On Mon, Apr 29, 2019 at 2:06 PM syzbot <syzbot+a9fefd18c7b240f19c54@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 43151d6c 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=139ac37f200000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4183eeef650d1234 > dashboard link: https://syzkaller.appspot.com/bug?extid=a9fefd18c7b240f19c54 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17f3b338a00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+a9fefd18c7b240f19c54@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KASAN: slab-out-of-bounds in hex_string+0x418/0x4b0 lib/vsprintf.c:975 > Read of size 1 at addr ffff88821a41bd38 by task kworker/0:1/12 > > CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.1.0-rc3-319004-g43151d6 #6 > 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 > print_address_description+0x6c/0x236 mm/kasan/report.c:187 > kasan_report.cold+0x1a/0x3c mm/kasan/report.c:317 > hex_string+0x418/0x4b0 lib/vsprintf.c:975 > pointer+0x460/0x910 lib/vsprintf.c:1985 > vsnprintf+0x5a0/0x16b0 lib/vsprintf.c:2400 > pointer+0x60b/0x910 lib/vsprintf.c:2038 > vsnprintf+0x5a0/0x16b0 lib/vsprintf.c:2400 > vscnprintf+0x29/0x80 lib/vsprintf.c:2499 > vprintk_store+0x45/0x4b0 kernel/printk/printk.c:1900 > vprintk_emit+0x210/0x5a0 kernel/printk/printk.c:1957 > dev_vprintk_emit+0x50e/0x553 drivers/base/core.c:3185 > dev_printk_emit+0xbf/0xf6 drivers/base/core.c:3196 > __dev_printk+0x1ed/0x215 drivers/base/core.c:3208 > _dev_info+0xdc/0x10e drivers/base/core.c:3254 > dlfb_parse_vendor_descriptor drivers/video/fbdev/udlfb.c:1532 [inline] > dlfb_usb_probe.cold+0xb96/0x1701 drivers/video/fbdev/udlfb.c:1615 > 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:2023 > 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 > > Allocated by task 12: > set_track mm/kasan/common.c:87 [inline] > __kasan_kmalloc mm/kasan/common.c:497 [inline] > __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:470 > kmalloc include/linux/slab.h:552 [inline] > usb_get_configuration+0x313/0x32b0 drivers/usb/core/config.c:857 > usb_enumerate_device drivers/usb/core/hub.c:2367 [inline] > usb_new_device+0x2fe/0x450 drivers/usb/core/hub.c:2503 > 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 > > Freed by task 1464: > set_track mm/kasan/common.c:87 [inline] > __kasan_slab_free+0x130/0x180 mm/kasan/common.c:459 > slab_free_hook mm/slub.c:1429 [inline] > slab_free_freelist_hook+0x5e/0x140 mm/slub.c:1456 > slab_free mm/slub.c:3003 [inline] > kfree+0xce/0x290 mm/slub.c:3958 > single_release+0x91/0xb0 fs/seq_file.c:597 > __fput+0x2df/0x8c0 fs/file_table.c:278 > task_work_run+0x149/0x1c0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop+0x243/0x270 arch/x86/entry/common.c:166 > prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] > syscall_return_slowpath arch/x86/entry/common.c:268 [inline] > do_syscall_64+0x40c/0x4f0 arch/x86/entry/common.c:293 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff88821a41bd20 > which belongs to the cache kmalloc-32 of size 32 > The buggy address is located 24 bytes inside of > 32-byte region [ffff88821a41bd20, ffff88821a41bd40) > The buggy address belongs to the page: > page:ffffea00086906c0 count:1 mapcount:0 mapping:ffff88812c3f5800 index:0x0 > flags: 0x57ff00000000200(slab) > raw: 057ff00000000200 dead000000000100 dead000000000200 ffff88812c3f5800 > raw: 0000000000000000 0000000000550055 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff88821a41bc00: 00 00 00 fc fc fc 00 00 00 00 fc fc 00 00 00 00 > ffff88821a41bc80: fc fc 00 00 00 00 fc fc fb fb fb fb fc fc fb fb > > ffff88821a41bd00: fb fb fc fc 00 00 00 fc fc fc fb fb fb fb fc fc > ^ > ffff88821a41bd80: 00 00 00 fc fc fc 00 00 00 fc fc fc fb fb fb fb > ffff88821a41be00: fc fc fb fb fb fb fc fc fb fb fb fb fc fc 00 00 > ================================================================== > > > --- > 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 #syz dup: KASAN: slab-out-of-bounds Read in dlfb_usb_probe
