On Mon, Aug 12, 2019 at 2:18 PM syzbot <syzbot+45a53506b65321c1fe91@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: e96407b4 usb-fuzzer: main usb gadget fuzzer driver > git tree: https://github.com/google/kasan.git usb-fuzzer > console output: https://syzkaller.appspot.com/x/log.txt?x=1390791c600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e > dashboard link: https://syzkaller.appspot.com/bug?extid=45a53506b65321c1fe91 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c78cd2600000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1395b40e600000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+45a53506b65321c1fe91@xxxxxxxxxxxxxxxxxxxxxxxxx > > usb 1-1: config 1 interface 0 altsetting 0 has 0 endpoint descriptors, > different from the interface descriptor's value: 18 > usb 1-1: New USB device found, idVendor=0525, idProduct=a4a1, bcdDevice= > 0.40 > usb 1-1: New USB device strings: Mfr=6, Product=0, SerialNumber=0 > ================================================================== > BUG: KASAN: slab-out-of-bounds in memcmp+0xa6/0xb0 lib/string.c:904 > Read of size 1 at addr ffff8881d4262f3b by task kworker/1:2/83 > > CPU: 1 PID: 83 Comm: kworker/1:2 Not tainted 5.3.0-rc2+ #25 > 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+0xca/0x13e lib/dump_stack.c:113 > print_address_description+0x6a/0x32c mm/kasan/report.c:351 > __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482 > kasan_report+0xe/0x12 mm/kasan/common.c:612 > memcmp+0xa6/0xb0 lib/string.c:904 > memcmp include/linux/string.h:400 [inline] > usbnet_generic_cdc_bind+0x71b/0x17c0 drivers/net/usb/cdc_ether.c:225 > usbnet_ether_cdc_bind drivers/net/usb/cdc_ether.c:322 [inline] > usbnet_cdc_bind+0x20/0x1a0 drivers/net/usb/cdc_ether.c:430 > usbnet_probe+0xb43/0x23d0 drivers/net/usb/usbnet.c:1722 > usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 > really_probe+0x281/0x650 drivers/base/dd.c:548 > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 > bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 > __device_attach+0x217/0x360 drivers/base/dd.c:882 > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > device_add+0xae6/0x16f0 drivers/base/core.c:2114 > usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 > generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 > usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 > really_probe+0x281/0x650 drivers/base/dd.c:548 > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 > bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 > __device_attach+0x217/0x360 drivers/base/dd.c:882 > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > device_add+0xae6/0x16f0 drivers/base/core.c:2114 > usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 > hub_port_connect drivers/usb/core/hub.c:5098 [inline] > hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] > port_event drivers/usb/core/hub.c:5359 [inline] > hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 > process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 > worker_thread+0x96/0xe20 kernel/workqueue.c:2415 > kthread+0x318/0x420 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > Allocated by task 83: > save_stack+0x1b/0x80 mm/kasan/common.c:69 > set_track mm/kasan/common.c:77 [inline] > __kasan_kmalloc mm/kasan/common.c:487 [inline] > __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:460 > kmalloc include/linux/slab.h:557 [inline] > usb_get_configuration+0x30c/0x3070 drivers/usb/core/config.c:857 > usb_enumerate_device drivers/usb/core/hub.c:2369 [inline] > usb_new_device+0xd3/0x160 drivers/usb/core/hub.c:2505 > hub_port_connect drivers/usb/core/hub.c:5098 [inline] > hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] > port_event drivers/usb/core/hub.c:5359 [inline] > hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 > process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 > worker_thread+0x96/0xe20 kernel/workqueue.c:2415 > kthread+0x318/0x420 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > Freed by task 269: > save_stack+0x1b/0x80 mm/kasan/common.c:69 > set_track mm/kasan/common.c:77 [inline] > __kasan_slab_free+0x130/0x180 mm/kasan/common.c:449 > slab_free_hook mm/slub.c:1423 [inline] > slab_free_freelist_hook mm/slub.c:1470 [inline] > slab_free mm/slub.c:3012 [inline] > kfree+0xe4/0x2f0 mm/slub.c:3953 > kobject_uevent_env+0x294/0x1160 lib/kobject_uevent.c:624 > kobject_synth_uevent+0x70a/0x81e lib/kobject_uevent.c:208 > uevent_store+0x20/0x50 drivers/base/core.c:1244 > dev_attr_store+0x50/0x80 drivers/base/core.c:947 > sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:138 > kernfs_fop_write+0x2b0/0x470 fs/kernfs/file.c:315 > __vfs_write+0x76/0x100 fs/read_write.c:494 > vfs_write+0x262/0x5c0 fs/read_write.c:558 > ksys_write+0x127/0x250 fs/read_write.c:611 > do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8881d4262f00 > which belongs to the cache kmalloc-64 of size 64 > The buggy address is located 59 bytes inside of > 64-byte region [ffff8881d4262f00, ffff8881d4262f40) > The buggy address belongs to the page: > page:ffffea0007509880 refcount:1 mapcount:0 mapping:ffff8881da003180 > index:0x0 > flags: 0x200000000000200(slab) > raw: 0200000000000200 ffffea00074d1f00 0000001800000018 ffff8881da003180 > raw: 0000000000000000 00000000802a002a 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8881d4262e00: fb fb fb fb fc fc fc fc 00 00 00 00 00 00 fc fc > ffff8881d4262e80: fc fc fc fc fb fb fb fb fb fb fb fb fc fc fc fc > > ffff8881d4262f00: 00 00 00 00 00 00 00 03 fc fc fc fc fb fb fb fb > ^ > ffff8881d4262f80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc > ffff8881d4263000: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fb fb > ================================================================== This one is funny, we do sizeof(struct usb_cdc_mdlm_desc *) instead of sizeof(struct usb_cdc_mdlm_desc) and the same for usb_cdc_mdlm_detail_desc in cdc_parse_cdc_header(). > > > --- > 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 > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000487b44058fea845c%40google.com.
