watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.4.431:1599] CPU#0 Utilization every 22s during lockup: #1: 100% system, 0% softirq, 1% hardirq, 0% idle #2: 100% system, 1% softirq, 1% hardirq, 0% idle #3: 100% system, 0% softirq, 1% hardirq, 0% idle #4: 100% system, 1% softirq, 1% hardirq, 0% idle #5: 100% system, 0% softirq, 1% hardirq, 0% idle Modules linked in: CPU: 0 UID: 0 PID: 1599 Comm: syz.4.431 Not tainted 6.12.30-syzkaller-g2e58e85c038f #0 c5e7ad78b71ddb211d6a9cda70735ca8545dcbc5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 6f 05 48 89 de e8 e0 f9 51 00 5b 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc b8 5c ac b3 7b 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 48 8b 45 08 65 48 8b 0c 25 40 e9 04 00 65 RSP: 0018:ffffc900017179b8 EFLAGS: 00000202 RAX: 1ffff110281b5c53 RBX: ffffffffffffff28 RCX: dffffc0000000000 RDX: ffffc90003a0a000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90001717a10 R08: ffff888125cffb6f R09: 0000000000000000 R10: ffff888125cffb60 R11: ffffed1024b9ff6e R12: ffff888140daea80 R13: ffff88811075d440 R14: ffff888140dae1e0 R15: ffff888134462fc0 FS: 00007fc3d0c396c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3341fffc CR3: 0000000129040000 CR4: 00000000003526b0 DR0: 0000000000010001 DR1: 0000000000000002 DR2: 000000000000007f DR3: 0000000000000004 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: umount_tree+0xdfd/0xf70 fs/namespace.c:1807 attach_recursive_mnt+0x6df/0x21c0 fs/namespace.c:2548 graft_tree+0x157/0x1c0 fs/namespace.c:2683 do_loopback+0x364/0x4b0 fs/namespace.c:2798 path_mount+0x582/0x1050 fs/namespace.c:3840 do_mount fs/namespace.c:3859 [inline] __do_sys_mount fs/namespace.c:4069 [inline] __se_sys_mount+0x2bd/0x480 fs/namespace.c:4046 __x64_sys_mount+0xc3/0xf0 fs/namespace.c:4046 x64_sys_call+0x2021/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fc3cfd8e9a9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc3d0c39038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc3cffb6080 RCX: 00007fc3cfd8e9a9 RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000200000000240 RBP: 00007fc3cfe10ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000080700a R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fc3cffb6080 R15: 00007fff8ca28668 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.30-syzkaller-g2e58e85c038f #0 c5e7ad78b71ddb211d6a9cda70735ca8545dcbc5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:kasan_check_range+0x1ca/0x2a0 mm/kasan/generic.c:-1 Code: 4d 01 f3 49 8d 5d 07 4d 85 ed 49 0f 49 dd 48 83 e3 f8 49 29 dd 74 12 41 80 3b 00 0f 85 ab 00 00 00 49 ff c3 49 ff cd 75 ee 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 58 7b ac 03 cc 45 84 ff 75 61 41 f7 RSP: 0018:ffffc9000026f6a0 EFLAGS: 00000056 RAX: f300f204f1f1f101 RBX: ffffffff889dada0 RCX: ffffffff8587cb32 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff889dada0 RBP: ffffc9000026f6c0 R08: ffffffff889dada3 R09: 1ffffffff113b5b4 R10: dffffc0000000000 R11: fffffbfff113b5b5 R12: dffffc0000000000 R13: 0000000000000001 R14: fffffbfff113b5b5 R15: 1ffffffff113b5b4 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ac4e809be0 CR3: 000000011ef0a000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __kasan_check_write+0x18/0x20 mm/kasan/shadow.c:37 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock include/linux/spinlock.h:187 [inline] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xa2/0x150 kernel/locking/spinlock.c:162 uart_port_lock_irqsave include/linux/serial_core.h:718 [inline] serial8250_console_write+0x1e9/0x2130 drivers/tty/serial/8250/8250_port.c:3381 univ8250_console_write+0x6f/0xb0 drivers/tty/serial/8250/8250_core.c:396 console_emit_next_record kernel/printk/printk.c:3132 [inline] console_flush_all+0x5e3/0xaa0 kernel/printk/printk.c:3220 __console_flush_and_unlock kernel/printk/printk.c:3279 [inline] console_unlock+0xe9/0x270 kernel/printk/printk.c:3319 vprintk_emit+0x27c/0x640 kernel/printk/printk.c:2443 vprintk_default+0x2a/0x40 kernel/printk/printk.c:2458 vprintk+0x93/0xa0 kernel/printk/printk_safe.c:73 _printk+0xd0/0x120 kernel/printk/printk.c:2468 check_hung_task kernel/hung_task.c:171 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:256 [inline] watchdog+0x97c/0xed0 kernel/hung_task.c:423 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1616 Comm: syz-executor Tainted: G L 6.12.30-syzkaller-g2e58e85c038f #0 c5e7ad78b71ddb211d6a9cda70735ca8545dcbc5 Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x70 kernel/kcov.c:217 Code: 40 e9 04 00 65 8b 15 2c 3e 7f 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 ec 0b 00 00 00 74 2c 8b 91 c8 0b 00 00 <83> fa 02 75 21 48 8b 91 d0 0b 00 00 48 8b 32 48 8d 7e 01 8b 89 cc RSP: 0018:ffffc900109176b8 EFLAGS: 00000246 RAX: ffffffff81e1ce96 RBX: 0000000000000000 RCX: ffff88810b789300 RDX: 0000000000000000 RSI: 0000000004b201fe RDI: 0000000000000000 RBP: ffffc900109176b8 R08: 000000001f8e4705 R09: 000000008aee3756 R10: 000000000000000e R11: ffffffff81740950 R12: 0000000004b201fe R13: 1ffff110216f1329 R14: dffffc0000000000 R15: ffff8881078f8268 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b451249b98 CR3: 00000000072a8000 CR4: 00000000003526b0 DR0: 0000000000010001 DR1: 0000000000000002 DR2: 000000000000007f DR3: 0000000000000004 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __update_page_owner_free_handle mm/page_owner.c:286 [inline] __reset_page_owner+0x126/0x450 mm/page_owner.c:316 reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1321 [inline] free_unref_page+0xae5/0xdd0 mm/page_alloc.c:2810 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5273 vfree+0x3bf/0x580 mm/vmalloc.c:3388 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x2c/0x70 kernel/kcov.c:535 __fput+0x1fb/0xa00 fs/file_table.c:431 ____fput+0x20/0x30 fs/file_table.c:459 task_work_run+0x1e3/0x250 kernel/task_work.c:240 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9b4/0x2630 kernel/exit.c:944 do_group_exit+0x22a/0x300 kernel/exit.c:1094 get_signal+0x139d/0x14f0 kernel/signal.c:2934 arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7ff312b8e5ab Code: Unable to access opcode bytes at 0x7ff312b8e581. RSP: 002b:00007ffd506a36c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffff4 RBX: 0000000000080000 RCX: 00007ff312b8e5ab RDX: 0000000000080000 RSI: ffffffff80086301 RDI: 00000000000000dd RBP: 00007ff312db6498 R08: 00000000000000da R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000