INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 0 PID: 9033 Comm: kworker/0:7 Not tainted 5.8.0-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+0x18f/0x20d lib/dump_stack.c:118 assign_lock_key kernel/locking/lockdep.c:894 [inline] register_lock_class+0x157d/0x1630 kernel/locking/lockdep.c:1206 __lock_acquire+0xf9/0x5640 kernel/locking/lockdep.c:4305 lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __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 ================================================================== BUG: KASAN: use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline] BUG: KASAN: use-after-free in do_raw_spin_lock+0x262/0x2b0 kernel/locking/spinlock_debug.c:112 Read of size 4 at addr ffff88805e14f08c by task kworker/0:7/9033 CPU: 0 PID: 9033 Comm: kworker/0:7 Not tainted 5.8.0-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+0x18f/0x20d 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 debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline] do_raw_spin_lock+0x262/0x2b0 kernel/locking/spinlock_debug.c:112 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 21284: 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 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0xae/0x550 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1085 [inline] _sctp_make_chunk+0x50/0x260 net/sctp/sm_make_chunk.c:1398 sctp_make_data net/sctp/sm_make_chunk.c:1430 [inline] sctp_make_datafrag_empty+0x164/0x230 net/sctp/sm_make_chunk.c:740 sctp_datamsg_from_user+0x615/0x11e0 net/sctp/chunk.c:262 sctp_sendmsg_to_asoc+0xbee/0x2090 net/sctp/socket.c:1841 sctp_sendmsg+0x1025/0x1cf0 net/sctp/socket.c:2013 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:671 __sys_sendto+0x21c/0x320 net/socket.c:1992 __do_sys_sendto net/socket.c:2004 [inline] __se_sys_sendto net/socket.c:2000 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2000 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 21284: 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+0x103/0x2c0 mm/slab.c:3756 skb_free_head net/core/skbuff.c:590 [inline] skb_release_data+0x6d9/0x910 net/core/skbuff.c:610 skb_release_all net/core/skbuff.c:664 [inline] __kfree_skb net/core/skbuff.c:678 [inline] consume_skb net/core/skbuff.c:837 [inline] consume_skb+0xc2/0x160 net/core/skbuff.c:831 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1458 [inline] sctp_chunk_put+0x1c0/0x2d0 net/sctp/sm_make_chunk.c:1485 sctp_datamsg_destroy net/sctp/chunk.c:111 [inline] sctp_datamsg_put+0x12d/0x5d0 net/sctp/chunk.c:128 sctp_chunk_free+0x42/0x60 net/sctp/sm_make_chunk.c:1470 __sctp_outq_teardown+0x6fe/0xc30 net/sctp/outqueue.c:257 sctp_association_free+0x212/0x7b0 net/sctp/associola.c:339 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:930 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1318 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline] sctp_do_sm+0x3838/0x4d80 net/sctp/sm_sideeffect.c:1156 sctp_primitive_SHUTDOWN+0x9b/0xc0 net/sctp/primitive.c:89 sctp_close+0x3d9/0x8b0 net/sctp/socket.c:1511 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:475 __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:135 get_signal+0xd6c/0x1ee0 kernel/signal.c:2547 arch_do_signal+0x82/0x2520 arch/x86/kernel/signal.c:811 exit_to_user_mode_loop kernel/entry/common.c:135 [inline] exit_to_user_mode_prepare+0x15d/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Last call_rcu(): kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_record_aux_stack+0x82/0xb0 mm/kasan/generic.c:346 __call_rcu kernel/rcu/tree.c:2894 [inline] call_rcu+0x14f/0x7e0 kernel/rcu/tree.c:2968 netlink_release+0xd43/0x1cf0 net/netlink/af_netlink.c:802 __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:135 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:139 [inline] exit_to_user_mode_prepare+0x195/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88805e14f000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 140 bytes inside of 2048-byte region [ffff88805e14f000, ffff88805e14f800) The buggy address belongs to the page: page:000000006002c7f1 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e14f flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002438308 ffffea00027a9d48 ffff8880aa040800 raw: 0000000000000000 ffff88805e14f000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805e14ef80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805e14f000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805e14f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805e14f100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805e14f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================