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BUG: KASAN: use-after-free in atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
BUG: KASAN: use-after-free in hci_sock_bind+0x521/0x1000 net/bluetooth/hci_sock.c:1226
Write of size 4 at addr ffff88804aa22260 by task syz-executor.4/30098

CPU: 0 PID: 30098 Comm: syz-executor.4 Not tainted 4.19.120-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+0x188/0x20d lib/dump_stack.c:118
 print_address_description.cold+0x7c/0x212 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396
 atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
 hci_sock_bind+0x521/0x1000 net/bluetooth/hci_sock.c:1226
 __sys_bind+0x20e/0x250 net/socket.c:1482
 __do_sys_bind net/socket.c:1493 [inline]
 __se_sys_bind net/socket.c:1491 [inline]
 __x64_sys_bind+0x6f/0xb0 net/socket.c:1491
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c829
Code: 0d b7 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fcbca4cac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 00000000004d9640 RCX: 000000000045c829
RDX: 0000000000000006 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 000000000000002c R14: 00000000004c2cd9 R15: 00007fcbca4cb6d4

Allocated by task 30098:
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531
 kmem_cache_alloc_trace+0x14d/0x7a0 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 hci_alloc_dev+0x3e/0x1cf0 net/bluetooth/hci_core.c:3053
 __vhci_create_device+0x100/0x580 drivers/bluetooth/hci_vhci.c:114
 vhci_create_device drivers/bluetooth/hci_vhci.c:163 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:219 [inline]
 vhci_write+0x2c5/0x460 drivers/bluetooth/hci_vhci.c:299
 call_write_iter include/linux/fs.h:1821 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x512/0x760 fs/read_write.c:487
 vfs_write+0x206/0x550 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

Freed by task 30094:
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xce/0x220 mm/slab.c:3822
 bt_host_release+0x15/0x20 net/bluetooth/hci_sysfs.c:86
 device_release+0x76/0x210 drivers/base/core.c:1061
 kobject_cleanup lib/kobject.c:662 [inline]
 kobject_release lib/kobject.c:691 [inline]
 kref_put include/linux/kref.h:70 [inline]
 kobject_put+0x17c/0x270 lib/kobject.c:708
 put_device+0x1c/0x30 drivers/base/core.c:2251
 vhci_release+0x78/0xe0 drivers/bluetooth/hci_vhci.c:355
 __fput+0x2cd/0x890 fs/file_table.c:278
 task_work_run+0x13f/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x25a/0x2b0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88804aa21200
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 4192 bytes inside of
 8192-byte region [ffff88804aa21200, ffff88804aa23200)
The buggy address belongs to the page:
page:ffffea00012a8800 count:1 mapcount:0 mapping:ffff88812c395080 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea0000bffc08 ffffea0000be2508 ffff88812c395080
raw: 0000000000000000 ffff88804aa21200 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804aa22100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804aa22180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88804aa22200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88804aa22280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804aa22300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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