================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x2c57/0x3f20 kernel/locking/lockdep.c:3369 Read of size 8 at addr ffff88809ad801e0 by task kworker/0:1/24 CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.14.216-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:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430 __lock_acquire+0x2c57/0x3f20 kernel/locking/lockdep.c:3369 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:176 spin_lock_bh include/linux/spinlock.h:322 [inline] lock_sock_nested+0x39/0x100 net/core/sock.c:2788 l2cap_sock_teardown_cb+0x93/0x650 net/bluetooth/l2cap_sock.c:1341 l2cap_chan_del+0xaf/0x950 net/bluetooth/l2cap_core.c:599 l2cap_chan_close+0x103/0x870 net/bluetooth/l2cap_core.c:757 l2cap_chan_timeout+0x143/0x2a0 net/bluetooth/l2cap_core.c:430 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Allocated by task 10865: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] l2cap_chan_create+0x3e/0x400 net/bluetooth/l2cap_core.c:444 l2cap_sock_alloc.constprop.0+0x16c/0x210 net/bluetooth/l2cap_sock.c:1633 l2cap_sock_create+0xf0/0x1a0 net/bluetooth/l2cap_sock.c:1664 bt_sock_create+0x13b/0x280 net/bluetooth/af_bluetooth.c:130 __sock_create+0x303/0x620 net/socket.c:1275 sock_create net/socket.c:1315 [inline] SYSC_socket net/socket.c:1345 [inline] SyS_socket+0xd1/0x1b0 net/socket.c:1325 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 10865: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 l2cap_chan_destroy net/bluetooth/l2cap_core.c:482 [inline] kref_put include/linux/kref.h:70 [inline] l2cap_chan_put+0x1c2/0x250 net/bluetooth/l2cap_core.c:496 l2cap_sock_release+0x1e2/0x280 net/bluetooth/l2cap_sock.c:1213 __sock_release+0xcd/0x2b0 net/socket.c:602 sock_close+0x15/0x20 net/socket.c:1139 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 get_signal+0x18a3/0x1ca0 kernel/signal.c:2234 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff88809ad80140 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [ffff88809ad80140, ffff88809ad80940) The buggy address belongs to the page: page:ffffea00026b6000 count:1 mapcount:0 mapping:ffff88809ad80140 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffff88809ad80140 0000000000000000 0000000100000003 raw: ffffea000263dda0 ffffea00026487a0 ffff88813fe80c40 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809ad80080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809ad80100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff88809ad80180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809ad80200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809ad80280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================