INFO: task syz.0.17:5969 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:27120 pid:5969 ppid:5917 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 rwsem_down_read_slowpath+0x4f8/0x840 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1250 [inline] __down_read kernel/locking/rwsem.c:1263 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1522 __super_lock fs/super.c:58 [inline] super_lock+0x167/0x360 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] iterate_supers+0x80/0x170 fs/super.c:977 ksys_sync+0x95/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff03f78eec9 RSP: 002b:00007ff03edfe038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007ff03f9e6090 RCX: 00007ff03f78eec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ff03f9e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff03f9e6128 R14: 00007ff03f9e6090 R15: 00007ffe6f870958 INFO: task syz.1.18:5996 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.18 state:D stack:28936 pid:5996 ppid:5972 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 rwsem_down_read_slowpath+0x4f8/0x840 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1250 [inline] __down_read kernel/locking/rwsem.c:1263 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1522 __super_lock fs/super.c:58 [inline] super_lock+0x167/0x360 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] iterate_supers+0x80/0x170 fs/super.c:977 ksys_sync+0x95/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8a1c58eec9 RSP: 002b:00007f8a1d441038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f8a1c7e6090 RCX: 00007f8a1c58eec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f8a1c7e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8a1c7e6128 R14: 00007f8a1c7e6090 R15: 00007ffd067c61b8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:8/3457: 2 locks held by getty/5554: #0: ffff88814cb190a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by syz.0.17/5968: #0: ffff88807e41a0e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.0.17/5969: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.1.18/5995: #0: ffff8880304a80e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.1.18/5996: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.2.19/6021: #0: ffff88807b5620e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.2.19/6023: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.3.20/6045: #0: ffff88807a4ac0e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.3.20/6047: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.4.21/6075: #0: ffff88807e7b20e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.4.21/6076: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.5.22/6110: #0: ffff888023a220e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.5.22/6111: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.6.23/6140: #0: ffff88805ed460e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.6.23/6141: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.7.24/6170: #0: ffff888078c180e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.7.24/6172: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.8.25/6201: #0: ffff88802dc5e0e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.8.25/6202: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.9.26/6236: #0: ffff888057cc00e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.9.26/6237: #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e41a0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 39 Comm: kworker/u4:2 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x10/0x80 kernel/kcov.c:293 Code: 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d d0 2a 7e 7e <65> 8b 15 d1 2a 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc90000aff590 EFLAGS: 00000287 RAX: ffffffff813aa778 RBX: ffffffff8e625968 RCX: ffff88801ee6bc00 RDX: dffffc0000000000 RSI: ffffffff81dcb9d5 RDI: ffffffff81dcb9dd RBP: ffffffff8e62595c R08: ffffc90000aff730 R09: 0000000000000002 R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff8e62595c R13: ffffffff81dcb9dd R14: ffffffff81dcb9d5 R15: ffffffff8e625960 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f6238f1608 CR3: 000000000cb30000 CR4: 00000000003506f0 Call Trace: __orc_find arch/x86/kernel/unwind_orc.c:102 [inline] orc_find arch/x86/kernel/unwind_orc.c:227 [inline] unwind_next_frame+0x4b8/0x2970 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x280 mm/slub.c:3852 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x76f/0xb00 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293