------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 24873 at lib/refcount.c:25 refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 24873 Comm: syz-executor.1 Not tainted 5.15.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25 Code: c7 60 d4 b3 8a 31 c0 e8 21 0f 3d fd 0f 0b eb a3 e8 b8 d7 71 fd c6 05 e5 0c b8 09 01 48 c7 c7 c0 d4 b3 8a 31 c0 e8 03 0f 3d fd <0f> 0b eb 85 e8 9a d7 71 fd c6 05 c8 0c b8 09 01 48 c7 c7 20 d5 b3 RSP: 0018:ffffc90005ba7a08 EFLAGS: 00010246 RAX: 8bbc820dda141f00 RBX: 0000000000000002 RCX: 0000000000040000 RDX: ffffc90005cba000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 0000000000000002 R08: ffffffff81682012 R09: ffffed10173857a8 R10: ffffed10173857a8 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888026676968 R14: ffff8880807a3c00 R15: 0000000000000067 FS: 00007ff80a950700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff8bce7e000 CR3: 000000003f25c000 CR4: 00000000001526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] sock_hold include/net/sock.h:702 [inline] sco_conn_del+0x242/0x2f0 net/bluetooth/sco.c:193 hci_disconn_cfm include/net/bluetooth/hci_core.h:1518 [inline] hci_conn_hash_flush+0x112/0x240 net/bluetooth/hci_conn.c:1608 hci_dev_do_close+0x93e/0xeb0 net/bluetooth/hci_core.c:1793 hci_rfkill_set_block+0x10f/0x180 net/bluetooth/hci_core.c:2233 rfkill_set_block+0x1f1/0x440 net/rfkill/core.c:344 rfkill_fop_write+0x5a4/0x760 net/rfkill/core.c:1268 vfs_write+0x327/0xe90 fs/read_write.c:592 ksys_write+0x18f/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7ff80d3d9739 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff80a950188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff80d4ddf80 RCX: 00007ff80d3d9739 RDX: 0000000000000008 RSI: 0000000020000040 RDI: 0000000000000005 RBP: 00007ff80d433cc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff80d4ddf80 R13: 00007ffd42a4f7df R14: 00007ff80a950300 R15: 0000000000022000