================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x107/0x7c40 kernel/locking/lockdep.c:4933 Read of size 8 at addr ffff88807a1c1540 by task syz.2.21/4438 CPU: 0 PID: 4438 Comm: syz.2.21 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 __lock_acquire+0x107/0x7c40 kernel/locking/lockdep.c:4933 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] bt_accept_unlink+0x5f/0x290 net/bluetooth/af_bluetooth.c:262 l2cap_sock_teardown_cb+0x1af/0x380 net/bluetooth/l2cap_sock.c:1668 l2cap_chan_del+0xa8/0x520 net/bluetooth/l2cap_core.c:690 l2cap_conn_del+0x346/0x5d0 net/bluetooth/l2cap_core.c:1830 hci_disconn_cfm include/net/bluetooth/hci_core.h:1837 [inline] hci_conn_hash_flush+0x113/0x290 net/bluetooth/hci_conn.c:2532 hci_dev_close_sync+0x9e5/0x1120 net/bluetooth/hci_sync.c:5284 hci_dev_do_close net/bluetooth/hci_core.c:528 [inline] hci_dev_close+0x104/0x1f0 net/bluetooth/hci_core.c:553 sock_do_ioctl+0xfb/0x320 net/socket.c:1202 sock_ioctl+0x48a/0x700 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f98b359e0d9 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:00007f98b43f3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f98b3825fa0 RCX: 00007f98b359e0d9 RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000004 RBP: 00007f98b3635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f98b3826038 R14: 00007f98b3825fa0 R15: 00007ffee03371c8 Allocated by task 4372: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc+0xb3/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2057 sk_alloc+0x36/0x330 net/core/sock.c:2113 bt_sock_alloc+0x37/0x350 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1937 [inline] l2cap_sock_create+0x13e/0x2c0 net/bluetooth/l2cap_sock.c:1975 bt_sock_create+0x155/0x220 net/bluetooth/af_bluetooth.c:132 __sock_create+0x49a/0x940 net/socket.c:1550 sock_create net/socket.c:1606 [inline] __sys_socket_create net/socket.c:1643 [inline] __sys_socket+0xc4/0x190 net/socket.c:1671 __do_sys_socket net/socket.c:1684 [inline] __se_sys_socket net/socket.c:1682 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1682 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 4372: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x200 mm/slub.c:3700 sk_prot_free net/core/sock.c:2096 [inline] __sk_destruct+0x4bb/0x650 net/core/sock.c:2182 l2cap_sock_release+0x169/0x1e0 net/bluetooth/l2cap_sock.c:1449 __sock_release net/socket.c:654 [inline] sock_close+0xbf/0x210 net/socket.c:1400 __fput+0x20a/0x8b0 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807a1c1000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1344 bytes inside of 2048-byte region [ffff88807a1c1000, ffff88807a1c1800) The buggy address belongs to the physical page: page:ffffea0001e87000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7a1c0 head:ffffea0001e87000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888017442000 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x152a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 4372, tgid 4370 (syz.0.1), ts 89030278491, free_ts 89028432326 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] l2cap_chan_create+0x4c/0x760 net/bluetooth/l2cap_core.c:451 l2cap_sock_create+0x115/0x2c0 net/bluetooth/l2cap_sock.c:1971 bt_sock_create+0x155/0x220 net/bluetooth/af_bluetooth.c:132 __sock_create+0x49a/0x940 net/socket.c:1550 sock_create net/socket.c:1606 [inline] __sys_socket_create net/socket.c:1643 [inline] __sys_socket+0xc4/0x190 net/socket.c:1671 __do_sys_socket net/socket.c:1684 [inline] __se_sys_socket net/socket.c:1682 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1682 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1487 [inline] free_pcp_prepare mm/page_alloc.c:1537 [inline] free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x188/0x1e0 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] __kmem_cache_alloc_node+0x19d/0x270 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node+0xa2/0x240 mm/slab_common.c:943 kmalloc_array_node include/linux/slab.h:676 [inline] kcalloc_node include/linux/slab.h:681 [inline] memcg_alloc_slab_cgroups+0x81/0x120 mm/memcontrol.c:2889 account_slab mm/slab.h:635 [inline] allocate_slab mm/slub.c:1962 [inline] new_slab+0xc3/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x111/0x2f0 mm/slub.c:3383 alloc_pid+0x9d/0xc10 kernel/pid.c:180 copy_process+0x1c37/0x40c0 kernel/fork.c:2375 Memory state around the buggy address: ffff88807a1c1400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a1c1480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807a1c1500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807a1c1580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a1c1600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================