On Wed, Jun 14, 2017 at 11:20 AM, Stefan Hajnoczi <stefa...@gmail.com> wrote:
> On Tue, Jun 13, 2017 at 12:35:21PM +0200, Gioh Kim wrote:
>> I'd like to report one use-after-free problem which is found by
>> AddressSanitizer.
>> My company provides virtualization server with Qemu-2.7.
>
> I have tried the following but was unable to reproduce a segfault.
> Please reproduce this issue with qemu.git/master and post the steps:
I'm sorry that I wrote ambiguously.
The problem was only by Qemu-2.7 that is qemu.git/stable-2.7 branch.
>
> $ qemu -M accel=kvm -cpu host -m 1G \
> -drive if=none,id=drive0,file=test.img,format=raw \
> -device virtio-blk-pci,drive=drive0,id=virtio-blk-pci0 \
> -drive
> if=none,id=drive1,file.driver=null-co,file.read-zeroes=on,file.latency-ns=5000000000,format=raw
> \
> -device virtio-blk-pci,drive=drive1,id=virtio-blk-pci1 \
> -d trace:virtio_blk_\*
>
I executed qemu with following command.
~/work/tools/qemu/x86_64-softmmu/qemu-system-x86_64 -M accel=kvm -cpu
host -m 1024 -name pb-pserver \
-monitor telnet:0.0.0.0:9400,server,nowait -rtc base=utc \
-vnc 0.0.0.0:0 \
-drive if=none,id=drive0,file=./debian8.2-pserver.img,format=raw \
-device virtio-blk-pci,drive=drive0,id=virtio-blk-pci0 \
-d trace:virtio_blk_\*
And I reproduced the problem with following sequence.
1. on Qemu-monitor
(qemu) drive_add 0
if=none,id=drive1,file.driver=null-co,file.read-zeroes=on,file.latency-ns=5000000000,format=raw
OK
(qemu) device_add virtio-blk-pci,drive=drive1,id=virtio-blk-pci1
2. on Guest OS
# cat test.fio
[global]
ioengine=libaio
direct=1
time_based=1
bssplit=512/20:1k/16:2k/9:4k/12:8k/19:16k/10:32k/8:64k/4
iodepth=128
numjobs=8
[job]
rw=randrw
filename=/dev/vdb
runtime=300
# fio test.fio
3. on Qemu-monitor (just after running fio)
(qemu) device_del virtio-blk-pci1
(qemu) system_reset
(qemu) Connection closed by foreign host. ===> qemu crash
Following is the result of Qemu tracing.
16589@1497450077.404638:virtio_blk_handle_read req 0x611000295d00
sector 166143 nsectors 2
16589@1497450077.404644:virtio_blk_handle_write req 0x611000295bc0
sector 982238 nsectors 64
16589@1497450077.404743:virtio_blk_handle_read req 0x611000295a80
sector 143935 nsectors 8
16589@1497450077.404790:virtio_blk_handle_read req 0x611000295940
sector 1296105 nsectors 16
16589@1497450077.404795:virtio_blk_handle_read req 0x611000295800
sector 1901728 nsectors 16
16589@1497450077.404800:virtio_blk_handle_write req 0x6110002956c0
sector 1420489 nsectors 32
16589@1497450077.404930:virtio_blk_handle_read req 0x611000295580
sector 1422639 nsectors 1
16589@1497450077.404978:virtio_blk_handle_write req 0x611000295440
sector 841715 nsectors 2
16589@1497450077.405026:virtio_blk_handle_read req 0x611000295300
sector 1336979 nsectors 4
16589@1497450077.405075:virtio_blk_handle_read req 0x6110002951c0
sector 1374935 nsectors 16
16589@1497450077.405080:virtio_blk_handle_read req 0x611000295080
sector 826570 nsectors 4
16589@1497450077.405087:virtio_blk_handle_write req 0x611000294f40
sector 1999130 nsectors 16
16589@1497450077.405219:virtio_blk_handle_write req 0x611000294e00
sector 1978172 nsectors 32
16589@1497450077.405224:virtio_blk_handle_read req 0x611000294cc0
sector 1175666 nsectors 1
16589@1497450077.405309:virtio_blk_handle_write req 0x611000294b80
sector 1021650 nsectors 32
16589@1497450077.405357:virtio_blk_handle_write req 0x611000294a40
sector 1723841 nsectors 2
