Re: INFO: trying to register non-static key in rtl_c2hcmd_launcher

From: Andrey Konovalov
Date: Tue May 28 2019 - 12:13:55 EST


On Fri, Apr 12, 2019 at 1:46 PM syzbot
<syzbot+1fcc5ef45175fc774231@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 9a33b369 usb-fuzzer: main usb gadget fuzzer driver
> git tree: https://github.com/google/kasan/tree/usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=14d4c1af200000
> kernel config: https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15
> dashboard link: https://syzkaller.appspot.com/bug?extid=1fcc5ef45175fc774231
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15b6f0f3200000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=140c7c2d200000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+1fcc5ef45175fc774231@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
> rtl_usb: reg 0xf0, usbctrl_vendorreq TimeOut! status:0xffffffb9 value=0x0
> rtl8192cu: Chip version 0x10
> rtl_usb: reg 0xa, usbctrl_vendorreq TimeOut! status:0xffffffb9 value=0x0
> rtl_usb: Too few input end points found
> INFO: trying to register non-static key.
> the code is fine but needs lockdep annotation.
> turning off the locking correctness validator.
> CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.1.0-rc4-319354-g9a33b36 #3
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Workqueue: usb_hub_wq hub_event
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0xe8/0x16e lib/dump_stack.c:113
> assign_lock_key kernel/locking/lockdep.c:786 [inline]
> register_lock_class+0x11b8/0x1250 kernel/locking/lockdep.c:1095
> __lock_acquire+0xfb/0x37c0 kernel/locking/lockdep.c:3582
> lock_acquire+0x10d/0x2f0 kernel/locking/lockdep.c:4211
> __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
> _raw_spin_lock_irqsave+0x44/0x60 kernel/locking/spinlock.c:152
> rtl_c2hcmd_launcher+0xd1/0x390
> drivers/net/wireless/realtek/rtlwifi/base.c:2344
> rtl_deinit_core+0x25/0x2d0 drivers/net/wireless/realtek/rtlwifi/base.c:574
> rtl_usb_probe.cold+0x861/0xa70
> drivers/net/wireless/realtek/rtlwifi/usb.c:1093
> usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
> really_probe+0x2da/0xb10 drivers/base/dd.c:509
> driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
> __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
> bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
> __device_attach+0x223/0x3a0 drivers/base/dd.c:844
> bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
> device_add+0xad2/0x16e0 drivers/base/core.c:2106
> usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
> generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
> usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
> really_probe+0x2da/0xb10 drivers/base/dd.c:509
> driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
> __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
> bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
> __device_attach+0x223/0x3a0 drivers/base/dd.c:844
> bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
> device_add+0xad2/0x16e0 drivers/base/core.c:2106
> usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
> hub_port_connect drivers/usb/core/hub.c:5089 [inline]
> hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
> port_event drivers/usb/core/hub.c:5350 [inline]
> hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432
> process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
> worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
> kthread+0x313/0x420 kernel/kthread.c:253
> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] SMP KASAN PTI
> CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.1.0-rc4-319354-g9a33b36 #3
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Workqueue: usb_hub_wq hub_event
> RIP: 0010:rtl_free_entries_from_scan_list
> drivers/net/wireless/realtek/rtlwifi/base.c:1933 [inline]
> RIP: 0010:rtl_deinit_core+0x84/0x2d0
> drivers/net/wireless/realtek/rtlwifi/base.c:575
> Code: 4c 89 f2 48 c1 ea 03 80 3c 02 00 0f 85 52 02 00 00 4d 8b bc 24 c8 c4
> 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f
> 85 22 02 00 00 4d 39 f7 4d 8b 2f 4c 89 ff 0f 84 3d
> RSP: 0018:ffff8880a84b7278 EFLAGS: 00010246
> RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 1ffffffff27960ab
> RDX: 0000000000000000 RSI: ffffffff88da7445 RDI: ffff888093c00b68
> RBP: ffff888093c00b20 R08: ffff8880a8498000 R09: ffffed101278051d
> R10: ffffed101278051c R11: ffff888093c028e3 R12: ffff888093c02540
> R13: ffff88821add7848 R14: ffff888093c0ea08 R15: 0000000000000000
> FS: 0000000000000000(0000) GS:ffff8880ad000000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fd01db19000 CR3: 000000009c01a000 CR4: 00000000001406f0
> Call Trace:
> rtl_usb_probe.cold+0x861/0xa70
> drivers/net/wireless/realtek/rtlwifi/usb.c:1093
> usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
> really_probe+0x2da/0xb10 drivers/base/dd.c:509
> driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
> __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
> bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
> __device_attach+0x223/0x3a0 drivers/base/dd.c:844
> bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
> device_add+0xad2/0x16e0 drivers/base/core.c:2106
> usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
> generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
> usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
> really_probe+0x2da/0xb10 drivers/base/dd.c:509
> driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
> __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
> bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
> __device_attach+0x223/0x3a0 drivers/base/dd.c:844
> bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
> device_add+0xad2/0x16e0 drivers/base/core.c:2106
> usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
> hub_port_connect drivers/usb/core/hub.c:5089 [inline]
> hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
> port_event drivers/usb/core/hub.c:5350 [inline]
> hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432
> process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
> worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
> kthread+0x313/0x420 kernel/kthread.c:253
> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> Modules linked in:
> ---[ end trace 38ab7b2a1beef511 ]---
> RIP: 0010:rtl_free_entries_from_scan_list
> drivers/net/wireless/realtek/rtlwifi/base.c:1933 [inline]
> RIP: 0010:rtl_deinit_core+0x84/0x2d0
> drivers/net/wireless/realtek/rtlwifi/base.c:575
> Code: 4c 89 f2 48 c1 ea 03 80 3c 02 00 0f 85 52 02 00 00 4d 8b bc 24 c8 c4
> 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f
> 85 22 02 00 00 4d 39 f7 4d 8b 2f 4c 89 ff 0f 84 3d
> RSP: 0018:ffff8880a84b7278 EFLAGS: 00010246
> RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 1ffffffff27960ab
> RDX: 0000000000000000 RSI: ffffffff88da7445 RDI: ffff888093c00b68
> RBP: ffff888093c00b20 R08: ffff8880a8498000 R09: ffffed101278051d
> R10: ffffed101278051c R11: ffff888093c028e3 R12: ffff888093c02540
> R13: ffff88821add7848 R14: ffff888093c0ea08 R15: 0000000000000000
> FS: 0000000000000000(0000) GS:ffff8880ad000000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fd01db19000 CR3: 000000009c01a000 CR4: 00000000001406f0

This is currently the top crasher on the USB syzbot fuzzing instance.

AFAICT the issue is that rtl_usb_probe() can goto error_out and call
rtl_deinit_core()->rtl_c2hcmd_launcher()->spin_lock_irqsave(&rtlpriv->locks.c2hcmd_lock)
before locks.c2hcmd_lock is initialized by rtl_init_core().

>
>
> ---
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