================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x1f9/0x2b0 net/bluetooth/l2cap_sock.c:1484 Read of size 8 at addr ffff88806087b548 by task kworker/u5:2/5773 CPU: 1 PID: 5773 Comm: kworker/u5:2 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+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x220 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 l2cap_sock_new_connection_cb+0x1f9/0x2b0 net/bluetooth/l2cap_sock.c:1484 l2cap_connect_cfm+0x375/0x1030 net/bluetooth/l2cap_core.c:7259 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1999 le_conn_complete_evt+0xfb5/0x1500 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+0x795/0x1210 net/bluetooth/hci_event.c:7509 hci_rx_work+0x43a/0xd80 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 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 5773: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc+0xb4/0x240 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+0xe2/0x2b0 net/bluetooth/l2cap_sock.c:1469 l2cap_connect_cfm+0x375/0x1030 net/bluetooth/l2cap_core.c:7259 hci_connect_cfm+0x8f/0x130 include/net/bluetooth/hci_core.h:1999 le_conn_complete_evt+0xfb5/0x1500 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+0x795/0x1210 net/bluetooth/hci_event.c:7509 hci_rx_work+0x43a/0xd80 net/bluetooth/hci_core.c:4018 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 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 15718: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 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:1421 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 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+0xf6/0x180 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+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x158/0x930 kernel/rcu/tree.c:2837 netlink_release+0x16b4/0x1a80 net/netlink/af_netlink.c:801 __sock_release net/socket.c:659 [inline] sock_close+0xbd/0x230 net/socket.c:1421 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 __do_sys_exit kernel/exit.c:991 [inline] __se_sys_exit kernel/exit.c:989 [inline] __ia32_sys_exit+0x0/0x40 kernel/exit.c:989 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88806087b000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1352 bytes inside of freed 2048-byte region [ffff88806087b000, ffff88806087b800) The buggy address belongs to the physical page: page:ffffea0001821e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x60878 head:ffffea0001821e00 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 ffff888017842000 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 11266, tgid 11264 (+}[@), ts 289492076170, free_ts 289421469726 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2e0 mm/slub.c:2081 ___slab_alloc+0xc6d/0x1300 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+0x1a2/0x260 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1284 [inline] nlmsg_new include/net/netlink.h:1010 [inline] audit_buffer_alloc kernel/audit.c:1796 [inline] audit_log_start+0x152/0x830 kernel/audit.c:1914 audit_seccomp+0x63/0x180 kernel/auditsc.c:3007 seccomp_log kernel/seccomp.c:1003 [inline] __seccomp_filter+0xa49/0x1b70 kernel/seccomp.c:1290 syscall_trace_enter+0xa7/0x150 kernel/entry/common.c:72 do_syscall_64+0x28/0xb0 arch/x86/entry/common.c:77 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+0x7ce/0x8e0 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+0x31d/0x410 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3519 getname_flags+0xbb/0x500 fs/namei.c:140 vfs_fstatat+0x111/0x1b0 fs/stat.c:298 __do_sys_newfstatat fs/stat.c:463 [inline] __se_sys_newfstatat fs/stat.c:457 [inline] __x64_sys_newfstatat+0x117/0x190 fs/stat.c:457 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff88806087b400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806087b480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806087b500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806087b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806087b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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