================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x40d0/0x5570 kernel/locking/lockdep.c:4296 Read of size 8 at addr ffff888092dc90a0 by task kworker/1:4/8260 CPU: 1 PID: 8260 Comm: kworker/1:4 Not tainted 5.9.0-rc3-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+0x198/0x1fd lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 __lock_acquire+0x40d0/0x5570 kernel/locking/lockdep.c:4296 lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:359 [inline] lock_sock_nested+0x3b/0x110 net/core/sock.c:3048 l2cap_sock_teardown_cb+0x88/0x400 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_del+0xad/0x1300 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0x118/0xb10 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x173/0x450 net/bluetooth/l2cap_core.c:436 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Allocated by task 10361: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x1b0/0x310 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] sk_prot_alloc+0x17a/0x300 net/core/sock.c:1685 sk_alloc+0x32/0xbd0 net/core/sock.c:1739 l2cap_sock_alloc.constprop.0+0x31/0x230 net/bluetooth/l2cap_sock.c:1790 l2cap_sock_create+0x110/0x1b0 net/bluetooth/l2cap_sock.c:1836 bt_sock_create+0x154/0x2a0 net/bluetooth/af_bluetooth.c:130 __sock_create+0x3ca/0x740 net/socket.c:1427 sock_create net/socket.c:1478 [inline] __sys_socket+0xef/0x200 net/socket.c:1520 __do_sys_socket net/socket.c:1529 [inline] __se_sys_socket net/socket.c:1527 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1527 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 10361: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kfree+0x10e/0x2b0 mm/slab.c:3756 sk_prot_free net/core/sock.c:1722 [inline] __sk_destruct+0x63b/0x860 net/core/sock.c:1807 sk_destruct+0xbd/0xe0 net/core/sock.c:1822 __sk_free+0xef/0x3d0 net/core/sock.c:1833 sk_free+0x78/0xa0 net/core/sock.c:1844 sock_put include/net/sock.h:1781 [inline] l2cap_sock_kill+0x14e/0x180 net/bluetooth/l2cap_sock.c:1219 l2cap_sock_release+0x171/0x1d0 net/bluetooth/l2cap_sock.c:1389 __sock_release+0xcd/0x280 net/socket.c:596 sock_close+0x18/0x20 net/socket.c:1277 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:141 get_signal+0xd89/0x1f00 kernel/signal.c:2561 arch_do_signal+0x82/0x2520 arch/x86/kernel/signal.c:811 exit_to_user_mode_loop kernel/entry/common.c:136 [inline] exit_to_user_mode_prepare+0x1ae/0x200 kernel/entry/common.c:167 syscall_exit_to_user_mode+0x7e/0x2e0 kernel/entry/common.c:242 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888092dc9000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [ffff888092dc9000, ffff888092dc9800) The buggy address belongs to the page: page:0000000047ef5f8d refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x92dc9 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00027c0648 ffffea00029feb48 ffff8880aa040800 raw: 0000000000000000 ffff888092dc9000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888092dc8f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888092dc9000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888092dc9080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888092dc9100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888092dc9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================