INFO: task syz.9.279:8064 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.279 state:D stack:29024 pid:8064 tgid:8062 ppid:6676 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] vfs_unlink+0xed/0x6d0 fs/namei.c:5462 filename_unlinkat+0x3d3/0x610 fs/namei.c:5546 __do_sys_unlinkat fs/namei.c:5575 [inline] __se_sys_unlinkat+0x83/0x1a0 fs/namei.c:5567 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3f846fc819 RSP: 002b:00007f3f82935028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 00007f3f84976090 RCX: 00007f3f846fc819 RDX: 0000000000000000 RSI: 0000200000000480 RDI: ffffffffffffff9c RBP: 00007f3f84792c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3f84976128 R14: 00007f3f84976090 R15: 00007fffc3b2ac18 INFO: task syz.9.279:8067 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.279 state:D stack:26048 pid:8067 tgid:8062 ppid:6676 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] process_measurement+0x457/0x1c90 security/integrity/ima/ima_main.c:282 ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:667 security_file_post_open+0xb3/0x260 security/security.c:2653 do_open fs/namei.c:4679 [inline] path_openat+0x2e88/0x38a0 fs/namei.c:4836 do_file_open+0x23e/0x4a0 fs/namei.c:4865 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3f846fc819 RSP: 002b:00007f3f82914028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3f84976180 RCX: 00007f3f846fc819 RDX: 0000000000183042 RSI: 0000200000000200 RDI: ffffffffffffff9c RBP: 00007f3f84792c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000015 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3f84976218 R14: 00007f3f84976180 R15: 00007fffc3b2ac18 Showing all locks held in the system: 4 locks held by rcuc/0/20: 1 lock held by khungtaskd/37: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:2/41: 2 locks held by getty/5551: #0: ffff8880379b70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5794: 3 locks held by kworker/1:4/5800: 3 locks held by syz.9.279/8063: 3 locks held by syz.9.279/8064: #0: ffff888053c60480 (sb_writers#27){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805f041ad8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88805f041ad8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2929 [inline] #1: ffff88805f041ad8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2940 [inline] #1: ffff88805f041ad8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: filename_unlinkat+0x2ad/0x610 fs/namei.c:5527 #2: ffff88805f040b68 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #2: ffff88805f040b68 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: vfs_unlink+0xed/0x6d0 fs/namei.c:5462 1 lock held by syz.9.279/8067: #0: ffff88805f040b68 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88805f040b68 (&sb->s_type->i_mutex_key#36){+.+.}-{4:4}, at: process_measurement+0x457/0x1c90 security/integrity/ima/ima_main.c:282 1 lock held by syz-executor/8935: 3 locks held by syz.2.512/10267: 1 lock held by syz.7.515/10316: 2 locks held by udevadm/10310: 7 locks held by udevadm/10318: 2 locks held by cmp/10319: 1 lock held by syz.1.514/10321: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 41 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4313 [inline] RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline] RIP: 0010:lockdep_hardirqs_on_prepare+0xb1/0x260 kernel/locking/lockdep.c:4410 Code: 00 65 48 8b 1d 18 c1 ae 10 48 8b 83 a8 0b 00 00 48 89 83 90 0b 00 00 48 c7 c7 5c e3 57 8d e8 c6 2e 84 09 65 ff 05 9f 07 af 10 <83> bb b0 0b 00 00 00 0f 8e d1 00 00 00 49 89 de 49 81 c6 b8 0b 00 RSP: 0018:ffffc90000b27818 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff88801f69db80 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8d57e35c RDI: ffffffff8ba67a80 RBP: ffffc90000b27958 R08: ffffffff8f6a74b7 R09: 1ffffffff1ed4e96 R10: dffffc0000000000 R11: fffffbfff1ed4e97 R12: dffffc0000000000 R13: 1ffff92000164f14 R14: ffff8880b8938d60 R15: ffff8880b8938d60 FS: 0000000000000000(0000) GS:ffff888126432000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f379f79d000 CR3: 00000000367e0000 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:178 [inline] _raw_spin_unlock_irqrestore+0x30/0x80 kernel/locking/spinlock.c:194 unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline] rt_mutex_slowunlock+0x4a7/0x8b0 kernel/locking/rtmutex.c:1454 spin_unlock include/linux/spinlock_rt.h:109 [inline] napi_skb_cache_get+0x2e4/0x410 net/core/skbuff.c:297 __alloc_skb+0x19a/0x7d0 net/core/skbuff.c:696 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x29f/0xbc0 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245