------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 2868 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 2868 Comm: krfcommd Not tainted 5.18.0-rc6-syzkaller-00009-gfeb9c5e19e91 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25 Code: 09 31 ff 89 de e8 97 44 81 fd 84 db 0f 85 36 ff ff ff e8 aa 40 81 fd 48 c7 c7 80 61 26 8a c6 05 0f 00 ad 09 01 e8 e7 f5 30 05 <0f> 0b e9 17 ff ff ff e8 8b 40 81 fd 0f b6 1d f4 ff ac 09 31 ff 89 RSP: 0018:ffffc9002186fba0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88801ccac0c0 RSI: ffffffff815f4a18 RDI: fffff5200430df66 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff815ef3ee R11: 0000000000000000 R12: ffff88802ace4080 R13: ffff88802ace4000 R14: dffffc0000000000 R15: ffff888020938000 FS: 0000000000000000(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556cac708 CR3: 000000000ba8e000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:199 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] sock_hold include/net/sock.h:726 [inline] bt_accept_dequeue+0x302/0x630 net/bluetooth/af_bluetooth.c:206 l2cap_sock_accept+0x290/0x5a0 net/bluetooth/l2cap_sock.c:368 kernel_accept+0x178/0x350 net/socket.c:3410 rfcomm_accept_connection net/bluetooth/rfcomm/core.c:1967 [inline] rfcomm_process_sessions net/bluetooth/rfcomm/core.c:2026 [inline] rfcomm_run+0x37d/0x4a30 net/bluetooth/rfcomm/core.c:2122 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298