0000000000000001 RCX: 000000008cdac601 RDX: ffffffff8cdac6a1 RSI: 0000000000000001 RDI: 000000000000000f RBP: ffffc90018dbf450 R08: ffff888047c91e00 R09: 0000000000000004 R10: 0000000000000003 R11: 0000000000000002 R12: ffff88803198ae10 R13: dffffc0000000000 R14: 00001ffed38ecfff R15: 000000000000000f FS: 00007f23952366c0(0000) GS:ffff8881257ab000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f486a183178 CR3: 0000000026026000 CR4: 00000000003526f0 Call Trace: mas_safe_pivot lib/maple_tree.c:713 [inline] mas_validate_limits lib/maple_tree.c:7487 [inline] mt_validate+0xbb0/0x4380 lib/maple_tree.c:7609 validate_mm+0xb6/0x4b0 mm/vma.c:651 vma_link+0x366/0x450 mm/vma.c:1799 copy_vma+0x70c/0x940 mm/vma.c:1880 copy_vma_and_data mm/mremap.c:1184 [inline] move_vma+0x81f/0x1840 mm/mremap.c:1282 mremap_to+0x6d6/0x7a0 mm/mremap.c:1406 remap_move mm/mremap.c:1863 [inline] do_mremap mm/mremap.c:1906 [inline] __do_sys_mremap mm/mremap.c:1970 [inline] __se_sys_mremap+0xa0b/0xef0 mm/mremap.c:1938 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: 0033:0x7f239438e9a9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2395236038 EFLAGS: 00000246 ORIG_RAX: 0000000000000019 RAX: ffffffffffffffda RBX: 00007f23945b5fa0 RCX: 00007f239438e9a9 RDX: 0000000000001000 RSI: 0000000000001000 RDI: 0000200000000000 RBP: 00007f2394410d69 R08: 0000200000481000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f23945b5fa0 R15: 00007fff27c478a8