================================================================== BUG: KASAN: slab-use-after-free in rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 Read of size 1 at addr ffff8880591587e8 by task syz.2.264[ 584.818859][T12817] Read of size 1 at addr ffff8880591587e8 by task syz.2.2647/12817 CPU: 1 UID: 0 PID: 12817 Comm: syz.2.2647 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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 rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 spin_lock_bh include/linux/spinlock_rt.h:90 [inline] bt_accept_unlink+0x7d/0x2f0 net/bluetooth/af_bluetooth.c:262 l2cap_sock_teardown_cb+0x17e/0x490 net/bluetooth/l2cap_sock.c:1692 l2cap_chan_del+0x99/0x600 net/bluetooth/l2cap_core.c:659 l2cap_conn_del+0x33d/0x570 net/bluetooth/l2cap_core.c:1803 hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] hci_conn_hash_flush+0x10d/0x260 net/bluetooth/hci_conn.c:2733 hci_dev_close_sync+0x85d/0x1150 net/bluetooth/hci_sync.c:5405 hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] hci_unregister_dev+0x232/0x5b0 net/bluetooth/hci_core.c:2678 vhci_release+0x155/0x1b0 drivers/bluetooth/hci_vhci.c:700 __fput+0x461/0xa70 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+0x70f/0x22c0 kernel/exit.c:1004 do_group_exit+0x21b/0x2d0 kernel/exit.c:1147 get_signal+0x1284/0x1330 kernel/signal.c:3038 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x710 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: 0033:0x7fd775b1d68e Code: Unable to access opcode bytes at 0x7fd775b1d664. RSP: 002b:00007fd773dadf58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fd773dae6c0 RCX: 00007fd775b1d68e RDX: 00007fd773dadfb0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fd775bf2d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd775dd6038 R14: 00007fd775dd5fa0 R15: 00007ffd17b4a138 Allocated by task 6102: 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] __do_kmalloc_node mm/slub.c:5357 [inline] __kmalloc_node_track_caller_noprof+0x3a7/0x820 mm/slub.c:5492 kmalloc_reserve net/core/skbuff.c:637 [inline] __alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1384 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x29f/0xbd0 drivers/net/netdevsim/dev.c:922 process_one_work+0x98b/0x1630 kernel/workqueue.c:3326 process_scheduled_works kernel/workqueue.c:3409 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3490 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 Freed by task 6102: 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:2699 [inline] slab_free mm/slub.c:6400 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6715 skb_kfree_head net/core/skbuff.c:1077 [inline] skb_free_head net/core/skbuff.c:1089 [inline] skb_release_data+0x828/0xa60 net/core/skbuff.c:1116 skb_release_all net/core/skbuff.c:1191 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1205 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline] nsim_dev_trap_report_work+0x809/0xbd0 drivers/net/netdevsim/dev.c:922 process_one_work+0x98b/0x1630 kernel/workqueue.c:3326 process_scheduled_works kernel/workqueue.c:3409 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3490 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 The buggy address belongs to the object at ffff888059158000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2024 bytes inside of freed 4096-byte region [ffff888059158000, ffff888059159000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x59158 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe31140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe31140 dead000000000100 dead000000000122 head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5898, tgid 5897 (syz.2.41), ts 100253059562, free_ts 100166097248 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+0x265c/0x26e0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3288 [inline] allocate_slab+0x76/0x5d0 mm/slub.c:3406 new_slab mm/slub.c:3452 [inline] refill_objects+0x2d9/0x350 mm/slub.c:7333 refill_sheaf mm/slub.c:2826 [inline] __pcs_replace_empty_main+0x331/0x690 mm/slub.c:4698 alloc_from_pcs mm/slub.c:4796 [inline] slab_alloc_node mm/slub.c:4929 [inline] __do_kmalloc_node mm/slub.c:5356 [inline] __kmalloc_noprof+0x56d/0x7e0 mm/slub.c:5382 _kmalloc_noprof include/linux/slab.h:973 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x246/0x630 security/tomoyo/file.c:728 security_file_ioctl+0xc3/0x2a0 security/security.c:2512 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:583 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 page last free pid 5895 tgid 5895 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x10af/0x1190 mm/page_alloc.c:2950 __slab_free+0x252/0x2a0 mm/slub.c:5762 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:4614 [inline] slab_alloc_node mm/slub.c:4941 [inline] __do_kmalloc_node mm/slub.c:5356 [inline] __kmalloc_noprof+0x3b4/0x7e0 mm/slub.c:5382 _kmalloc_noprof include/linux/slab.h:973 [inline] _kzalloc_noprof include/linux/slab.h:1287 [inline] lsm_blob_alloc security/security.c:218 [inline] lsm_task_alloc security/security.c:270 [inline] security_task_alloc+0x4d/0x330 security/security.c:2785 copy_process+0x1c81/0x42e0 kernel/fork.c:2270 kernel_clone+0x2d7/0x940 kernel/fork.c:2746 __do_sys_clone3 kernel/fork.c:3048 [inline] __se_sys_clone3+0x33c/0x360 kernel/fork.c:3027 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 Memory state around the buggy address: ffff888059158680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888059158700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888059158780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888059158800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888059158880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================