syzbot

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refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 9913 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 9913 Comm: syz-executor.1 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Code: e9 db fe ff ff 48 89 df e8 2c c2 ea fd e9 8a fe ff ff e8 72 6a a7 fd 48 c7 c7 e0 b2 c1 89 c6 05 dc 3a e6 09 01 e8 ee 74 fb 04 <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55
RSP: 0018:ffffc9000aacfcd0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888043e30000 RSI: ffffffff815bb075 RDI: fffff52001559f8c
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815b4eae R11: 0000000000000000 R12: 0000000000000000
R13: ffff8881445bc018 R14: ffff8881445bc000 R15: ffff888035fb8e38
FS:  00000000033cc400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007facd239b028 CR3: 000000002f293000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_sub_and_test include/linux/refcount.h:283 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 kref_put include/linux/kref.h:64 [inline]
 nfc_llcp_local_put net/nfc/llcp_core.c:183 [inline]
 nfc_llcp_local_put+0x1ab/0x200 net/nfc/llcp_core.c:178
 llcp_sock_destruct+0x81/0x150 net/nfc/llcp_sock.c:950
 __sk_destruct+0x4b/0x900 net/core/sock.c:1795
 sk_destruct+0xbd/0xe0 net/core/sock.c:1839
 __sk_free+0xef/0x3d0 net/core/sock.c:1850
 sk_free+0x78/0xa0 net/core/sock.c:1861
 sock_put include/net/sock.h:1807 [inline]
 llcp_sock_release+0x3c9/0x580 net/nfc/llcp_sock.c:644
 __sock_release+0xcd/0x280 net/socket.c:599
 sock_close+0x18/0x20 net/socket.c:1258
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:161
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x272/0x280 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x41940b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffeb9c7a050 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 000000000041940b
RDX: 0000000000570838 RSI: 0000000000000001 RDI: 0000000000000004
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b320200fc
R10: 00007ffeb9c7a140 R11: 0000000000000293 R12: 0000000000016289
R13: 00000000000003e8 R14: 000000000056bf60 R15: 0000000000016272