================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 Read of size 1 at addr ffff888032bc8418 by task syz.4.1465/14049 CPU: 0 UID: 0 PID: 14049 Comm: syz.4.1465 Tainted: G L syzkaller #0 PREEMPT_{RT,(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 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:574 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5844 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 rt_mutex_slowunlock+0xbf/0x8b0 kernel/locking/rtmutex.c:1430 kbd_keycode drivers/tty/vt/keyboard.c:1565 [inline] kbd_event+0x2f91/0x42f0 drivers/tty/vt/keyboard.c:1583 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2558 input_pass_values+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342 input_inject_event+0x1d7/0x320 drivers/input/input.c:424 evdev_write+0x328/0x4c0 drivers/input/evdev.c:528 vfs_write+0x2a3/0xba0 fs/read_write.c:686 ksys_write+0x156/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f03fe4fcdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f03fc72d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f03fe776090 RCX: 00007f03fe4fcdd9 RDX: 0000000000002250 RSI: 0000200000000040 RDI: 0000000000000007 RBP: 00007f03fe592d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f03fe776128 R14: 00007f03fe776090 R15: 00007fff3d66f0e8 Allocated by task 14048: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5432 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] alloc_tty_struct+0xa6/0x7b0 drivers/tty/tty_io.c:3102 tty_init_dev+0x59/0x4d0 drivers/tty/tty_io.c:1400 tty_open_by_driver drivers/tty/tty_io.c:2073 [inline] tty_open+0x86e/0xd80 drivers/tty/tty_io.c:2120 chrdev_open+0x4d0/0x5f0 fs/char_dev.c:411 do_dentry_open+0x83d/0x13e0 fs/open.c:947 vfs_open+0x3b/0x350 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2e43/0x38a0 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12654: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2700 [inline] slab_free mm/slub.c:6291 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6606 process_one_work+0x98b/0x1630 kernel/workqueue.c:3306 process_scheduled_works kernel/workqueue.c:3389 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3470 kthread+0x388/0x470 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 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2226 __queue_work+0xcfd/0x1010 kernel/workqueue.c:2381 queue_work_on+0x106/0x1d0 kernel/workqueue.c:2432 tty_release_struct+0xb8/0xd0 drivers/tty/tty_io.c:1692 tty_release+0xcb6/0x1710 drivers/tty/tty_io.c:1852 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xf3/0x4d0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888032bc8000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 1048 bytes inside of freed 2048-byte region [ffff888032bc8000, ffff888032bc8800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32bc8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88805c8bb001 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe2f3c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800080008 00000000f5000000 ffff88805c8bb001 head: 0080000000000040 ffff88813fe2f3c0 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 00000000f5000000 ffff88805c8bb001 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5615, tgid 5615 (syz-executor), ts 94502949015, free_ts 70243482031 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1861 prep_new_page mm/page_alloc.c:1869 [inline] get_page_from_freelist+0x27d6/0x2850 mm/page_alloc.c:3949 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5292 alloc_slab_page mm/slub.c:3289 [inline] allocate_slab+0x74/0x5e0 mm/slub.c:3404 new_slab mm/slub.c:3447 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7319 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4664 alloc_from_pcs mm/slub.c:4762 [inline] slab_alloc_node mm/slub.c:4896 [inline] __do_kmalloc_node mm/slub.c:5307 [inline] __kmalloc_node_track_caller_noprof+0x60b/0x7e0 mm/slub.c:5420 kmemdup_noprof+0x2b/0x70 mm/util.c:138 kmemdup_noprof include/linux/fortify-string.h:763 [inline] neigh_sysctl_register+0xae/0xa90 net/core/neighbour.c:3861 addrconf_sysctl_register+0xb3/0x1c0 net/ipv6/addrconf.c:7379 ipv6_add_dev+0xd82/0x1410 net/ipv6/addrconf.c:460 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3662 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline] call_netdevice_notifiers net/core/dev.c:2302 [inline] register_netdevice+0x1919/0x1f10 net/core/dev.c:11459 macvlan_common_newlink+0x12af/0x1a40 drivers/net/macvlan.c:1554 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3864 page last free pid 5460 tgid 5460 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1405 [inline] __free_frozen_pages+0x1075/0x11b0 mm/page_alloc.c:2946 __slab_free+0x252/0x2a0 mm/slub.c:5653 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4582 [inline] slab_alloc_node mm/slub.c:4911 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4918 vm_area_dup+0x2b/0x670 mm/vma_init.c:123 __split_vma+0x1e4/0xa30 mm/vma.c:516 vms_gather_munmap_vmas+0x32d/0x1380 mm/vma.c:1427 __mmap_setup mm/vma.c:2439 [inline] __mmap_region mm/vma.c:2753 [inline] mmap_region+0x945/0x2280 mm/vma.c:2857 do_mmap+0xc2f/0x10c0 mm/mmap.c:560 vm_mmap_pgoff+0x2cc/0x4f0 mm/util.c:581 ksys_mmap_pgoff+0x4e8/0x720 mm/mmap.c:606 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888032bc8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888032bc8380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888032bc8400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888032bc8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888032bc8500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================