INFO: task syz.2.23:6455 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.23 state:D stack:27288 pid:6455 tgid:6455 ppid:6258 task_flags:0x40004c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1742/0x4c30 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 rwsem_down_write_slowpath+0x91a/0x10b0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:312 [inline] exit_mmap+0x283/0xb20 mm/mmap.c:1288 __mmput+0x118/0x420 kernel/fork.c:1133 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x22f0 kernel/exit.c:954 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 __do_sys_exit_group kernel/exit.c:1118 [inline] __se_sys_exit_group kernel/exit.c:1116 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116 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+0x8a/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f0f29b8f749 RSP: 002b:00007ffe93470e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0f29b8f749 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffe93470ecc R08: 0000000593470f5f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 000000000001e89a R15: 00007ffe93470f20 INFO: task syz.2.23:6455 is blocked on an rw-semaphore, but the owner is not found. INFO: task syz.3.24:6458 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.24 state:D stack:25928 pid:6458 tgid:6457 ppid:6256 task_flags:0x40054c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1742/0x4c30 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 rwsem_down_write_slowpath+0x91a/0x10b0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:312 [inline] exit_mmap+0x283/0xb20 mm/mmap.c:1288 __mmput+0x118/0x420 kernel/fork.c:1133 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x22f0 kernel/exit.c:954 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1251/0x1300 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [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+0x217/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fe05278f749 RSP: 002b:00007fe0536e20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fe0529e5fa8 RCX: 00007fe05278f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe0529e5fa8 RBP: 00007fe0529e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe0529e6038 R14: 00007ffcb9bebab0 R15: 00007ffcb9bebb98 INFO: task syz.3.24:6458 is blocked on an rw-semaphore, but the owner is not found. Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8db388a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8db388a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8db388a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:4/60: #0: ffff8880b883a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638 #1: ffff8880b8824048 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline] #1: ffff8880b8824048 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2270/0x4c30 kernel/sched/core.c:6923 #2: ffff8880b8825958 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline] #2: ffff8880b8825958 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1085 2 locks held by kworker/u8:9/2940: #0: ffff88813fe29148 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe29148 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x93a/0x16a0 kernel/workqueue.c:3346 #1: ffffc9000b947b80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000b947b80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x16a0 kernel/workqueue.c:3346 2 locks held by getty/5481: #0: ffff88814d2a00a0 (&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+0x5ce/0x1aa0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/6145: #0: ffff8880796ecd20 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #0: ffff8880796ecd20 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:579 1 lock held by syz-executor/6252: #0: ffff888023991760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff888023991760 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x283/0xb20 mm/mmap.c:1288 1 lock held by syz-executor/6255: #0: ffff88807e7657e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff88807e7657e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x283/0xb20 mm/mmap.c:1288 1 lock held by syz-executor/6256: #0: ffff88807e7637a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff88807e7637a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x283/0xb20 mm/mmap.c:1288 1 lock held by syz.2.23/6455: #0: ffff88802e53a220 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff88802e53a220 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x283/0xb20 mm/mmap.c:1288 1 lock held by syz.3.24/6458: #0: ffff88802e53b7a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff88802e53b7a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x283/0xb20 mm/mmap.c:1288 1 lock held by modprobe/6459: #0: ffff88802e53cd20 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #0: ffff88802e53cd20 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:579 2 locks held by dhcpcd-run-hook/6461: #0: ffffffff8dbedf50 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1488 [inline] #0: ffffffff8dbedf50 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x131/0x4b0 kernel/fork.c:1541 #1: ffff888032434d20 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #1: ffff888032434d20 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x125/0x1ca0 mm/mmap.c:1727 1 lock held by udevd/7783: #0: ffff88807b00b7a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #0: ffff88807b00b7a0 (&mm->mmap_lock){++++}-{4:4}, at: __vm_munmap+0x136/0x380 mm/vma.c:3153 1 lock held by udevd/7790: #0: ffff8880278d4d20 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #0: ffff8880278d4d20 (&mm->mmap_lock){++++}-{4:4}, at: __vm_munmap+0x136/0x380 mm/vma.c:3153 1 lock held by syz.0.776/8041: #0: ffff888079a11760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff888079a11760 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x283/0xb20 mm/mmap.c:1288 1 lock held by syz.5.777/8043: #0: ffff88803135c260 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff88803135c260 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x283/0xb20 mm/mmap.c:1288 1 lock held by syz.6.783/8062: #0: ffff88803135cd20 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff88803135cd20 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x283/0xb20 mm/mmap.c:1288 1 lock held by syz.7.784/8060: #0: ffff88803135a220 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:312 [inline] #0: ffff88803135a220 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x283/0xb20 mm/mmap.c:1288 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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/0x2e0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0x16fb/0x1740 kernel/hung_task.c:495 kthread+0x711/0x890 kernel/kthread.c:463 ret_from_fork+0x4b8/0x860 arch/x86/kernel/process.c:158 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x20/0x70 kernel/kcov.c:217 Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 a0 14 92 65 8b 15 f8 8f 57 10 81 e2 00 01 ff 00 74 11 <81> fa 00 01 00 00 75 35 83 b9 84 16 00 00 00 74 2c 8b 91 60 16 00 RSP: 0018:ffffc900001f0ee0 EFLAGS: 00000006 RAX: ffffffff81ab8948 RBX: 003088d57bb50b20 RCX: ffff88801e65bc80 RDX: 0000000000010000 RSI: 0000000000000018 RDI: 0000000000000040 RBP: 000000000000ccf0 R08: ffffffff99242388 R09: ffffffff81ab887e R10: dffffc0000000000 R11: ffffffff816795c0 R12: 00000040627620bb R13: ffffffffffffffff R14: 0000000000000018 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881267d6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005619930b3a38 CR3: 0000000030e74000 CR4: 00000000003526f0 Call Trace: timekeeping_cycles_to_ns kernel/time/timekeeping.c:399 [inline] timekeeping_get_ns kernel/time/timekeeping.c:404 [inline] ktime_get+0x108/0x1f0 kernel/time/timekeeping.c:826 tick_nohz_irq_enter kernel/time/tick-sched.c:1525 [inline] tick_irq_enter+0xfa/0x2c0 kernel/time/tick-sched.c:1553 irq_enter_rcu+0xa0/0xf0 kernel/softirq.c:668 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0x94/0xc0 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:704 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 53 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 93 88 1e 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000187de0 EFLAGS: 000002c2 RAX: c481dca50aaa2100 RBX: ffffffff81941cd7 RCX: c481dca50aaa2100 RDX: 0000000000000001 RSI: ffffffff8d2428ab RDI: ffffffff8b7e98e0 RBP: ffffc90000187f10 R08: ffff8880b8932fdb R09: 1ffff110171265fb R10: dffffc0000000000 R11: ffffed10171265fc R12: ffffffff8f32b170 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003ccb790 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x71/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147