kobject: kobject_add_internal failed for hci2:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci2: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0xe75/0x1010 net/bluetooth/l2cap_core.c:7305 Read of size 8 at addr ffff888043de9480 by task kworker/u9:4/5836 CPU: 1 UID: 0 PID: 5836 Comm: kworker/u9:4 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: hci2 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/0x1a0 mm/kasan/report.c:595 l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline] l2cap_connect_cfm+0xe75/0x1010 net/bluetooth/l2cap_core.c:7305 hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline] le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7773 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4076 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 5836: 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:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2cap_chan_create+0x44/0x940 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc.constprop.0+0xf5/0x1e0 net/bluetooth/l2cap_sock.c:1906 l2cap_sock_new_connection_cb+0x101/0x260 net/bluetooth/l2cap_sock.c:1485 l2cap_connect_cfm+0x4e2/0x1010 net/bluetooth/l2cap_core.c:7288 hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline] le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7773 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4076 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Freed by task 21991: 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:2540 [inline] slab_free mm/slub.c:6674 [inline] kfree+0x1c7/0x690 mm/slub.c:6882 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:1468 l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1426 __sock_release+0xb3/0x260 net/socket.c:662 sock_close+0x1c/0x30 net/socket.c:1455 __fput+0x3ff/0xb40 fs/file_table.c:468 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:44 [inline] exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75 __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_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888043de9000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1152 bytes inside of freed 2048-byte region [ffff888043de9000, ffff888043de9800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43de8 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 ffff88813ff27000 ffffea0001f57a00 dead000000000002 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ff27000 ffffea0001f57a00 dead000000000002 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00010f7a01 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 2983, tgid 2983 (kworker/u8:8), ts 1130916274711, free_ts 1130762023608 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0xe3d/0x2e10 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5240 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c4/0x440 mm/slub.c:3302 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_node_track_caller_noprof+0x629/0x9d0 mm/slub.c:5768 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:608 __alloc_skb+0x186/0x410 net/core/skbuff.c:690 alloc_skb include/linux/skbuff.h:1383 [inline] nlmsg_new include/net/netlink.h:1055 [inline] rtmsg_ifinfo_build_skb+0x81/0x260 net/core/rtnetlink.c:4407 unregister_netdevice_many_notify+0x12b6/0x2580 net/core/dev.c:12399 ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] ops_undo_list+0x8ff/0xab0 net/core/net_namespace.c:248 cleanup_net+0x419/0x830 net/core/net_namespace.c:696 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 page last free pid 2983 tgid 2983 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x822/0x1130 mm/page_alloc.c:2973 discard_slab mm/slub.c:3346 [inline] __put_partials+0x127/0x160 mm/slub.c:3886 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:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x303/0x880 mm/slub.c:5315 __alloc_skb+0x156/0x410 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] nlmsg_new include/net/netlink.h:1055 [inline] inet_ifmcaddr_notify+0xc7/0x1b0 net/ipv4/igmp.c:1481 __ip_mc_dec_group+0x41d/0x590 net/ipv4/igmp.c:1778 inetdev_event+0x142/0x17f0 net/ipv4/devinet.c:1641 notifier_call_chain+0x99/0x3b0 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2243 call_netdevice_notifiers_extack net/core/dev.c:2281 [inline] call_netdevice_notifiers net/core/dev.c:2295 [inline] netif_close_many+0x319/0x630 net/core/dev.c:1798 netif_close net/core/dev.c:1811 [inline] netif_close+0x17f/0x230 net/core/dev.c:1805 dev_close+0xaa/0x240 net/core/dev_api.c:220 __bond_release_one.cold+0x62f/0x1064 drivers/net/bonding/bond_main.c:2478 Memory state