================================================================== BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic_dec_and_test include/asm-generic/atomic-instrumented.h:748 [inline] BUG: KASAN: use-after-free in hci_conn_drop include/net/bluetooth/hci_core.h:1116 [inline] BUG: KASAN: use-after-free in sco_chan_del+0xe6/0x430 net/bluetooth/sco.c:149 Write of size 4 at addr ffff888092ba2010 by task syz-executor373/6891 CPU: 1 PID: 6891 Comm: syz-executor373 Not tainted 5.8.0-next-20200810-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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 instrument_atomic_write include/linux/instrumented.h:71 [inline] atomic_dec_and_test include/asm-generic/atomic-instrumented.h:748 [inline] hci_conn_drop include/net/bluetooth/hci_core.h:1116 [inline] sco_chan_del+0xe6/0x430 net/bluetooth/sco.c:149 __sco_sock_close+0x16e/0x5b0 net/bluetooth/sco.c:434 sco_sock_close net/bluetooth/sco.c:448 [inline] sco_sock_release+0x69/0x290 net/bluetooth/sco.c:1053 __sock_release+0xcd/0x280 net/socket.c:596 sock_close+0x18/0x20 net/socket.c:1277 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 exit_task_work include/linux/task_work.h:25 [inline] do_exit+0xb7d/0x29f0 kernel/exit.c:806 do_group_exit+0x125/0x310 kernel/exit.c:903 get_signal+0x40b/0x1ee0 kernel/signal.c:2743 arch_do_signal+0x82/0x2520 arch/x86/kernel/signal.c:811 exit_to_user_mode_loop kernel/entry/common.c:135 [inline] exit_to_user_mode_prepare+0x15d/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x446dc9 Code: Bad RIP value. RSP: 002b:00007ffdb64a82d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 0000000000446dc9 RDX: 0000000000000008 RSI: 0000000020000080 RDI: 0000000000000004 RBP: 00007ffdb64a8310 R08: 0000000000000002 R09: 00000000000000ff R10: 0000000000000004 R11: 0000000000000246 R12: 000000000000f8fb R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6886: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 kmem_cache_alloc_trace+0x16e/0x2c0 mm/slab.c:3550 kmalloc include/linux/slab.h:554 [inline] kzalloc include/linux/slab.h:666 [inline] hci_conn_add+0x53/0x1330 net/bluetooth/hci_conn.c:525 hci_connect_sco+0x356/0x860 net/bluetooth/hci_conn.c:1283 sco_connect net/bluetooth/sco.c:241 [inline] sco_sock_connect+0x308/0x980 net/bluetooth/sco.c:588 __sys_connect_file+0x155/0x1a0 net/socket.c:1852 __sys_connect+0x161/0x190 net/socket.c:1869 __do_sys_connect net/socket.c:1879 [inline] __se_sys_connect net/socket.c:1876 [inline] __x64_sys_connect+0x6f/0xb0 net/socket.c:1876 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 6884: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kfree+0x103/0x2c0 mm/slab.c:3756 device_release+0x71/0x200 drivers/base/core.c:1800 kobject_cleanup lib/kobject.c:704 [inline] kobject_release lib/kobject.c:735 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x171/0x270 lib/kobject.c:752 put_device+0x1b/0x30 drivers/base/core.c:3029 hci_conn_del+0x27e/0x6a0 net/bluetooth/hci_conn.c:645 hci_phy_link_complete_evt.isra.0+0x508/0x790 net/bluetooth/hci_event.c:4940 hci_event_packet+0x4696/0x87a8 net/bluetooth/hci_event.c:6205 hci_rx_work+0x22e/0xb50 net/bluetooth/hci_core.c:4889 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 The buggy address belongs to the object at ffff888092ba2000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 16 bytes inside of 4096-byte region [ffff888092ba2000, ffff888092ba3000) The buggy address belongs to the page: page:00000000450b3bde refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x92ba2 head:00000000450b3bde order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00024d5988 ffffea0002491b88 ffff8880aa040900 raw: 0000000000000000 ffff888092ba2000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888092ba1f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888092ba1f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888092ba2000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888092ba2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888092ba2100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================