Hello, syzbot found the following issue on: HEAD commit: 9be9ed2612b5 Merge tag 'platform-drivers-x86-v5.18-4' of g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=164544f1f00000 kernel config: https://syzkaller.appspot.com/x/.config?x=3afe599903e2c6b6 dashboard link: https://syzkaller.appspot.com/bug?extid=fd86a41b17a416a37a75 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17285deaf00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15bd5d3ef00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fd86a41b17a416a37a75@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 2 PID: 3674 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25 Modules linked in: CPU: 2 PID: 3674 Comm: kworker/u19:1 Not tainted 5.18.0-rc6-syzkaller-00007-g9be9ed2612b5 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Workqueue: hci0 hci_rx_work 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:ffffc90002e17960 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8880187b2180 RSI: ffffffff815f4a18 RDI: fffff520005c2f1e RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff815ef3ee R11: 0000000000000000 R12: ffff88801c4a1000 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556dd1608 CR3: 00000000234d6000 CR4: 0000000000150ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __refcount_add include/linux/refcount.h:199 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] kref_get include/linux/kref.h:45 [inline] l2cap_chan_hold+0xff/0x120 net/bluetooth/l2cap_core.c:497 l2cap_global_chan_by_psm+0x3b1/0x4a0 net/bluetooth/l2cap_core.c:1986 l2cap_conless_channel net/bluetooth/l2cap_core.c:7611 [inline] l2cap_recv_frame+0x68d/0x8e60 net/bluetooth/l2cap_core.c:7681 l2cap_recv_acldata+0xa96/0xc10 net/bluetooth/l2cap_core.c:8394 hci_acldata_packet net/bluetooth/hci_core.c:3633 [inline] hci_rx_work+0x4d5/0xd60 net/bluetooth/hci_core.c:3824 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
