INFO: task syz.1.17:6608 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.17 state:D stack:28232 pid:6608 tgid:6607 ppid:6302 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:980 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:911 vfs_fallocate+0x672/0x7f0 fs/open.c:342 ksys_fallocate fs/open.c:366 [inline] __do_sys_fallocate fs/open.c:371 [inline] __se_sys_fallocate fs/open.c:369 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:369 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f03afb35d29 RSP: 002b:00007f03aeda6038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007f03afd25fa0 RCX: 00007f03afb35d29 RDX: 0000000000000000 RSI: 0000000000000011 RDI: 0000000000000004 RBP: 00007f03afbb1b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000001000074000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f03afd25fa0 R15: 00007ffd8a42a038 INFO: task syz.0.16:6621 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.16 state:D stack:28232 pid:6621 tgid:6619 ppid:6298 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:980 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:911 vfs_fallocate+0x672/0x7f0 fs/open.c:342 ksys_fallocate fs/open.c:366 [inline] __do_sys_fallocate fs/open.c:371 [inline] __se_sys_fallocate fs/open.c:369 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:369 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f81bb905d29 RSP: 002b:00007f81bab7e038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007f81bbaf5fa0 RCX: 00007f81bb905d29 RDX: 0000000000000000 RSI: 0000000000000011 RDI: 0000000000000004 RBP: 00007f81bb981b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000001000074000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f81bbaf5fa0 R15: 00007ffc07a960d8 INFO: task syz.4.20:6622 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.20 state:D stack:28232 pid:6622 tgid:6620 ppid:6307 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:980 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:911 vfs_fallocate+0x672/0x7f0 fs/open.c:342 ksys_fallocate fs/open.c:366 [inline] __do_sys_fallocate fs/open.c:371 [inline] __se_sys_fallocate fs/open.c:369 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:369 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0370b85d29 RSP: 002b:00007f036fdf6038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007f0370d75fa0 RCX: 00007f0370b85d29 RDX: 0000000000000000 RSI: 0000000000000011 RDI: 0000000000000004 RBP: 00007f0370c01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000001000074000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0370d75fa0 R15: 00007ffd3f05fcf8 Showing all locks held in the system: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d5aa840 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5aa840 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5aa840 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:9/3747: 5 locks held by kworker/u8:10/3760: 2 locks held by getty/5559: #0: ffff88823bf408a0 (&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+0x444/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz.3.19/6603: 1 lock held by syz.1.17/6608: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.0.16/6621: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.4.20/6622: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.5.21/6899: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.7.23/6901: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.8.24/6905: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.6.22/6907: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.9.25/6909: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.2.26/6988: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.1.27/7003: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.3.28/7029: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.4.30/7033: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.0.29/7032: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.5.31/7104: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.7.32/7172: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.9.35/7174: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.8.33/7176: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 1 lock held by syz.6.34/7178: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 3 locks held by kworker/u8:14/7180: #0: ffff88814d345138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88814d345138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000a3e7ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000a3e7ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 5 locks held by syz-executor/7203: 2 locks held by syz-executor/7213: #0: ffffffff8e8c9ae0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e8c98d8 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff8e8c98d8 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff8e8c98d8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790 net/netlink/genetlink.c:1209 7 locks held by syz-executor/7225: #0: ffff8880334c6480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline] #0: ffff8880334c6480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88802901ac78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8881453ec698 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881453ec698 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e0f4098 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 #4: ffff88805b6980d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff88805b6980d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #5: ffff88805b69d300 (&devlink->lock_key#26){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582 #6: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142 4 locks held by syz-executor/7226: #0: ffff8880334c6480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline] #0: ffff8880334c6480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88803aa6d078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8881453ec698 (kn->active#58){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8881453ec698 (kn->active#58){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e0f4098 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 1 lock held by syz.2.36/7253: #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff888149b29568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:911 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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/0x300 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+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 8e 05 ba fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bf bd 1b fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 5a 77 bf 05 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90000167870 EFLAGS: 00000202 RAX: 1ffffffff31d2100 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff98e910f0 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8504a780 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff98e90e60 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126ef7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff7f8b9230 CR3: 0000000030620000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1961 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3091 [inline] console_flush_all+0x666/0xb40 kernel/printk/printk.c:3199 __console_flush_and_unlock+0x9b/0x160 kernel/printk/printk.c:3258 legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3611 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245