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BUG: KASAN: use-after-free in rfcomm_dlc_get net/bluetooth/rfcomm/core.c:360 [inline]
BUG: KASAN: use-after-free in __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:396 [inline]
BUG: KASAN: use-after-free in rfcomm_dlc_open+0xc9d/0xd80 net/bluetooth/rfcomm/core.c:431
Read of size 1 at addr ffff888092e5c904 by task syz-executor.3/4087

CPU: 0 PID: 4087 Comm: syz-executor.3 Not tainted 5.2.0+ #67
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351
 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482
 kasan_report+0x12/0x17 mm/kasan/common.c:612
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:129
 rfcomm_dlc_get net/bluetooth/rfcomm/core.c:360 [inline]
 __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:396 [inline]
 rfcomm_dlc_open+0xc9d/0xd80 net/bluetooth/rfcomm/core.c:431
 rfcomm_sock_connect+0x38a/0x4b0 net/bluetooth/rfcomm/sock.c:416
 __sys_connect+0x264/0x330 net/socket.c:1828
 __do_sys_connect net/socket.c:1839 [inline]
 __se_sys_connect net/socket.c:1836 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1836
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: fd 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fbdf9321c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829
RDX: 000000000000000e RSI: 0000000020000080 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbdf93226d4
R13: 00000000004bfd0a R14: 00000000004d19d0 R15: 00000000ffffffff

Allocated by task 3967:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:487 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:460
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:501
 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3550
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:748 [inline]
 __do_execve_file.isra.0+0x325/0x2340 fs/exec.c:1749
 do_execveat_common fs/exec.c:1868 [inline]
 do_execve fs/exec.c:1885 [inline]
 __do_sys_execve fs/exec.c:1961 [inline]
 __se_sys_execve fs/exec.c:1956 [inline]
 __x64_sys_execve+0x8f/0xc0 fs/exec.c:1956
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3967:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:449
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:457
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3756
 free_bprm+0x198/0x200 fs/exec.c:1433
 __do_execve_file.isra.0+0x1b3f/0x2340 fs/exec.c:1832
 do_execveat_common fs/exec.c:1868 [inline]
 do_execve fs/exec.c:1885 [inline]
 __do_sys_execve fs/exec.c:1961 [inline]
 __se_sys_execve fs/exec.c:1956 [inline]
 __x64_sys_execve+0x8f/0xc0 fs/exec.c:1956
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888092e5c7c0
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 324 bytes inside of
 512-byte region [ffff888092e5c7c0, ffff888092e5c9c0)
The buggy address belongs to the page:
page:ffffea00024b9700 refcount:1 mapcount:0 mapping:ffff8880aa400a80 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00028ec148 ffffea00022c7f88 ffff8880aa400a80
raw: 0000000000000000 ffff888092e5c040 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888092e5c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888092e5c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888092e5c900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888092e5c980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888092e5ca00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
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