================================================================== 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 ffff88809e9182a0 by task syz-executor979/26954 CPU: 0 PID: 26954 Comm: syz-executor979 Not tainted 4.19.136-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+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_conn_del+0x3db/0x6b0 net/bluetooth/l2cap_core.c:1730 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7435 [inline] l2cap_disconn_cfm+0x85/0xa0 net/bluetooth/l2cap_core.c:7428 hci_disconn_cfm include/net/bluetooth/hci_core.h:1261 [inline] hci_conn_hash_flush+0x114/0x220 net/bluetooth/hci_conn.c:1495 hci_dev_do_close+0x624/0xe70 net/bluetooth/hci_core.c:1666 hci_unregister_dev+0x17c/0x7f0 net/bluetooth/hci_core.c:3271 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:354 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbb2/0x2b70 kernel/exit.c:887 do_group_exit+0x125/0x310 kernel/exit.c:990 get_signal+0x3f2/0x1f70 kernel/signal.c:2588 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:821 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 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 RIP: 0033:0x447169 Code: e8 4c e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 3b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa8bff16db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00000000006dcc28 RCX: 0000000000447169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dcc28 RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc2c R13: 00007ffd57ed7e7f R14: 00007fa8bff179c0 R15: 0000000000000064 Allocated by task 21624: __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 sock_create net/socket.c:1316 [inline] __sys_socket+0xef/0x200 net/socket.c:1346 __do_sys_socket net/socket.c:1355 [inline] __se_sys_socket net/socket.c:1353 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1353 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 21626: __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:1707 [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+0xcd/0x2a0 net/socket.c:579 sock_close+0x15/0x20 net/socket.c:1140 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 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 ffff88809e918240 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 96 bytes inside of 2048-byte region [ffff88809e918240, ffff88809e918a40) The buggy address belongs to the page: page:ffffea00027a4600 count:1 mapcount:0 mapping:ffff88812c39cc40 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea00021ea508 ffffea0002792888 ffff88812c39cc40 raw: 0000000000000000 ffff88809e918240 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809e918180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809e918200: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff88809e918280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809e918300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809e918380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================