Hello, syzbot found the following issue on: HEAD commit: 528dd46d0fc3 Merge tag 'net-6.10-rc8-2' of git://git.kerne.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=108f8c0d980000 kernel config: https://syzkaller.appspot.com/x/.config?x=b63b35269462a0e0 dashboard link: https://syzkaller.appspot.com/bug?extid=e8c4df4ec92aa7f4e3a2 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/e86e44bbf25e/disk-528dd46d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/601010d0e1b0/vmlinux-528dd46d.xz kernel image: https://storage.googleapis.com/syzbot-assets/c98ac3165731/bzImage-528dd46d.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e8c4df4ec92aa7f4e3a2@xxxxxxxxxxxxxxxxxxxxxxxxx usb 18-1: new SuperSpeed USB device number 27 using vhci_hcd ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 784 at lib/refcount.c:25 refcount_warn_saturate+0x13a/0x1d0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 784 Comm: kworker/1:2 Not tainted 6.10.0-rc7-syzkaller-00254-g528dd46d0fc3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: usb_hub_wq hub_event RIP: 0010:refcount_warn_saturate+0x13a/0x1d0 lib/refcount.c:25 Code: 80 d6 1f 8c e8 37 16 a9 fc 90 0f 0b 90 90 eb b9 e8 5b e8 e6 fc c6 05 64 bf e8 0a 01 90 48 c7 c7 e0 d6 1f 8c e8 17 16 a9 fc 90 <0f> 0b 90 90 eb 99 e8 3b e8 e6 fc c6 05 45 bf e8 0a 01 90 48 c7 c7 RSP: 0018:ffffc9000384f270 EFLAGS: 00010046 RAX: 984309741ee81900 RBX: ffff8880257470e0 RCX: ffff88801fb85a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000002 R08: ffffffff81585882 R09: fffffbfff1c39994 R10: dffffc0000000000 R11: fffffbfff1c39994 R12: ffff8880242d8408 R13: ffff8880242d8448 R14: ffff8880257470e0 R15: ffff8880257470a8 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000005845d99c CR3: 0000000062b7a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000400 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: <TASK> __refcount_inc include/linux/refcount.h:241 [inline] refcount_inc include/linux/refcount.h:258 [inline] kref_get include/linux/kref.h:45 [inline] kobject_get+0xfd/0x120 lib/kobject.c:643 usb_get_dev+0x23/0x40 drivers/usb/core/usb.c:765 vhci_urb_enqueue+0x5bf/0xef0 drivers/usb/usbip/vhci_hcd.c:785 usb_hcd_submit_urb+0x36c/0x1e80 drivers/usb/core/hcd.c:1533 usb_start_wait_urb+0x113/0x520 drivers/usb/core/message.c:59 usb_internal_control_msg drivers/usb/core/message.c:103 [inline] usb_control_msg+0x2b1/0x4c0 drivers/usb/core/message.c:154 get_bMaxPacketSize0 drivers/usb/core/hub.c:4805 [inline] hub_port_init+0x1156/0x2670 drivers/usb/core/hub.c:5066 hub_port_connect drivers/usb/core/hub.c:5450 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x295f/0x5150 drivers/usb/core/hub.c:5903 process_one_work kernel/workqueue.c:3248 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329 worker_thread+0x86d/0xd50 kernel/workqueue.c:3409 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </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. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
