================================================================== BUG: KASAN: use-after-free in hci_chan_del+0x36/0x1a0 net/bluetooth/hci_conn.c:2780 Read of size 8 at addr ffff888027775e18 by task kworker/0:12/5948 CPU: 0 PID: 5948 Comm: kworker/0:12 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Workqueue: events delayed_fput 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_close+0xbf/0x210 net/socket.c:1400 __fput+0x20a/0x8b0 fs/file_table.c:320 delayed_fput+0x54/0x80 fs/file_table.c:343 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 Allocated by task 4286: 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_connect_cfm+0x131/0x1230 net/bluetooth/l2cap_core.c:7598 hci_connect_cfm include/net/bluetooth/hci_core.h:1822 [inline] hci_remote_features_evt+0x4cc/0xa10 net/bluetooth/hci_event.c:3756 hci_event_func net/bluetooth/hci_event.c:7304 [inline] hci_event_packet+0x66a/0xe60 net/bluetooth/hci_event.c:7353 hci_rx_work+0x3eb/0xd40 net/bluetooth/hci_core.c:4041 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 Freed by task 4517: 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 call_rcu+0x14f/0x950 kernel/rcu/tree.c:2849 tnode_free net/ipv4/fib_trie.c:496 [inline] replace+0x237/0x5c0 net/ipv4/fib_trie.c:522 inflate net/ipv4/fib_trie.c:624 [inline] resize+0xfd4/0x2620 net/ipv4/fib_trie.c:869 trie_rebalance net/ipv4/fib_trie.c:1104 [inline] fib_insert_node net/ipv4/fib_trie.c:1148 [inline] fib_insert_alias+0xea0/0x1280 net/ipv4/fib_trie.c:1162 fib_table_insert+0x66e/0x1af0 net/ipv4/fib_trie.c:1357 fib_magic+0x2ca/0x3b0 net/ipv4/fib_frontend.c:1118 fib_add_ifaddr+0x135/0x5c0 net/ipv4/fib_frontend.c:1140 fib_inetaddr_event+0x13c/0x1c0 net/ipv4/fib_frontend.c:1454 notifier_call_chain kernel/notifier.c:87 [inline] blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:382 __inet_insert_ifa+0x9c4/0xb80 net/ipv4/devinet.c:568 inet_rtm_newaddr+0xb90/0x1950 net/ipv4/devinet.c:970 rtnetlink_rcv_msg+0x863/0xfb0 net/core/rtnetlink.c:6166 netlink_rcv_skb+0x1ef/0x440 net/netlink/af_netlink.c:2516 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x7ad/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1877 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x497/0x650 net/socket.c:2153 __do_sys_sendto net/socket.c:2165 [inline] __se_sys_sendto net/socket.c:2161 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2161 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 The buggy address belongs to the object at ffff888027775e00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 24 bytes inside of 128-byte region [ffff888027775e00, ffff888027775e80) The buggy address belongs to the physical page: page:ffffea00009ddd40 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888027775300 pfn:0x27775 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001dc3c88 ffffea00015ea008 ffff8880184418c0 raw: ffff888027775300 000000000010000a 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 0x12a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 7, tgid 7 (kworker/0:0), ts 86394744850, free_ts 86337767131 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 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] __hw_addr_create net/core/dev_addr_lists.c:60 [inline] __hw_addr_add_ex+0x1f4/0x700 net/core/dev_addr_lists.c:118 __dev_mc_add net/core/dev_addr_lists.c:867 [inline] dev_mc_add+0x9d/0x110 net/core/dev_addr_lists.c:885 igmp6_group_added+0x218/0x5f0 net/ipv6/mcast.c:684 __ipv6_dev_mc_inc+0x959/0xb20 net/ipv6/mcast.c:955 addrconf_join_solict net/ipv6/addrconf.c:2205 [inline] addrconf_dad_begin net/ipv6/addrconf.c:4054 [inline] addrconf_dad_work+0x3b8/0x1500 net/ipv6/addrconf.c:4179 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 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_list+0xbb/0x8e0 mm/page_alloc.c:3555 release_pages+0x20d1/0x2340 mm/swap.c:1035 tlb_batch_pages_flush mm/mmu_gather.c:60 [inline] tlb_flush_mmu_free mm/mmu_gather.c:255 [inline] tlb_flush_mmu+0x105/0x220 mm/mmu_gather.c:262 tlb_finish_mmu+0xf0/0x220 mm/mmu_gather.c:394 exit_mmap+0x388/0x970 mm/mmap.c:3305 __mmput+0x118/0x3a0 kernel/fork.c:1214 exit_mm+0x24d/0x350 kernel/exit.c:572 do_exit+0x958/0x2570 kernel/exit.c:874 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 Memory state around the buggy address: ffff888027775d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ffff888027775d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888027775e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888027775e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888027775f00: 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