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BUG: KASAN: use-after-free in constant_test_bit arch/x86/include/asm/bitops.h:317 [inline]
BUG: KASAN: use-after-free in sock_flag include/net/sock.h:839 [inline]
BUG: KASAN: use-after-free in l2cap_sock_kill net/bluetooth/l2cap_sock.c:1046 [inline]
BUG: KASAN: use-after-free in l2cap_sock_close_cb+0xbd/0xd0 net/bluetooth/l2cap_sock.c:1311
Read of size 8 at addr ffff88804affa0e0 by task kworker/1:2/21534

CPU: 1 PID: 21534 Comm: kworker/1:2 Not tainted 4.19.143-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
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
 constant_test_bit arch/x86/include/asm/bitops.h:317 [inline]
 sock_flag include/net/sock.h:839 [inline]
 l2cap_sock_kill net/bluetooth/l2cap_sock.c:1046 [inline]
 l2cap_sock_close_cb+0xbd/0xd0 net/bluetooth/l2cap_sock.c:1311
 l2cap_chan_timeout+0x1bb/0x210 net/bluetooth/l2cap_core.c:431
 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

Allocated by task 30900:
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc+0x15a/0x3c0 mm/slab.c:3736
 kmalloc include/linux/slab.h:520 [inline]
 sk_prot_alloc+0x1e2/0x2d0 net/core/sock.c:1466
 sk_alloc+0x36/0xec0 net/core/sock.c:1520
 l2cap_sock_alloc.constprop.0+0x31/0x210 net/bluetooth/l2cap_sock.c:1590
 l2cap_sock_create+0x110/0x1b0 net/bluetooth/l2cap_sock.c:1636
 bt_sock_create+0x154/0x2a0 net/bluetooth/af_bluetooth.c:130
 __sock_create+0x3d8/0x740 net/socket.c:1276
 rfcomm_l2sock_create net/bluetooth/rfcomm/core.c:203 [inline]
 rfcomm_session_create net/bluetooth/rfcomm/core.c:738 [inline]
 __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline]
 rfcomm_dlc_open+0x6e2/0xcb0 net/bluetooth/rfcomm/core.c:431
 rfcomm_sock_connect+0x317/0x420 net/bluetooth/rfcomm/sock.c:416
 __sys_connect+0x265/0x2c0 net/socket.c:1663
 __do_sys_connect net/socket.c:1674 [inline]
 __se_sys_connect net/socket.c:1671 [inline]
 __x64_sys_connect+0x6f/0xb0 net/socket.c:1671
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3596:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 sk_prot_free net/core/sock.c:1503 [inline]
 __sk_destruct+0x5ff/0x810 net/core/sock.c:1584
 sk_destruct net/core/sock.c:1599 [inline]
 __sk_free+0x165/0x3b0 net/core/sock.c:1610
 sk_free+0x3b/0x50 net/core/sock.c:1621
 sock_put include/net/sock.h:1711 [inline]
 l2cap_sock_kill.part.0+0x6b/0x80 net/bluetooth/l2cap_sock.c:1055
 l2cap_sock_kill net/bluetooth/l2cap_sock.c:1206 [inline]
 l2cap_sock_release+0x158/0x190 net/bluetooth/l2cap_sock.c:1204
 __sock_release net/socket.c:579 [inline]
 sock_release+0x87/0x1d0 net/socket.c:599
 rfcomm_session_del+0x15a/0x1f0 net/bluetooth/rfcomm/core.c:684
 rfcomm_session_close net/bluetooth/rfcomm/core.c:723 [inline]
 rfcomm_process_rx net/bluetooth/rfcomm/core.c:1916 [inline]
 rfcomm_process_sessions net/bluetooth/rfcomm/core.c:2000 [inline]
 rfcomm_run+0x12ed/0x4250 net/bluetooth/rfcomm/core.c:2087
 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 ffff88804affa080
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 96 bytes inside of
 2048-byte region [ffff88804affa080, ffff88804affa880)
The buggy address belongs to the page:
netlink: 16 bytes leftover after parsing attributes in process `syz-executor.3'.
page:ffffea00012bfe80 count:1 mapcount:0 mapping:ffff88812c39cc40 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea0000febd88 ffffea00012e4a08 ffff88812c39cc40
raw: 0000000000000000 ffff88804affa080 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804aff9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88804affa000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804affa080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88804affa100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804affa180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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