================================================================== BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1639 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0xde7/0xf80 net/bluetooth/l2cap_core.c:7414 Read of size 8 at addr ffff88802bde2480 by task kworker/u9:2/27646 CPU: 1 UID: 0 PID: 27646 Comm: kworker/u9:2 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci4 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 l2cap_conn_ready net/bluetooth/l2cap_core.c:1639 [inline] l2cap_connect_cfm+0xde7/0xf80 net/bluetooth/l2cap_core.c:7414 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5847 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5873 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7473 hci_event_func net/bluetooth/hci_event.c:7781 [inline] hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7838 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 27646: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] l2cap_chan_create+0x44/0x940 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc.constprop.0+0xf5/0x1e0 net/bluetooth/l2cap_sock.c:1934 l2cap_sock_new_connection_cb+0x101/0x260 net/bluetooth/l2cap_sock.c:1510 l2cap_connect_cfm+0x4e2/0xf80 net/bluetooth/l2cap_core.c:7397 hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline] le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5847 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5873 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7473 hci_event_func net/bluetooth/hci_event.c:7781 [inline] hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7838 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 29936: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1f6/0x6b0 mm/slub.c:6483 l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_chan_put+0x235/0x300 net/bluetooth/l2cap_core.c:516 l2cap_sock_cleanup_listen+0x4d/0x2d0 net/bluetooth/l2cap_sock.c:1493 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1451 __sock_release+0xb3/0x260 net/socket.c:662 sock_close+0x1c/0x30 net/socket.c:1455 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802bde2000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff88802bde2000, ffff88802bde2800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bde0 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 ffff88813fe41000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe41000 dead000000000100 dead000000000122 head: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000af7801 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 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 11053, tgid 11053 (kworker/1:7), ts 476562400968, free_ts 476232334899 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab mm/slub.c:3481 [inline] new_slab+0xa6/0x6b0 mm/slub.c:3539 refill_objects+0x26b/0x400 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kmalloc_node_track_caller_noprof+0x694/0x850 mm/slub.c:5368 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:635 __alloc_skb+0x185/0x710 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1775 add_grhead+0x299/0x340 net/ipv6/mcast.c:1886 add_grec+0x1380/0x1920 net/ipv6/mcast.c:2025 mld_send_cr net/ipv6/mcast.c:2148 [inline] mld_ifc_work+0x3c5/0xc10 net/ipv6/mcast.c:2693 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 page last free pid 11314 tgid 11314 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_lru_noprof+0x246/0x6e0 mm/slub.c:4885 __d_alloc+0x34/0xa80 fs/dcache.c:1740 d_alloc+0x4a/0x1e0 fs/dcache.c:1819 lookup_one_qstr_excl+0x175/0x250 fs/namei.c:1801 __start_dirop fs/namei.c:2925 [inline] start_dirop+0x59/0xb0 fs/namei.c:2934 simple_start_creating+0xf9/0x110 fs/libfs.c:2314 debugfs_start_creating.part.0+0x82/0x170 fs/debugfs/inode.c:394 debugfs_start_creating fs/debugfs/inode.c:371 [inline] debugfs_create_dir+0x72/0x440 fs/debugfs/inode.c:572 ieee80211_debugfs_add_netdev net/mac80211/debugfs_netdev.c:1004 [inline] ieee80211_debugfs_recreate_netdev+0x1d1/0x1790 net/mac80211/debugfs_netdev.c:1034 ieee80211_if_add+0xa30/0x1860 net/mac80211/iface.c:2323 ieee80211_register_hw+0x38a4/0x4140 net/mac80211/main.c:1617 mac80211_hwsim_new_radio+0x2847/0x57d0 drivers/net/wireless/virtual/mac80211_hwsim.c:5809 Memory state around the buggy address: ffff88802bde2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802bde2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802bde2480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802bde2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802bde2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================