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BUG: KASAN: use-after-free in hci_chan_del+0x1b4/0x1f0 net/bluetooth/hci_conn.c:1683
Read of size 8 at addr ffff88809e2eca98 by task syz-executor.5/19205

CPU: 0 PID: 19205 Comm: syz-executor.5 Not tainted 4.19.161-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 hci_chan_del+0x1b4/0x1f0 net/bluetooth/hci_conn.c:1683
 l2cap_conn_del+0x45e/0x6e0 net/bluetooth/l2cap_core.c:1739
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7441 [inline]
 l2cap_disconn_cfm+0x98/0xd0 net/bluetooth/l2cap_core.c:7434
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1261 [inline]
 hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1512
 hci_dev_do_close+0x659/0xf10 net/bluetooth/hci_core.c:1666
 hci_rfkill_set_block+0xe7/0x160 net/bluetooth/hci_core.c:2100
 rfkill_set_block+0x1f9/0x540 net/rfkill/core.c:353
 rfkill_fop_write+0x250/0x4a0 net/rfkill/core.c:1249
 __vfs_write+0xf7/0x770 fs/read_write.c:485
 vfs_write+0x1f3/0x540 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45de79
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc8f0764c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045de79
RDX: 0000000000000008 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffd7714ec2f R14: 00007fc8f07659c0 R15: 000000000118bf2c

Allocated by task 7:
 kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 addr_event.part.0+0x7b/0x460 drivers/infiniband/core/roce_gid_mgmt.c:835
 addr_event drivers/infiniband/core/roce_gid_mgmt.c:819 [inline]
 inetaddr_event+0x135/0x1a0 drivers/infiniband/core/roce_gid_mgmt.c:864
 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
 __blocking_notifier_call_chain kernel/notifier.c:317 [inline]
 __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 blocking_notifier_call_chain+0x85/0xa0 kernel/notifier.c:325
 __inet_del_ifa+0x534/0xba0 net/ipv4/devinet.c:416
 inet_del_ifa net/ipv4/devinet.c:446 [inline]
 inetdev_destroy net/ipv4/devinet.c:311 [inline]
 inetdev_event+0x5cb/0x1263 net/ipv4/devinet.c:1545
 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
 call_netdevice_notifiers net/core/dev.c:1762 [inline]
 rollback_registered_many+0x83e/0xe70 net/core/dev.c:8188
 unregister_netdevice_many.part.0+0x1a/0x300 net/core/dev.c:9311
 unregister_netdevice_many net/core/dev.c:9310 [inline]
 default_device_exit_batch+0x2fa/0x3c0 net/core/dev.c:9782
 ops_exit_list+0xf9/0x150 net/core/net_namespace.c:156
 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:553
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Freed by task 9611:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

The buggy address belongs to the object at ffff88809e2eca80
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
 128-byte region [ffff88809e2eca80, ffff88809e2ecb00)
The buggy address belongs to the page:
page:ffffea000278bb00 count:1 mapcount:0 mapping:ffff88813bff0640 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002adbac8 ffffea00026cc888 ffff88813bff0640
raw: 0000000000000000 ffff88809e2ec000 0000000100000015 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809e2ec980: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff88809e2eca00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>ffff88809e2eca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88809e2ecb00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff88809e2ecb80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
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