================================================================== BUG: KASAN: use-after-free in hci_chan_del+0x36/0x1a0 net/bluetooth/hci_conn.c:2780 Read of size 8 at addr ffff88807c99eb18 by task krfcommd/3346 CPU: 1 PID: 3346 Comm: krfcommd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 hci_chan_del+0x36/0x1a0 net/bluetooth/hci_conn.c:2780 l2cap_conn_free net/bluetooth/l2cap_core.c:1868 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put net/bluetooth/l2cap_core.c:1882 [inline] l2cap_chan_destroy net/bluetooth/l2cap_core.c:502 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_chan_put+0x1f5/0x300 net/bluetooth/l2cap_core.c:529 l2cap_sock_release+0x179/0x1e0 net/bluetooth/l2cap_sock.c:1494 __sock_release net/socket.c:654 [inline] sock_release+0x7b/0x140 net/socket.c:682 rfcomm_session_del+0x141/0x200 net/bluetooth/rfcomm/core.c:781 rfcomm_process_sessions net/bluetooth/rfcomm/core.c:-1 [inline] rfcomm_run+0x46e1/0x5f10 net/bluetooth/rfcomm/core.c:2254 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 14318: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] hci_chan_create+0xc5/0x300 net/bluetooth/hci_conn.c:2765 l2cap_conn_add+0x5d/0x910 net/bluetooth/l2cap_core.c:7211 l2cap_chan_connect+0x67b/0xeb0 net/bluetooth/l2cap_core.c:7408 l2cap_sock_connect+0x576/0x750 net/bluetooth/l2cap_sock.c:259 kernel_connect+0x13e/0x1c0 net/socket.c:3555 rfcomm_session_connect net/bluetooth/rfcomm/core.c:863 [inline] rfcomm_dlc_open+0x648/0xb40 net/bluetooth/rfcomm/core.c:447 rfcomm_sock_connect+0x2e9/0x600 net/bluetooth/rfcomm/sock.c:422 __sys_connect_file net/socket.c:2011 [inline] __sys_connect+0x3cb/0x450 net/socket.c:2028 __do_sys_connect net/socket.c:2038 [inline] __se_sys_connect net/socket.c:2035 [inline] __x64_sys_connect+0x76/0x80 net/socket.c:2035 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 13616: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1735 [inline] slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1761 slab_free mm/slub.c:3694 [inline] __kmem_cache_free+0xb6/0x200 mm/slub.c:3707 hci_chan_list_flush net/bluetooth/hci_conn.c:2805 [inline] hci_conn_cleanup+0x171/0x750 net/bluetooth/hci_conn.c:149 hci_conn_del+0x4df/0x6e0 net/bluetooth/hci_conn.c:1234 hci_conn_hash_flush+0x203/0x290 net/bluetooth/hci_conn.c:2610 hci_dev_close_sync+0x989/0x10a0 net/bluetooth/hci_sync.c:5328 hci_dev_do_close net/bluetooth/hci_core.c:523 [inline] hci_unregister_dev+0x216/0x520 net/bluetooth/hci_core.c:2720 vhci_release+0x7f/0xd0 drivers/bluetooth/hci_vhci.c:565 __fput+0x20a/0x8b0 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x9d5/0x2570 kernel/exit.c:887 do_group_exit+0x229/0x2e0 kernel/exit.c:1030 __do_sys_exit_group kernel/exit.c:1041 [inline] __se_sys_exit_group kernel/exit.c:1039 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1039 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 kvfree_call_rcu+0x103/0x890 kernel/rcu/tree.c:3405 __hw_addr_flush net/core/dev_addr_lists.c:490 [inline] dev_addr_flush+0x16d/0x210 net/core/dev_addr_lists.c:535 free_netdev+0x1ea/0x4c0 net/core/dev.c:10916 netdev_run_todo+0xc19/0xdb0 net/core/dev.c:10577 default_device_exit_batch+0x963/0x9f0 net/core/dev.c:11574 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x78e/0xba0 net/core/net_namespace.c:640 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 kvfree_call_rcu+0x103/0x890 kernel/rcu/tree.c:3405 __hw_addr_del_entry net/core/dev_addr_lists.c:161 [inline] __hw_addr_del_ex+0x3fb/0x4e0 net/core/dev_addr_lists.c:200 __dev_mc_del net/core/dev_addr_lists.c:908 [inline] dev_mc_del+0x99/0x110 net/core/dev_addr_lists.c:926 ip_mc_filter_del net/ipv4/igmp.c:1182 [inline] __igmp_group_dropped+0x1e5/0x8e0 net/ipv4/igmp.c:1315 igmp_group_dropped net/ipv4/igmp.c:1346 [inline] ip_mc_down+0xf2/0x340 net/ipv4/igmp.c:1755 inetdev_event+0x332/0x13f0 net/ipv4/devinet.c:1601 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] dev_close_many+0x2a2/0x400 net/core/dev.c:1614 unregister_netdevice_many_notify+0x497/0x1990 net/core/dev.c:11021 unregister_netdevice_many net/core/dev.c:11101 [inline] default_device_exit_batch+0x95e/0x9f0 net/core/dev.c:11573 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x78e/0xba0 net/core/net_namespace.c:640 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff88807c99eb00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 24 bytes inside of 128-byte region [ffff88807c99eb00, ffff88807c99eb80) The buggy address belongs to the physical page: page:ffffea0001f26780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c99e flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 dead000000000100 dead000000000122 ffff8880184418c0 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 3937, tgid 3937 (dhcpcd), ts 46927498151, free_ts 44776261019 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_slab_page+0x5d/0x180 mm/slub.c:1805 allocate_slab mm/slub.c:1950 [inline] new_slab+0x87/0x2d0 mm/slub.c:2003 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3161 __slab_alloc mm/slub.c:3247 [inline] slab_alloc_node mm/slub.c:3332 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3405 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa3/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] tomoyo_commit_ok+0x25/0x1c0 security/tomoyo/memory.c:76 tomoyo_update_domain+0x4df/0x7c0 security/tomoyo/domain.c:139 tomoyo_write_inet_network+0x3ee/0x4c0 security/tomoyo/network.c:311 tomoyo_write_domain2 security/tomoyo/common.c:1143 [inline] tomoyo_add_entry security/tomoyo/common.c:2033 [inline] tomoyo_supervisor+0xe74/0x11b0 security/tomoyo/common.c:2094 tomoyo_audit_net_log security/tomoyo/network.c:367 [inline] tomoyo_audit_inet_log security/tomoyo/network.c:393 [inline] tomoyo_inet_entry security/tomoyo/network.c:484 [inline] tomoyo_check_inet_address+0x5ce/0x8f0 security/tomoyo/network.c:532 tomoyo_socket_bind_permission+0x1c6/0x270 security/tomoyo/network.c:745 security_socket_bind+0x6c/0xa0 security/security.c:2259 __sys_bind+0x289/0x3e0 net/socket.c:1807 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1487 [inline] free_pcp_prepare mm/page_alloc.c:1537 [inline] free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x490 mm/slab.h:742 slab_alloc_node mm/slub.c:3366 [inline] __kmem_cache_alloc_node+0x19d/0x270 mm/slub.c:3405 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] kernfs_fop_open+0x3ce/0xc60 fs/kernfs/file.c:690 do_dentry_open+0x7dd/0x10b0 fs/open.c:882 do_open fs/namei.c:3677 [inline] path_openat+0x2674/0x2f10 fs/namei.c:3838 do_filp_open+0x1ee/0x420 fs/namei.c:3865 do_sys_openat2+0x14b/0x4f0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff88807c99ea00: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ffff88807c99ea80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807c99eb00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c99eb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807c99ec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ==================================================================