around the buggy address: ffff888043de9380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888043de9400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888043de9480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888043de9500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888043de9580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ================================================================== BUG: KASAN: wild-memory-access in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: wild-memory-access in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: wild-memory-access in l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] BUG: KASAN: wild-memory-access in l2cap_conn_ready net/bluetooth/l2cap_core.c:1626 [inline] BUG: KASAN: wild-memory-access in l2cap_connect_cfm+0x7c0/0x1010 net/bluetooth/l2cap_core.c:7305 Read of size 4 at addr deacfffffffffc8c by task kworker/u9:4/5836 CPU: 1 UID: 0 PID: 5836 Comm: kworker/u9:4 Tainted: G B L syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: hci2 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] l2cap_conn_ready net/bluetooth/l2cap_core.c:1626 [inline] l2cap_connect_cfm+0x7c0/0x1010 net/bluetooth/l2cap_core.c:7305 hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline] le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7773 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4076 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 ================================================================== Oops: general protection fault, probably for non-canonical address 0xfbd59bffffffff91: 0000 [#1] SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0xdeacfffffffffc88-0xdeacfffffffffc8f] CPU: 1 UID: 0 PID: 5836 Comm: kworker/u9:4 Tainted: G B L syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: hci2 hci_rx_work RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] RIP: 0010:l2cap_conn_ready net/bluetooth/l2cap_core.c:1626 [inline] RIP: 0010:l2cap_connect_cfm+0x7c7/0x1010 net/bluetooth/l2cap_core.c:7305 Code: 80 fb ff ff 49 39 c7 0f 84 29 01 00 00 e8 21 f1 8b f7 49 8d 6e 0c be 04 00 00 00 48 89 ef e8 e0 53 f5 f7 48 89 e8 48 c1 e8 03 <0f> b6 14 18 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 83 RSP: 0018:ffffc9000406f7d0 EFLAGS: 00010213 RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001e414000 RDX: 0000000000000000 RSI: ffffffff81c58c8d RDI: ffff8880353a9e80 RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 695f756372203f20 R12: ffff88805873003d R13: 0000000000000080 R14: deacfffffffffc80 R15: ffff8880342b1ac0 FS: 0000000000000000(0000) GS:ffff8881246dc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f999ebe8600 CR3: 0000000069f9f000 CR4: 0000000000350ef0 Call Trace: hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline] le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5821 hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847 hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7408 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7773 hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4076 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline] RIP: 0010:l2cap_conn_ready net/bluetooth/l2cap_core.c:1626 [inline] RIP: 0010:l2cap_connect_cfm+0x7c7/0x1010 net/bluetooth/l2cap_core.c:7305 Code: 80 fb ff ff 49 39 c7 0f 84 29 01 00 00 e8 21 f1 8b f7 49 8d 6e 0c be 04 00 00 00 48 89 ef e8 e0 53 f5 f7 48 89 e8 48 c1 e8 03 <0f> b6 14 18 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 83 RSP: 0018:ffffc9000406f7d0 EFLAGS: 00010213 RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001e414000 RDX: 0000000000000000 RSI: ffffffff81c58c8d RDI: ffff8880353a9e80 RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 695f756372203f20 R12: ffff88805873003d R13: 0000000000000080 R14: deacfffffffffc80 R15: ffff8880342b1ac0 FS: 0000000000000000(0000) GS:ffff8881246dc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f999ebe8600 CR3: 000000000e392000 CR4: 0000000000350ef0 ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 49 39 c7 cmp %rax,%r15 3: 0f 84 29 01 00 00 je 0x132 9: e8 21 f1 8b f7 call 0xf78bf12f e: 49 8d 6e 0c lea 0xc(%r14),%rbp 12: be 04 00 00 00 mov $0x4,%esi 17: 48 89 ef mov %rbp,%rdi 1a: e8 e0 53 f5 f7 call 0xf7f553ff 1f: 48 89 e8 mov %rbp,%rax 22: 48 c1 e8 03 shr $0x3,%rax * 26: 0f b6 14 18 movzbl (%rax,%rbx,1),%edx <-- trapping instruction 2a: 48 89 e8 mov %rbp,%rax 2d: 83 e0 07 and $0x7,%eax 30: 83 c0 03 add $0x3,%eax 33: 38 d0 cmp %dl,%al 35: 7c 08 jl 0x3f 37: 84 d2 test %dl,%dl 39: 0f .byte 0xf 3a: 85 .byte 0x85 3b: 83 .byte 0x83