On Thu, Jun 6, 2019 at 11:42 AM syzbot <syzbot+a106a5b084a6890d2607@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: f75e4cfe kmsan: use kmsan_handle_urb() in urb.c > git tree: kmsan > console output: https://syzkaller.appspot.com/x/log.txt?x=12f8b01ea00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=602468164ccdc30a > dashboard link: https://syzkaller.appspot.com/bug?extid=a106a5b084a6890d2607 > compiler: clang version 9.0.0 (/home/glider/llvm/clang > 06d00afa61eef8f7f501ebdb4e8612ea43ec2d78) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14f746f2a00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=153072d2a00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+a106a5b084a6890d2607@xxxxxxxxxxxxxxxxxxxxxxxxx > > usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 > usb 1-1: config 0 descriptor?? > usb 1-1: reset high-speed USB device number 2 using dummy_hcd > usb 1-1: device descriptor read/64, error -71 > ieee80211 phy3: rt2x00usb_vendor_request: Error - Vendor Request 0x09 > failed for offset 0x0000 with error -71 > ieee80211 phy3: rt2x00usb_vendor_request: Error - Vendor Request 0x07 As this line suggests: > failed for offset 0x04d0 with error -71 , rt2x00usb_vendor_req_buff_lock() fails with error -71, which means it doesn't initialize the buffer. But rt2500usb_register_read_lock() ignores that status code and just assumes the data is always initialized. > ================================================================== > BUG: KMSAN: uninit-value in rt2500usb_regbusy_read > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:116 [inline] > BUG: KMSAN: uninit-value in rt2500usb_bbp_read+0x174/0x640 > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:172 > CPU: 1 PID: 4943 Comm: kworker/1:2 Not tainted 5.1.0+ #1 > 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+0x191/0x1f0 lib/dump_stack.c:113 > kmsan_report+0x130/0x2a0 mm/kmsan/kmsan.c:622 > __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310 > rt2500usb_regbusy_read drivers/net/wireless/ralink/rt2x00/rt2500usb.c:116 > [inline] > rt2500usb_bbp_read+0x174/0x640 > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:172 > rt2500usb_validate_eeprom > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1387 [inline] > rt2500usb_probe_hw+0x3b1/0x2230 > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1764 > rt2x00lib_probe_dev+0xb81/0x3090 > drivers/net/wireless/ralink/rt2x00/rt2x00dev.c:1427 > rt2x00usb_probe+0x7c7/0xf70 > drivers/net/wireless/ralink/rt2x00/rt2x00usb.c:837 > rt2500usb_probe+0x50/0x60 > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1977 > usb_probe_interface+0xd66/0x1320 drivers/usb/core/driver.c:361 > really_probe+0xdae/0x1d80 drivers/base/dd.c:513 > driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671 > __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778 > bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454 > __device_attach+0x454/0x730 drivers/base/dd.c:844 > device_initial_probe+0x4a/0x60 drivers/base/dd.c:891 > bus_probe_device+0x137/0x390 drivers/base/bus.c:514 > device_add+0x288d/0x30e0 drivers/base/core.c:2106 > usb_set_configuration+0x30dc/0x3750 drivers/usb/core/message.c:2027 > generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210 > usb_probe_device+0x14c/0x200 drivers/usb/core/driver.c:266 > really_probe+0xdae/0x1d80 drivers/base/dd.c:513 > driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671 > __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778 > bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454 > __device_attach+0x454/0x730 drivers/base/dd.c:844 > device_initial_probe+0x4a/0x60 drivers/base/dd.c:891 > bus_probe_device+0x137/0x390 drivers/base/bus.c:514 > device_add+0x288d/0x30e0 drivers/base/core.c:2106 > usb_new_device+0x23e5/0x2ff0 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+0x48d1/0x7290 drivers/usb/core/hub.c:5432 > process_one_work+0x1572/0x1f00 kernel/workqueue.c:2269 > worker_thread+0x111b/0x2460 kernel/workqueue.c:2415 > kthread+0x4b5/0x4f0 kernel/kthread.c:254 > ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355 > > Local variable description: ----reg.i.i@rt2500usb_bbp_read > Variable was created at: > rt2500usb_register_read_lock > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:72 [inline] > rt2500usb_regbusy_read drivers/net/wireless/ralink/rt2x00/rt2500usb.c:115 > [inline] > rt2500usb_bbp_read+0xa4/0x640 > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:172 > rt2500usb_validate_eeprom > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1387 [inline] > rt2500usb_probe_hw+0x3b1/0x2230 > drivers/net/wireless/ralink/rt2x00/rt2500usb.c:1764 > ================================================================== > > > --- > This bug 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 bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
