================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x1f9/0x2a0 net/bluetooth/l2cap_sock.c:1484 Read of size 8 at addr ffff88807c613548 by task kworker/u5:0/12575 CPU: 0 PID: 12575 Comm: kworker/u5:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci1 hci_rx_work Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 l2cap_sock_new_connection_cb+0x1f9/0x2a0 net/bluetooth/l2cap_sock.c:1484 l2cap_connect_cfm+0x375/0x1070 net/bluetooth/l2cap_core.c:7259 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1999 le_conn_complete_evt+0xfdc/0x1540 net/bluetooth/hci_event.c:5786 hci_le_conn_complete_evt+0x187/0x440 net/bluetooth/hci_event.c:5812 hci_event_func net/bluetooth/hci_event.c:7454 [inline] hci_event_packet+0x7ba/0x1270 net/bluetooth/hci_event.c:7509 hci_rx_work+0x43a/0xd60 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Allocated by task 12575: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc+0xb4/0x230 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2096 sk_alloc+0x3a/0x360 net/core/sock.c:2152 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1881 [inline] l2cap_sock_new_connection_cb+0xe2/0x2a0 net/bluetooth/l2cap_sock.c:1469 l2cap_connect_cfm+0x375/0x1070 net/bluetooth/l2cap_core.c:7259 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1999 le_conn_complete_evt+0xfdc/0x1540 net/bluetooth/hci_event.c:5786 hci_le_conn_complete_evt+0x187/0x440 net/bluetooth/hci_event.c:5812 hci_event_func net/bluetooth/hci_event.c:7454 [inline] hci_event_packet+0x7ba/0x1270 net/bluetooth/hci_event.c:7509 hci_rx_work+0x43a/0xd60 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Freed by task 26390: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 sk_prot_free net/core/sock.c:2135 [inline] __sk_destruct+0x4e0/0x660 net/core/sock.c:2230 l2cap_sock_cleanup_listen+0xda/0x3e0 net/bluetooth/l2cap_sock.c:1449 l2cap_sock_release+0x6a/0x1e0 net/bluetooth/l2cap_sock.c:1410 __sock_release net/socket.c:659 [inline] sock_close+0xbd/0x230 net/socket.c:1420 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x153/0x950 kernel/rcu/tree.c:2837 netlink_release+0x1702/0x1ad0 net/netlink/af_netlink.c:801 __sock_release net/socket.c:659 [inline] sock_close+0xbd/0x230 net/socket.c:1420 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x153/0x950 kernel/rcu/tree.c:2837 netlink_release+0x1702/0x1ad0 net/netlink/af_netlink.c:801 __sock_release net/socket.c:659 [inline] sock_close+0xbd/0x230 net/socket.c:1420 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807c613000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1352 bytes inside of freed 2048-byte region [ffff88807c613000, ffff88807c613800) The buggy address belongs to the physical page: page:ffffea0001f18400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c610 head:ffffea0001f18400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c42000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080080008 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5126, tgid 5126 (klogd), ts 91087289041, free_ts 91083594026 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3191 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] syslog_print+0x104/0x630 kernel/printk/printk.c:1553 do_syslog+0x575/0x820 kernel/printk/printk.c:1732 __do_sys_syslog kernel/printk/printk.c:1824 [inline] __se_sys_syslog kernel/printk/printk.c:1822 [inline] __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1822 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 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:1154 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] __kmem_cache_alloc_node+0x13a/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node+0xa4/0x230 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] kzalloc_node include/linux/slab.h:732 [inline] qdisc_alloc+0x94/0xa50 net/sched/sch_generic.c:951 qdisc_create_dflt+0x63/0x430 net/sched/sch_generic.c:1012 attach_one_default_qdisc net/sched/sch_generic.c:1176 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2520 [inline] attach_default_qdiscs net/sched/sch_generic.c:1194 [inline] dev_activate+0x397/0x11a0 net/sched/sch_generic.c:1253 __dev_open+0x347/0x430 net/core/dev.c:1541 __dev_change_flags+0x211/0x6a0 net/core/dev.c:8716 Memory state around the buggy address: ffff88807c613400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c613480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807c613500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c613580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c613600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================