INFO: task syz.4.4862:23010 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.4862 state:D stack:28760 pid:23010 tgid:23003 ppid:15933 task_flags:0x400040 flags:0x08080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 blk_debugfs_lock_nomemsave block/blk.h:758 [inline] blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561 sg_ioctl_common drivers/scsi/sg.c:1124 [inline] sg_ioctl+0x45b/0x2220 drivers/scsi/sg.c:1158 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x5ea/0x950 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x23e/0x6f0 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf6fdf01c RSP: 002b:00000000f53ac50c EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000000001276 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by init/1: 1 lock held by khungtaskd/31: #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/36: 2 locks held by syslogd/4981: 1 lock held by udevd/5000: 3 locks held by dhcpcd/5295: 3 locks held by dhcpcd/5296: #0: ffff888022af7178 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:611 [inline] #0: ffff888022af7178 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:441 [inline] #0: ffff888022af7178 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x36/0x340 mm/mmap_lock.c:501 #1: ffffffff8ea85600 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4393 [inline] #1: ffffffff8ea85600 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xbd/0x310 mm/page_alloc.c:4418 #2: ffff8880b863aee0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:660 3 locks held by dhcpcd/5297: 2 locks held by getty/5386: #0: ffff8880328560a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000323b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 1 lock held by sshd-session/5616: 2 locks held by syz-executor/5617: 2 locks held by udevd/5632: #0: ffff888034d66280 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #0: ffff888034d66280 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_fault+0x95e/0x1300 mm/filemap.c:3562 #1: ffffffff8ea85600 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4393 [inline] #1: ffffffff8ea85600 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xbd/0x310 mm/page_alloc.c:4418 4 locks held by udevd/10146: #0: ffff888022ec7878 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183 #1: ffff888229a97880 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff888021e88698 (kn->active#31){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888021e88698 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff8880788fa1d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] #3: ffff8880788fa1d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 2 locks held by udevd/16443: 3 locks held by udevd/16445: 3 locks held by syz-executor/16755: 6 locks held by kworker/1:5/16854: 2 locks held by syz-executor/21324: 2 locks held by syz.4.4862/23004: 1 lock held by syz.4.4862/23010: #0: ffff88802763f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff88802763f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561 3 locks held by syz-executor/23279: 1 lock held by syz.3.4994/23504: #0: ffff88802763f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff88802763f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:770 [inline] #0: ffff88802763f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:788 1 lock held by syz.3.4994/23507: #0: ffff88802763f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:758 [inline] #0: ffff88802763f868 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove+0x20/0x40 kernel/trace/blktrace.c:561 2 locks held by syz.7.5088/23832: 8 locks held by syz.0.5089/23833: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 23833 Comm: syz.0.5089 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401 Code: e8 8e f3 80 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 6f 49 ec fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0000:ffffc90003756d98 EFLAGS: 00000006 RAX: 1ffffffff34f1b05 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc90003756f30 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff8544c3f0 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff9a78dac0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812529f000(0063) knlGS:0000000056dbb480 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f70ee10e CR3: 0000000156cd6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:806 [inline] serial8250_console_write+0x540/0x1ba0 drivers/tty/serial/8250/8250_port.c:3321 console_emit_next_record kernel/printk/printk.c:3183 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 dump_unreclaimable_slab+0x112/0x150 mm/slab_common.c:1167 dump_header+0x3b8/0x4c0 mm/oom_kill.c:470 oom_kill_process+0x3ab/0x970 mm/oom_kill.c:1031 out_of_memory+0x1141/0x1410 mm/oom_kill.c:1151 __alloc_pages_may_oom+0x1ea/0x330 mm/page_alloc.c:4111 __alloc_pages_slowpath+0x6c2/0xd40 mm/page_alloc.c:4909 __alloc_frozen_pages_noprof+0x322/0x380 mm/page_alloc.c:5234 alloc_pages_mpol+0x235/0x490 mm/mempolicy.c:2490 alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline] alloc_pages_noprof+0xac/0x2a0 mm/mempolicy.c:2581 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2591 filemap_alloc_folio_noprof+0x111/0x470 mm/filemap.c:1014 __filemap_get_folio_mpol+0x3fc/0xb00 mm/filemap.c:2012 __filemap_get_folio include/linux/pagemap.h:763 [inline] filemap_fault+0x98e/0x1300 mm/filemap.c:3565 __do_fault+0x138/0x2a0 mm/memory.c:5474 do_read_fault mm/memory.c:5909 [inline] do_fault mm/memory.c:6043 [inline] do_pte_missing+0x2093/0x33f0 mm/memory.c:4566 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault mm/memory.c:6565 [inline] handle_mm_fault+0x1bf2/0x3170 mm/memory.c:6734 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0023:0xf70ee138 Code: Unable to access opcode bytes at 0xf70ee10e. RSP: 002b:00000000f75cfa20 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 00000000bfffffff RDX: 000000000c230000 RSI: 000000000000003e RDI: 000000000c230000 RBP: 00000000f7fd5610 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000