Hello, syzbot found the following issue on: HEAD commit: ce55c22ec8b2 Merge tag 'net-6.6-rc7' of git://git.kernel.o.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=17645b9d680000 kernel config: https://syzkaller.appspot.com/x/.config?x=849fe52ba7c6d78a dashboard link: https://syzkaller.appspot.com/bug?extid=f93d183bc91522d90de9 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15bcf805680000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1122c7b1680000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/f6762ae43666/disk-ce55c22e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/9b2c191a2c66/vmlinux-ce55c22e.xz kernel image: https://storage.googleapis.com/syzbot-assets/931e7d3d48a1/bzImage-ce55c22e.xz The issue was bisected to: commit 92d4abd66f7080075793970fc8f241239e58a9e7 Author: Arkadiusz Bokowy <arkadiusz.bokowy@xxxxxxxxx> Date: Wed Sep 20 15:30:07 2023 +0000 Bluetooth: vhci: Fix race when opening vhci device bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=107ea899680000 final oops: https://syzkaller.appspot.com/x/report.txt?x=127ea899680000 console output: https://syzkaller.appspot.com/x/log.txt?x=147ea899680000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f93d183bc91522d90de9@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 92d4abd66f70 ("Bluetooth: vhci: Fix race when opening vhci device") ====================================================== WARNING: possible circular locking dependency detected 6.6.0-rc6-syzkaller-00182-gce55c22ec8b2 #0 Not tainted ------------------------------------------------------ syz-executor269/5035 is trying to acquire lock: ffff8880737b4dc0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: __flush_work+0xe9/0xac0 kernel/workqueue.c:3403 but task is already holding lock: ffff8880737b50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] ffff8880737b50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_rfkill_set_block+0x12d/0x210 net/bluetooth/hci_core.c:956 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&hdev->req_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747 hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] hci_rfkill_set_block+0x12d/0x210 net/bluetooth/hci_core.c:956 rfkill_set_block+0x1e7/0x430 net/rfkill/core.c:346 rfkill_fop_write+0x5bb/0x790 net/rfkill/core.c:1305 vfs_write+0x286/0xaf0 fs/read_write.c:582 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #2 (rfkill_global_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747 rfkill_register+0x34/0x8c0 net/rfkill/core.c:1075 hci_register_dev+0x4e3/0xa40 net/bluetooth/hci_core.c:2656 __vhci_create_device drivers/bluetooth/hci_vhci.c:437 [inline] vhci_create_device+0x3ba/0x720 drivers/bluetooth/hci_vhci.c:478 vhci_get_user drivers/bluetooth/hci_vhci.c:535 [inline] vhci_write+0x3c7/0x480 drivers/bluetooth/hci_vhci.c:615 call_write_iter include/linux/fs.h:1956 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x782/0xaf0 fs/read_write.c:584 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (&data->open_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747 vhci_send_frame+0x8e/0xf0 drivers/bluetooth/hci_vhci.c:78 hci_send_frame+0x1ef/0x370 net/bluetooth/hci_core.c:3039 hci_sched_acl_pkt net/bluetooth/hci_core.c:3651 [inline] hci_sched_acl net/bluetooth/hci_core.c:3736 [inline] hci_tx_work+0xed4/0x1ef0 net/bluetooth/hci_core.c:3835 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x90f/0x1400 kernel/workqueue.c:2703 worker_thread+0xa5f/0xff0 kernel/workqueue.c:2784 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 -> #0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 __flush_work+0x102/0xac0 kernel/workqueue.c:3403 hci_dev_close_sync+0x237/0xfe0 net/bluetooth/hci_sync.c:4982 hci_dev_do_close net/bluetooth/hci_core.c:554 [inline] hci_rfkill_set_block+0x135/0x210 net/bluetooth/hci_core.c:956 rfkill_set_block+0x1e7/0x430 net/rfkill/core.c:346 rfkill_fop_write+0x5bb/0x790 net/rfkill/core.c:1305 vfs_write+0x286/0xaf0 fs/read_write.c:582 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: (work_completion)(&hdev->tx_work) --> rfkill_global_mutex --> &hdev->req_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&hdev->req_lock); lock(rfkill_global_mutex); lock(&hdev->req_lock); lock((work_completion)(&hdev->tx_work)); *** DEADLOCK *** 2 locks held by syz-executor269/5035: #0: ffffffff8e794ea8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x1a9/0x790 net/rfkill/core.c:1297 #1: ffff8880737b50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:552 [inline] #1: ffff8880737b50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_rfkill_set_block+0x12d/0x210 net/bluetooth/hci_core.c:956 stack backtrace: CPU: 1 PID: 5035 Comm: syz-executor269 Not tainted 6.6.0-rc6-syzkaller-00182-gce55c22ec8b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 __flush_work+0x102/0xac0 kernel/workqueue.c:3403 hci_dev_close_sync+0x237/0xfe0 net/bluetooth/hci_sync.c:4982 hci_dev_do_close net/bluetooth/hci_core.c:554 [inline] hci_rfkill_set_block+0x135/0x210 net/bluetooth/hci_core.c:956 rfkill_set_block+0x1e7/0x430 net/rfkill/core.c:346 rfkill_fop_write+0x5bb/0x790 net/rfkill/core.c:1305 vfs_write+0x286/0xaf0 fs/read_write.c:582 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f3ba6729479 Code: 48 83 c4 28 c3 e8 e7 18 00 00 0f 1f 80 00 00 00 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc064fec88 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f3ba6780043 RCX: 00007f3ba6729479 RDX: 0000000000000008 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00007ffc064fecd0 R08: 000000ff00fff650 R09: 000000ff00fff650 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc064fecb8 R13: 00007f3ba67ad5b0 R14: 0000000000000000 R15: 0000000000000001 </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. For information about bisection process see: https://goo.gl/tpsmEJ#bisection If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
