================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_new_connection_cb+0x22a/0x240 net/bluetooth/l2cap_sock.c:1484 Read of size 8 at addr ffff8880529b7580 by task kworker/u9:1/5130 CPU: 1 UID: 0 PID: 5130 Comm: kworker/u9:1 Not tainted 6.14.0-rc4-syzkaller-00242-g7a5668899f54 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: hci2 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xd9/0x110 mm/kasan/report.c:634 l2cap_sock_new_connection_cb+0x22a/0x240 net/bluetooth/l2cap_sock.c:1484 l2cap_connect_cfm+0x85f/0xf10 net/bluetooth/l2cap_core.c:7228 hci_connect_cfm include/net/bluetooth/hci_core.h:2051 [inline] le_conn_complete_evt+0x168d/0x1da0 net/bluetooth/hci_event.c:5763 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5789 hci_le_meta_evt+0x2e2/0x5d0 net/bluetooth/hci_event.c:7162 hci_event_func net/bluetooth/hci_event.c:7470 [inline] hci_event_packet+0x666/0x1180 net/bluetooth/hci_event.c:7525 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4015 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 5130: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4294 [inline] __kmalloc_noprof+0x21c/0x510 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2181 sk_alloc+0x36/0xc20 net/core/sock.c:2234 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1878 l2cap_sock_new_connection_cb+0x101/0x240 net/bluetooth/l2cap_sock.c:1469 l2cap_connect_cfm+0x85f/0xf10 net/bluetooth/l2cap_core.c:7228 hci_connect_cfm include/net/bluetooth/hci_core.h:2051 [inline] le_conn_complete_evt+0x168d/0x1da0 net/bluetooth/hci_event.c:5763 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5789 hci_le_meta_evt+0x2e2/0x5d0 net/bluetooth/hci_event.c:7162 hci_event_func net/bluetooth/hci_event.c:7470 [inline] hci_event_packet+0x666/0x1180 net/bluetooth/hci_event.c:7525 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4015 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 11264: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 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+0x2c4/0x4d0 mm/slub.c:4757 sk_prot_free net/core/sock.c:2217 [inline] __sk_destruct+0x5ef/0x6f0 net/core/sock.c:2312 sk_destruct+0xc2/0xf0 net/core/sock.c:2340 __sk_free+0xf4/0x3e0 net/core/sock.c:2351 sk_free+0x6a/0x90 net/core/sock.c:2362 sock_put include/net/sock.h:1914 [inline] l2cap_sock_kill net/bluetooth/l2cap_sock.c:1252 [inline] l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1237 l2cap_sock_cleanup_listen+0x3d/0x2a0 net/bluetooth/l2cap_sock.c:1449 l2cap_sock_release+0x5c/0x210 net/bluetooth/l2cap_sock.c:1412 __sock_release+0xb0/0x270 net/socket.c:647 sock_close+0x1c/0x30 net/socket.c:1398 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 get_signal+0x1d3/0x26c0 kernel/signal.c:2809 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880529b7000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1408 bytes inside of freed 2048-byte region [ffff8880529b7000, ffff8880529b7800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x529b0 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 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b042000 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00014a6c01 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 5814, tgid 5814 (syz-executor), ts 61091184961, free_ts 61061194532 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab mm/slub.c:2587 [inline] new_slab+0x23d/0x330 mm/slub.c:2640 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826 __slab_alloc.constprop.0+0x56/0xb0 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_node_noprof+0x2f0/0x510 mm/slub.c:4300 kmalloc_node_noprof include/linux/slab.h:928 [inline] qdisc_alloc+0xbb/0xc50 net/sched/sch_generic.c:947 qdisc_create_dflt+0x73/0x430 net/sched/sch_generic.c:1009 attach_one_default_qdisc net/sched/sch_generic.c:1175 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2590 [inline] attach_default_qdiscs net/sched/sch_generic.c:1193 [inline] dev_activate+0x63a/0x12b0 net/sched/sch_generic.c:1252 __dev_open+0x3e4/0x540 net/core/dev.c:1644 __dev_change_flags+0x561/0x720 net/core/dev.c:9254 dev_change_flags+0x8f/0x160 net/core/dev.c:9326 do_setlink.constprop.0+0x699/0x3f80 net/core/rtnetlink.c:3118 rtnl_changelink net/core/rtnetlink.c:3733 [inline] __rtnl_newlink net/core/rtnetlink.c:3885 [inline] rtnl_newlink+0x1306/0x1d60 net/core/rtnetlink.c:4022 page last free pid 5817 tgid 5817 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660 __put_partials+0x14c/0x170 mm/slub.c:3153 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 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] __kmalloc_cache_noprof+0x243/0x410 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] ref_tracker_alloc+0x17c/0x5b0 lib/ref_tracker.c:203 __netdev_tracker_alloc include/linux/netdevice.h:4282 [inline] netdev_hold include/linux/netdevice.h:4311 [inline] netdev_hold include/linux/netdevice.h:4306 [inline] netdev_queue_add_kobject net/core/net-sysfs.c:1817 [inline] netdev_queue_update_kobjects+0x24c/0x5b0 net/core/net-sysfs.c:1872 register_queue_kobjects net/core/net-sysfs.c:1934 [inline] netdev_register_kobject+0x28c/0x3a0 net/core/net-sysfs.c:2174 register_netdevice+0x147b/0x1eb0 net/core/dev.c:10943 team_newlink+0x92/0x160 drivers/net/team/team_core.c:2228 rtnl_newlink_create net/core/rtnetlink.c:3796 [inline] __rtnl_newlink net/core/rtnetlink.c:3907 [inline] rtnl_newlink+0xb95/0x1d60 net/core/rtnetlink.c:4022 rtnetlink_rcv_msg+0x95b/0xea0 net/core/rtnetlink.c:6912 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2533 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1882 Memory state around the buggy address: ffff8880529b7480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880529b7500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880529b7580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880529b7600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880529b7680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================