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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_exists+0x17d/0x1a0 net/bluetooth/rfcomm/core.c:550
Read of size 1 at addr ffff88801ec52144 by task syz-executor.2/4139

CPU: 1 PID: 4139 Comm: syz-executor.2 Not tainted 5.5.0-rc6-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 rfcomm_dlc_get net/bluetooth/rfcomm/core.c:360 [inline]
 rfcomm_dlc_exists+0x17d/0x1a0 net/bluetooth/rfcomm/core.c:550
 __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:413 [inline]
 rfcomm_create_dev net/bluetooth/rfcomm/tty.c:486 [inline]
 rfcomm_dev_ioctl+0x9ff/0x1e80 net/bluetooth/rfcomm/tty.c:588
 rfcomm_sock_ioctl+0x90/0xb0 net/bluetooth/rfcomm/sock.c:902
 rfcomm_sock_compat_ioctl+0x24/0x30 net/bluetooth/rfcomm/sock.c:915
 compat_sock_ioctl+0x169/0x2240 net/socket.c:3568
 __do_compat_sys_ioctl fs/compat_ioctl.c:214 [inline]
 __se_compat_sys_ioctl fs/compat_ioctl.c:142 [inline]
 __ia32_compat_sys_ioctl+0x233/0x610 fs/compat_ioctl.c:142
 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
 do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f2ea39
Code: 00 00 00 89 d3 5b 5e 5f 5d c3 b8 80 96 98 00 eb c4 8b 04 24 c3 8b 1c 24 c3 8b 34 24 c3 8b 3c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5d2a0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000400452c8
RDX: 0000000020000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 19501:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527
 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3551
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:670 [inline]
 rfcomm_dlc_alloc+0x82/0x410 net/bluetooth/rfcomm/core.c:305
 rfcomm_sock_alloc.constprop.0+0xb3/0x370 net/bluetooth/rfcomm/sock.c:286
 rfcomm_sock_create+0xf3/0x2b0 net/bluetooth/rfcomm/sock.c:329
 bt_sock_create+0x16a/0x2d0 net/bluetooth/af_bluetooth.c:130
 __sock_create+0x3ce/0x730 net/socket.c:1420
 sock_create net/socket.c:1471 [inline]
 __sys_socket+0x103/0x220 net/socket.c:1513
 __do_sys_socket net/socket.c:1522 [inline]
 __se_sys_socket net/socket.c:1520 [inline]
 __ia32_sys_socket+0x73/0xb0 net/socket.c:1520
 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
 do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 4134:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:335 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3757
 rfcomm_dlc_free+0x20/0x30 net/bluetooth/rfcomm/core.c:328
 rfcomm_dlc_put include/net/bluetooth/rfcomm.h:258 [inline]
 __rfcomm_create_dev net/bluetooth/rfcomm/tty.c:417 [inline]
 rfcomm_create_dev net/bluetooth/rfcomm/tty.c:486 [inline]
 rfcomm_dev_ioctl+0x1b9d/0x1e80 net/bluetooth/rfcomm/tty.c:588
 rfcomm_sock_ioctl+0x90/0xb0 net/bluetooth/rfcomm/sock.c:902
 rfcomm_sock_compat_ioctl+0x24/0x30 net/bluetooth/rfcomm/sock.c:915
 compat_sock_ioctl+0x169/0x2240 net/socket.c:3568
 __do_compat_sys_ioctl fs/compat_ioctl.c:214 [inline]
 __se_compat_sys_ioctl fs/compat_ioctl.c:142 [inline]
 __ia32_compat_sys_ioctl+0x233/0x610 fs/compat_ioctl.c:142
 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
 do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff88801ec52000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 324 bytes inside of
 512-byte region [ffff88801ec52000, ffff88801ec52200)
The buggy address belongs to the page:
page:ffffea00007b1480 refcount:1 mapcount:0 mapping:ffff88802cc00a80 index:0xffff88801ec52800
raw: 00fffe0000000200 ffffea00008d3588 ffffea000072c308 ffff88802cc00a80
raw: ffff88801ec52800 ffff88801ec52000 0000000100000002 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88801ec52000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801ec52080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801ec52100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88801ec52180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801ec52200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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