================================================================== BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x68b/0x1090 net/bluetooth/l2cap_core.c:7240 Read of size 8 at addr ffff88807c1aa480 by task kworker/u9:1/21424 CPU: 1 UID: 0 PID: 21424 Comm: kworker/u9:1 Not tainted 6.14.0-rc4-syzkaller-00090-gdd83757f6e68 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: hci5 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x16e/0x5b0 mm/kasan/report.c:521 kasan_report+0x143/0x180 mm/kasan/report.c:634 l2cap_connect_cfm+0x68b/0x1090 net/bluetooth/l2cap_core.c:7240 hci_connect_cfm+0x164/0x240 include/net/bluetooth/hci_core.h:2051 le_conn_complete_evt+0xda8/0x1360 net/bluetooth/hci_event.c:5763 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5789 hci_event_func net/bluetooth/hci_event.c:7470 [inline] hci_event_packet+0xa56/0x1540 net/bluetooth/hci_event.c:7525 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4015 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 21424: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4325 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] l2cap_chan_create+0x50/0x760 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1887 [inline] l2cap_sock_new_connection_cb+0x181/0x2b0 net/bluetooth/l2cap_sock.c:1469 l2cap_connect_cfm+0x338/0x1090 net/bluetooth/l2cap_core.c:7223 hci_connect_cfm+0x164/0x240 include/net/bluetooth/hci_core.h:2051 le_conn_complete_evt+0xda8/0x1360 net/bluetooth/hci_event.c:5763 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5789 hci_event_func net/bluetooth/hci_event.c:7470 [inline] hci_event_packet+0xa56/0x1540 net/bluetooth/hci_event.c:7525 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4015 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 21618: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x196/0x430 mm/slub.c:4757 l2cap_sock_cleanup_listen+0xed/0x3c0 net/bluetooth/l2cap_sock.c:1452 l2cap_sock_release+0x5d/0x1d0 net/bluetooth/l2cap_sock.c:1412 __sock_release net/socket.c:647 [inline] sock_close+0xbe/0x240 net/socket.c:1398 __fput+0x3eb/0x9f0 fs/file_table.c:464 task_work_run+0x251/0x310 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807c1aa000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff88807c1aa000, ffff88807c1aa800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c1a8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b042000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b042000 dead000000000100 dead000000000122 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001f06a01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5834, tgid 5834 (syz-executor), ts 73741212425, free_ts 73725078845 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2587 new_slab mm/slub.c:2640 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826 __slab_alloc+0x58/0xa0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_noprof+0x2e6/0x4c0 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] sk_prot_alloc+0xe0/0x210 net/core/sock.c:2181 sk_alloc+0x38/0x370 net/core/sock.c:2234 __netlink_create+0x65/0x260 net/netlink/af_netlink.c:629 netlink_create+0x3ab/0x560 net/netlink/af_netlink.c:687 __sock_create+0x4c2/0xa30 net/socket.c:1548 sock_create net/socket.c:1606 [inline] __sys_socket_create net/socket.c:1643 [inline] __sys_socket+0x150/0x3c0 net/socket.c:1690 __do_sys_socket net/socket.c:1704 [inline] __se_sys_socket net/socket.c:1702 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1702 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 page last free pid 5834 tgid 5834 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_lru_noprof+0x1dd/0x390 mm/slub.c:4183 __d_alloc+0x31/0x740 fs/dcache.c:1664 d_alloc fs/dcache.c:1743 [inline] d_alloc_parallel+0xdf/0x1630 fs/dcache.c:2507 __lookup_slow+0x117/0x400 fs/namei.c:1778 lookup_one_len+0x1ef/0x300 fs/namei.c:2907 start_creating+0x187/0x310 fs/debugfs/inode.c:391 __debugfs_create_file+0x7d/0x500 fs/debugfs/inode.c:437 debugfs_create_file_full+0x40/0x60 fs/debugfs/inode.c:474 nsim_create+0x430/0xab0 drivers/net/netdevsim/netdev.c:995 Memory state around the buggy address: ffff88807c1aa380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c1aa400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807c1aa480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c1aa500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c1aa580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================