INFO: task syz.3.20:6711 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.20 state:D stack:27632 pid:6711 tgid:6710 ppid:6382 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539 filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 do_sync_mmap_readahead+0x554/0x670 mm/filemap.c:3400 filemap_fault+0x6b5/0x12b0 mm/filemap.c:3549 __do_fault+0x138/0x390 mm/memory.c:5320 do_read_fault mm/memory.c:5755 [inline] do_fault mm/memory.c:5889 [inline] do_pte_missing+0x18ca/0x27a0 mm/memory.c:4401 handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0xcc1/0x1330 mm/memory.c:6580 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0xb7/0x2c0 lib/strncpy_from_user.c:130 Code: 00 00 4c 89 f6 e8 89 74 09 fd 49 83 fe 07 0f 86 9d 00 00 00 48 89 1c 24 4c 89 74 24 08 48 c7 c5 f8 ff ff ff 45 31 ff 4c 89 e3 <4f> 8b 34 3c 48 b8 ff fe fe fe fe fe fe fe 4d 8d 24 06 4d 89 f5 49 RSP: 0018:ffffc90004cdfd10 EFLAGS: 00050246 RAX: ffffffff84b6f367 RBX: 0000000020001000 RCX: ffff888023cd0000 RDX: 0000000000000000 RSI: 0000000000000fe0 RDI: 0000000000000007 RBP: fffffffffffffff8 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed100715ca80 R12: 0000000020001000 R13: dffffc0000000000 R14: 0000000000000fe0 R15: 0000000000000000 getname_flags+0xf3/0x540 fs/namei.c:157 getname include/linux/fs.h:2498 [inline] do_sys_openat2+0xbc/0x200 fs/open.c:1426 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc57c1c9eb9 RSP: 002b:00007fc57b44e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc57c365f80 RCX: 00007fc57c1c9eb9 RDX: 0000000000048882 RSI: 0000000020001000 RDI: ffffffffffffff9c RBP: 00007fc57c23793e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fc57c365f80 R15: 00007ffc082dc168 INFO: task syz.4.332:7459 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.332 state:D stack:27720 pid:7459 tgid:7458 ppid:6385 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539 filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 do_sync_mmap_readahead+0x554/0x670 mm/filemap.c:3400 filemap_fault+0x6b5/0x12b0 mm/filemap.c:3549 __do_fault+0x138/0x390 mm/memory.c:5320 do_read_fault mm/memory.c:5755 [inline] do_fault mm/memory.c:5889 [inline] do_pte_missing+0x18ca/0x27a0 mm/memory.c:4401 handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0xcc1/0x1330 mm/memory.c:6580 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0xb7/0x2c0 lib/strncpy_from_user.c:130 Code: 00 00 4c 89 f6 e8 89 74 09 fd 49 83 fe 07 0f 86 9d 00 00 00 48 89 1c 24 4c 89 74 24 08 48 c7 c5 f8 ff ff ff 45 31 ff 4c 89 e3 <4f> 8b 34 3c 48 b8 ff fe fe fe fe fe fe fe 4d 8d 24 06 4d 89 f5 49 RSP: 0018:ffffc90005e87d10 EFLAGS: 00050246 RAX: ffffffff84b6f367 RBX: 0000000020001000 RCX: ffff88802b4c0000 RDX: 0000000000000000 RSI: 0000000000000fe0 RDI: 0000000000000007 RBP: fffffffffffffff8 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed100889d860 R12: 0000000020001000 R13: dffffc0000000000 R14: 0000000000000fe0 R15: 0000000000000000 getname_flags+0xf3/0x540 fs/namei.c:157 getname include/linux/fs.h:2498 [inline] do_sys_openat2+0xbc/0x200 fs/open.c:1426 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb1c5119eb9 RSP: 002b:00007fb1c439e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb1c52b5f80 RCX: 00007fb1c5119eb9 RDX: 0000000000048882 RSI: 0000000020001000 RDI: ffffffffffffff9c RBP: 00007fb1c518793e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fb1c52b5f80 R15: 00007ffcb15c42f8 Showing all locks held in the system: 3 locks held by kworker/0:1/10: #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc900000f7b80 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900000f7b80 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff888027c07260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x224/0x3e0 drivers/net/netdevsim/fib.c:1490 6 locks held by kworker/u8:0/12: 2 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/38: #0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/0:2/886: #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90004307b80 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90004307b80 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff888025def260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x224/0x3e0 drivers/net/netdevsim/fib.c:1490 2 locks held by getty/5558: #0: ffff88814ea170a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211 2 locks held by syz.2.17/6616: 1 lock held by syz.3.20/6711: #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 1 lock held by syz.4.332/7459: #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 1 lock held by syz.0.514/7849: #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 1 lock held by syz.1.607/8048: #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 1 lock held by syz.2.1142/9159: #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 1 lock held by syz.4.1210/9309: #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 1 lock held by syz-executor/11411: 1 lock held by syz.2.2242/11442: #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 1 lock held by syz.0.3218/13500: #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 1 lock held by syz-executor/14046: #0: ffffffff8e8a5678 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8e8a5678 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027 1 lock held by syz.2.4313/15800: #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #0: ffff888021fefd38 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_unbounded+0x193/0x8c0 mm/readahead.c:233 5 locks held by syz.4.4338/15858: 3 locks held by syz.1.4339/15859: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 15858 Comm: syz.4.4338 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__lock_acquire+0x342/0x2cf0 kernel/locking/lockdep.c:5185 Code: 8b 54 24 10 83 e2 01 c1 e2 12 44 09 ea c1 e3 14 09 d3 8b 14 24 c1 e2 13 41 c1 e4 15 41 09 d4 41 09 cc 41 09 dc 45 89 64 c7 20 <41> 89 7c c7 24 4c 89 7c 24 20 4d 8d 2c c7 41 81 e4 ff 1f 00 00 4c RSP: 0018:ffffc9000fd9ef50 EFLAGS: 00000002 RAX: 000000000000000a RBX: 0000000000020000 RCX: 000000000000000b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000002 R08: ffffffff81741f55 R09: ffffffff8d5ae880 R10: ffffc9000fd9f258 R11: ffffffff81ac41f0 R12: 000000000002000b R13: 0000000000020000 R14: ffff88804456bc80 R15: ffff88804456c810 FS: 0000000000000000(0000) GS:ffff888126d03000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000240 CR3: 0000000032540000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kmem_cache_free+0x18f/0x8d0 mm/slub.c:6779 anon_vma_chain_free mm/rmap.c:146 [inline] unlink_anon_vmas+0x2cc/0x670 mm/rmap.c:420 free_pgtables+0x735/0x9d0 mm/memory.c:414 exit_mmap+0x431/0xb10 mm/mmap.c:1288 __mmput+0xcb/0x3d0 kernel/fork.c:1173 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x658/0x2310 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x125d/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9a12689eb9 Code: Unable to access opcode bytes at 0x7f9a12689e8f. RSP: 002b:00007f9a119060e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f9a12825f88 RCX: 00007f9a12689eb9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f9a12825f8c RBP: 00007f9a12825f80 R08: 3fffffffffffffff R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00007f9a12825f8c R13: 0000000000000000 R14: 00007ffef8a1a0b0 R15: 00007ffef8a1a198