================================================================== BUG: KASAN: slab-use-after-free in rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 Read of size 1 at addr ffff888033f2e7e8 by task syz.3.442/7231 CPU: 0 UID: 0 PID: 7231 Comm: syz.3.442 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 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 lock_acquire+[ 152.623774][ T7231] kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+[ 152.623774][ T7231] 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:263 l2cap_sock_teardown_cb+0x17e/0x490 net/bluetooth/l2cap_sock.c:1693 l2cap_chan_del+0x98/0x600 net/bluetooth/l2cap_core.c:659 l2cap_conn_del+0x2f2/0x520 net/bluetooth/l2cap_core.c:1797 hci_disconn_cfm include/net/bluetooth/hci_core.h:2152 [inline] hci_conn_hash_flush+0x105/0x260 net/bluetooth/hci_conn.c:2733 hci_dev_close_sync+0x7fc/0x10a0 net/bluetooth/hci_sync.c:5379 hci_dev_do_close net/bluetooth/hci_core.c:502 [inline] hci_dev_close+0x108/0x260 net/bluetooth/hci_core.c:527 sock_do_ioctl+0x101/0x320 net/socket.c:1315 sock_ioctl+0x57d/0x7f0 net/socket.c:1436 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/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 RIP: 0033:0x7f4b2105de59 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:00007f4b1f2b6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4b212e5fa0 RCX: 00007f4b2105de59 RDX: 0000000000000000 RSI: 00000000400448ca RDI: 000000000000000c RBP: 00007f4b210f3e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4b212e6038 R14: 00007f4b212e5fa0 R15: 00007fff8ceab578 Allocated by task 7014: 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:5336 [inline] __kmalloc_noprof+0x415/0x790 mm/slub.c:5361 _kmalloc_noprof include/linux/slab.h:973 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2252 sk_alloc+0x3a/0x390 net/core/sock.c:2308 bt_sock_alloc+0x3b/0x340 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1984 [inline] l2cap_sock_create+0x147/0x330 net/bluetooth/l2cap_sock.c:2026 bt_sock_create+0x163/0x240 net/bluetooth/af_bluetooth.c:132 __sock_create+0x4e8/0x960 net/socket.c:1666 sock_create net/socket.c:1724 [inline] __sys_socket_create net/socket.c:1761 [inline] __sys_socket+0xd9/0x320 net/socket.c:1808 __do_sys_socket net/socket.c:1822 [inline] __se_sys_socket net/socket.c:1820 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1820 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 7013: 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:2705 [inline] slab_free mm/slub.c:6381 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6696 sk_prot_free net/core/sock.c:2291 [inline] __sk_destruct+0x754/0x9e0 net/core/sock.c:2391 l2cap_sock_release+0x1b3/0x250 net/bluetooth/l2cap_sock.c:1479 __sock_release+0xa0/0x1f0 net/socket.c:714 sock_close+0x1c/0x30 net/socket.c:1516 __fput+0x42a/0xa80 fs/file_table.c:512 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:70 [inline] exit_to_user_mode_loop+0x1fa/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 The buggy address belongs to the object at ffff888033f2e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2024 bytes inside of freed 4096-byte region [ffff888033f2e000, ffff888033f2f000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33f28 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 ffff88813feaa140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813feaa140 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 4981, tgid 4981 (udevadm), ts 28323410088 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+0x264c/0x26c0 mm/page_alloc.c:3949 __alloc_frozen_pages_noprof+0x1a6/0x390 mm/page_alloc.c:5322 alloc_slab_page mm/slub.c:3294 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3408 new_slab mm/slub.c:3454 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7314 refill_sheaf mm/slub.c:2832 [inline] __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4697 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4907 [inline] __do_kmalloc_node mm/slub.c:5335 [inline] __kmalloc_noprof+0x543/0x790 mm/slub.c:5361 _kmalloc_noprof include/linux/slab.h:973 [inline] tomoyo_realpath_from_path+0xef/0x640 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827 security_inode_getattr+0x12b/0x310 security/security.c:1895 vfs_getattr fs/stat.c:259 [inline] vfs_fstat fs/stat.c:281 [inline] __do_sys_newfstat fs/stat.c:551 [inline] __se_sys_newfstat fs/stat.c:546 [inline] __x64_sys_newfstat+0x133/0x270 fs/stat.c:546 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 4979 tgid 4979 ts 28318473987 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1408 [inline] __free_frozen_pages+0x10de/0x11c0 mm/page_alloc.c:2952 __slab_free+0x252/0x2a0 mm/slub.c:5743 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:4606 [inline] slab_alloc_node mm/slub.c:4919 [inline] kmem_cache_alloc_node_noprof+0x3f4/0x660 mm/slub.c:4991 __alloc_skb+0x1d7/0x7a0 net/core/skbuff.c:704 netlink_sendmsg+0x5d4/0xb40 net/netlink/af_netlink.c:1875 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:785 __sock_sendmsg net/socket.c:800 [inline] ____sys_sendmsg+0x565/0x870 net/socket.c:2702 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2756 __sys_sendmsg net/socket.c:2788 [inline] __do_sys_sendmsg net/socket.c:2793 [inline] __se_sys_sendmsg net/socket.c:2791 [inline] __x64_sys_sendmsg+0x1b7/0x290 net/socket.c:2791 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: ffff888033f2e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888033f2e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888033f2e780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888033f2e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888033f2e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================