================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock_bh include/linux/spinlock_api_smp.h:150 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:182 Read of size 1 at addr ffff8880528e75a0 by task syz.2.388/7127 CPU: 1 UID: 0 PID: 7127 Comm: syz.2.388 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 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:5842 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:182 spin_lock_bh include/linux/spinlock.h:348 [inline] bt_accept_unlink+0x63/0x2c0 net/bluetooth/af_bluetooth.c:262 l2cap_sock_teardown_cb+0x17e/0x490 net/bluetooth/l2cap_sock.c:1710 l2cap_chan_del+0x98/0x600 net/bluetooth/l2cap_core.c:687 l2cap_conn_del+0x2f2/0x520 net/bluetooth/l2cap_core.c:1825 hci_disconn_cfm include/net/bluetooth/hci_core.h:2154 [inline] hci_conn_hash_flush+0x105/0x260 net/bluetooth/hci_conn.c:2735 hci_dev_close_sync+0x7fc/0x10a0 net/bluetooth/hci_sync.c:5513 hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] hci_unregister_dev+0x232/0x5b0 net/bluetooth/hci_core.c:2678 vhci_release+0x16d/0x1c0 drivers/bluetooth/hci_vhci.c:700 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1009 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 get_signal+0x121b/0x12c0 kernel/signal.c:3046 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __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:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: ffff:0xfffffffa Code: Unable to access opcode bytes at 0xffffffd0. RSP: 002b:0000000000000000 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: 0000000000000004 RBX: 0000000000000005 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000040000000 R08: cf9d780a350b4549 R09: c7e58b697db8ef3d R10: d68d02d45a22dc24 R11: 19b4d49ef33da9ed R12: 39cb75b6fa6cb3d1 R13: a8d7b5dbf29d588f R14: 9b8908dcbb4f02b4 R15: 107b9d1451766018 Allocated by task 7842: 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+0x32d/0x660 mm/slub.c:5489 _kmalloc_noprof include/linux/slab.h:988 [inline] devinet_init_net+0x57/0x7c0 net/ipv4/devinet.c:2826 ops_init+0x35d/0x5d0 net/core/net_namespace.c:137 setup_net+0x118/0x350 net/core/net_namespace.c:446 copy_net_ns+0x4f9/0x720 net/core/net_namespace.c:579 create_new_namespaces+0x3f0/0x6b0 kernel/nsproxy.c:132 copy_namespaces+0x432/0x4b0 kernel/nsproxy.c:195 copy_process+0x1e89/0x4390 kernel/fork.c:2292 kernel_clone+0x2d7/0x940 kernel/fork.c:2748 __do_sys_clone kernel/fork.c:2889 [inline] __se_sys_clone kernel/fork.c:2873 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2873 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7842: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 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:2677 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x1c5/0x640 mm/slub.c:6692 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:252 setup_net+0x2f6/0x350 net/core/net_namespace.c:462 copy_net_ns+0x4f9/0x720 net/core/net_namespace.c:579 create_new_namespaces+0x3f0/0x6b0 kernel/nsproxy.c:132 copy_namespaces+0x432/0x4b0 kernel/nsproxy.c:195 copy_process+0x1e89/0x4390 kernel/fork.c:2292 kernel_clone+0x2d7/0x940 kernel/fork.c:2748 __do_sys_clone kernel/fork.c:2889 [inline] __se_sys_clone kernel/fork.c:2873 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2873 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880528e7000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1440 bytes inside of freed 2048-byte region [ffff8880528e7000, ffff8880528e7800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880528e0000 pfn:0x528e0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b002000 ffffea0001e5ec10 ffffea0001e0fc10 raw: ffff8880528e0000 0000000800080005 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b002000 ffffea0001e5ec10 ffffea0001e0fc10 head: ffff8880528e0000 0000000800080005 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 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 9, tgid 9 (kworker/0:0), ts 91510880899, free_ts 26482671832 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3380 new_slab mm/slub.c:3426 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x2bf/0x6b0 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_node_track_caller_noprof+0x557/0x730 mm/slub.c:5471 kmalloc_reserve net/core/skbuff.c:637 [inline] __alloc_skb+0x2bd/0x7a0 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1384 [inline] mld_newpack+0x165/0xcb0 net/ipv6/mcast.c:1789 add_grhead net/ipv6/mcast.c:1900 [inline] add_grec+0x119f/0x19d0 net/ipv6/mcast.c:2039 mld_send_cr net/ipv6/mcast.c:2164 [inline] mld_ifc_work+0x6f1/0xd60 net/ipv6/mcast.c:2710 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] free_pages_prepare+0x960/0xa60 mm/page_alloc.c:1451 __free_contig_range_common+0x174/0x340 mm/page_alloc.c:6897 destroy_args+0x4e5/0x570 mm/debug_vm_pgtable.c:993 debug_vm_pgtable+0x3f8/0x410 mm/debug_vm_pgtable.c:1368 do_one_initcall+0x250/0x870 init/main.c:1347 do_initcall_level+0x10a/0x1a0 init/main.c:1409 do_initcalls+0x59/0xa0 init/main.c:1425 kernel_init_freeable+0x29d/0x3e0 init/main.c:1658 kernel_init+0x1d/0x1d0 init/main.c:1548 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff8880528e7480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880528e7500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880528e7580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880528e7600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880528e7680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================