INFO: task syz-executor464:5874 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor464 state:D stack:26920 pid:5874 tgid:5874 ppid:5873 task_flags:0x40004c flags:0x00004002 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_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1088 __down_read_common kernel/locking/rwsem.c:1263 [inline] __down_read kernel/locking/rwsem.c:1276 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1541 mmap_read_lock include/linux/mmap_lock.h:412 [inline] exit_mm+0xcc/0x2c0 kernel/exit.c:557 do_exit+0x648/0x2300 kernel/exit.c:947 do_group_exit+0x21c/0x2d0 kernel/exit.c:1100 __do_sys_exit_group kernel/exit.c:1111 [inline] __se_sys_exit_group kernel/exit.c:1109 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1109 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7fe4bf429349 RSP: 002b:00007ffd82179b48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe4bf429349 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 00007fe4bf4b52b0 R08: ffffffffffffffb0 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe4bf4b52b0 R13: 0000000000000000 R14: 00007fe4bf4b5e40 R15: 00007fe4bf3f7170 Showing all locks held in the system: 1 lock held by ksoftirqd/0/15: 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: ffff88814db7d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor464/5874: #0: ffff88807ab62ce0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff88807ab62ce0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz-executor464/5875: ============================================= 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: 5875 Comm: syz-executor464 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:lockdep_recursion_inc kernel/locking/lockdep.c:468 [inline] RIP: 0010:lockdep_hardirqs_on_prepare+0xb7/0x2a0 kernel/locking/lockdep.c:4412 Code: a5 01 00 00 65 8b 05 a4 f0 49 11 85 c0 0f 85 c8 01 00 00 65 48 8b 1c 25 08 50 e7 92 48 8b 83 e0 0a 00 00 48 89 83 c8 0a 00 00 <48> c7 c7 e5 dd c7 8d e8 3d f3 e1 09 65 ff 05 a6 f3 49 11 83 bb e8 RSP: 0018:ffffc900043d7480 EFLAGS: 00000046 RAX: c8b901b50a67a6df RBX: ffff8880773c3c00 RCX: 8035f2d3d9c32000 RDX: 0000000000000000 RSI: ffffffff8c04d3e0 RDI: ffffffff8c04d3a0 RBP: ffffc900043d7550 R08: ffffffff8fe3cf37 R09: 1ffffffff1fc79e6 R10: dffffc0000000000 R11: fffffbfff1fc79e7 R12: dffffc0000000000 R13: 1ffff9200087aebc R14: ffffffff9a1a9718 R15: 1ffff9200087ae98 FS: 00007fe4bf3e46c0(0000) GS:ffff8881257ab000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b955f55168 CR3: 0000000011c7e000 CR4: 00000000003526f0 Call Trace: trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194 debug_rcu_head_queue kernel/rcu/rcu.h:237 [inline] __call_rcu_common kernel/rcu/tree.c:3108 [inline] call_rcu+0xc3/0x9c0 kernel/rcu/tree.c:3243 slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x309/0x400 mm/slub.c:4782 remove_vma mm/vma.c:468 [inline] vms_complete_munmap_vmas+0x626/0x8a0 mm/vma.c:1293 do_vmi_align_munmap+0x358/0x420 mm/vma.c:1536 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584 do_munmap+0xe1/0x140 mm/mmap.c:1068 mremap_to+0x2df/0x7a0 mm/mremap.c:1368 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: 0033:0x7fe4bf42b2e9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe4bf3e4228 EFLAGS: 00000246 ORIG_RAX: 0000000000000019 RAX: ffffffffffffffda RBX: 00007fe4bf4b5308 RCX: 00007fe4bf42b2e9 RDX: 0000000000600002 RSI: 0000000000600002 RDI: 0000200000000000 RBP: 00007fe4bf4b5300 R08: 0000200000a00000 R09: 00007fe4bf3e46c0 R10: 0000000000000007 R11: 0000000000000246 R12: 00007fe4bf4b530c R13: 0000200000000000 R14: 00002000000000c0 R15: 00007ffd82179ac8 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.094 msecs