INFO: task syz.0.15:6617 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.15 state:D stack:28040 pid:6617 tgid:6616 ppid:6351 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 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:870 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:904 vfs_fallocate+0x66f/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/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd5decbdff9 RSP: 002b:00007fd5ddf3e038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007fd5dee75f80 RCX: 00007fd5decbdff9 RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004 RBP: 00007fd5ded30296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd5dee75f80 R15: 00007ffc4b04db08 INFO: task syz.3.18:6631 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.18 state:D stack:27400 pid:6631 tgid:6630 ppid:6353 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 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:870 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:904 vfs_fallocate+0x66f/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/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0c7606dff9 RSP: 002b:00007f0c752e6038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007f0c76225f80 RCX: 00007f0c7606dff9 RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004 RBP: 00007f0c760e0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0c76225f80 R15: 00007fffb4b347d8 INFO: task syz.2.17:6638 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.17 state:D stack:28264 pid:6638 tgid:6637 ppid:6354 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 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:870 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:904 vfs_fallocate+0x66f/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/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faa14eedff9 RSP: 002b:00007faa14166038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007faa150a5f80 RCX: 00007faa14eedff9 RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004 RBP: 00007faa14f60296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007faa150a5f80 R15: 00007fff6a28cfd8 INFO: task syz.4.19:6643 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.19 state:D stack:28264 pid:6643 tgid:6642 ppid:6362 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 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:870 [inline] blkdev_fallocate+0x263/0x550 block/fops.c:904 vfs_fallocate+0x66f/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/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa83900dff9 RSP: 002b:00007fa838286038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007fa8391c5f80 RCX: 00007fa83900dff9 RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004 RBP: 00007fa839080296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa8391c5f80 R15: 00007ffd16b90a18 Showing all locks held in the system: 3 locks held by kworker/0:1/10: 3 locks held by kworker/u8:0/12: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/0:1H/132: 2 locks held by getty/5598: #0: ffff88823bf2e8a0 (&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+0x444/0x1410 drivers/tty/n_tty.c:2222 2 locks held by kworker/1:3/5903: 2 locks held by syz.1.16/6510: 1 lock held by syz.0.15/6617: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.3.18/6631: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.2.17/6638: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.4.19/6643: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.1.20/6941: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 5 locks held by kworker/u8:14/6963: 1 lock held by syz.0.21/6967: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.3.22/6974: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.2.23/6983: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.4.24/6985: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.1.25/7058: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.0.26/7089: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.3.27/7098: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.2.28/7100: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.4.29/7102: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.1.30/7179: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.0.31/7205: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.3.32/7221: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.2.33/7223: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 2 locks held by kworker/u8:16/7230: 2 locks held by kworker/u8:17/7231: 8 locks held by syz-executor/7247: 2 locks held by syz-executor/7252: 1 lock held by udevd/7303: 1 lock held by syz.1.35/7382: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.4.34/7388: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 1 lock held by syz.0.36/7398: #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline] #0: ffff888024cdc868 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:904 ============================================= 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 08/18/2025 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:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 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 08/18/2025 RIP: 0010:delay_tsc+0x5b/0xc0 arch/x86/lib/delay.c:79 Code: 90 49 89 d7 49 c1 e7 20 49 09 c7 4d 29 f7 49 39 df 73 53 bf 01 00 00 00 e8 82 e0 99 f6 65 8b 05 ab 51 00 07 85 c0 74 1c f3 90 01 00 00 00 e8 bb de 99 f6 e8 46 3c 01 00 39 c5 75 0e 0f 01 f9 RSP: 0018:ffffc90000167890 EFLAGS: 00000286 RAX: 0000000080000000 RBX: 0000000000000899 RCX: 0000000000000000 RDX: 00000000000000a9 RSI: ffffffff8b621660 RDI: 00000000ffffffff RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8af5ee30 R12: 1ffffffff3275d12 R13: 00000000ffffffff R14: 000000a9e3723686 R15: 0000000000000124 FS: 0000000000000000(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558c06b5c8 CR3: 000000003b0e2000 CR4: 00000000003526f0 Call Trace: udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x166/0x2f0 drivers/tty/serial/8250/8250_port.c:1990 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3288 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3311 [inline] serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3396 console_emit_next_record kernel/printk/printk.c:3118 [inline] console_flush_all+0x695/0xcd0 kernel/printk/printk.c:3226 __console_flush_and_unlock+0xa4/0x240 kernel/printk/printk.c:3285 legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3638 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245