16589@1497450077.405362:virtio_blk_handle_write req 0x611000294900
sector 350119 nsectors 1
16589@1497450077.405367:virtio_blk_handle_read req 0x6110002947c0
sector 1101456 nsectors 2
16589@1497450077.405499:virtio_blk_handle_read req 0x611000294680
sector 721850 nsectors 2
16589@1497450081.580154:virtio_blk_handle_read req 0x61200004a8c0
sector 13127272 nsectors 32
16589@1497450081.580313:virtio_blk_rw_complete req 0x61200004a8c0 ret 0
16589@1497450081.580319:virtio_blk_req_complete req 0x61200004a8c0 status 0
16589@1497450081.580458:virtio_blk_handle_read req 0x613000052ec0
sector 13127304 nsectors 48
16589@1497450081.580595:virtio_blk_rw_complete req 0x613000052ec0 ret 0
16589@1497450081.580602:virtio_blk_req_complete req 0x613000052ec0 status 0
16589@1497450081.619777:virtio_blk_rw_complete req 0x611000279100 ret 0
16589@1497450081.619796:virtio_blk_req_complete req 0x611000279100 status 0
16589@1497450082.400075:virtio_blk_rw_complete req 0x611000276180 ret 0
16589@1497450082.400094:virtio_blk_req_complete req 0x611000276180 status 0
=================================================================
==16589==ERROR: AddressSanitizer: heap-use-after-free on address
0x7fee77ec982c at pc 0x55fa17e13a95 bp 0x7fee72bb3590 sp
0x7fee72bb3580
READ of size 2 at 0x7fee77ec982c thread T0
#0 0x55fa17e13a94 in virtqueue_fill
/home/gohkim/work/tools/qemu/hw/virtio/virtio.c:284
#1 0x55fa17e13d65 in virtqueue_push
/home/gohkim/work/tools/qemu/hw/virtio/virtio.c:308
#2 0x55fa17d7ac24 in virtio_blk_req_complete
/home/gohkim/work/tools/qemu/hw/block/virtio-blk.c:58
#3 0x55fa17d7b104 in virtio_blk_rw_complete
/home/gohkim/work/tools/qemu/hw/block/virtio-blk.c:121
#4 0x55fa185991d8 in blk_aio_complete block/block-backend.c:923
#5 0x55fa1859974a in blk_aio_read_entry block/block-backend.c:973
#6 0x55fa186dbc87 in coroutine_trampoline util/coroutine-ucontext.c:78
#7 0x7feec21ac5cf (/lib/x86_64-linux-gnu/libc.so.6+0x495cf)
0x7fee77ec982c is located 44 bytes inside of 131072-byte region
[0x7fee77ec9800,0x7fee77ee9800)
freed by thread T0 here:
#0 0x7feec5e5f6aa in __interceptor_free
(/usr/lib/x86_64-linux-gnu/libasan.so.2+0x986aa)
#1 0x55fa17e1bec3 in virtio_cleanup
/home/gohkim/work/tools/qemu/hw/virtio/virtio.c:1678
#2 0x55fa17d804a4 in virtio_blk_device_unrealize
/home/gohkim/work/tools/qemu/hw/block/virtio-blk.c:943
#3 0x55fa17e1d653 in virtio_device_unrealize
/home/gohkim/work/tools/qemu/hw/virtio/virtio.c:1950
#4 0x55fa180cdad6 in device_set_realized hw/core/qdev.c:964
#5 0x55fa184d5b0e in property_set_bool qom/object.c:1853
#6 0x55fa184d2454 in object_property_set qom/object.c:1087
#7 0x55fa184d846e in object_property_set_qobject qom/qom-qobject.c:27
#8 0x55fa184d272f in object_property_set_bool qom/object.c:1156
#9 0x55fa180d52b4 in bus_set_realized hw/core/bus.c:181
#10 0x55fa184d5b0e in property_set_bool qom/object.c:1853
#11 0x55fa184d2454 in object_property_set qom/object.c:1087
#12 0x55fa184d846e in object_property_set_qobject qom/qom-qobject.c:27
#13 0x55fa184d272f in object_property_set_bool qom/object.c:1156
#14 0x55fa180cd9a9 in device_set_realized hw/core/qdev.c:956
#15 0x55fa184d5b0e in property_set_bool qom/object.c:1853
#16 0x55fa184d2454 in object_property_set qom/object.c:1087
#17 0x55fa184d846e in object_property_set_qobject qom/qom-qobject.c:27
#18 0x55fa184d272f in object_property_set_bool qom/object.c:1156
#19 0x55fa180ce73f in device_unparent hw/core/qdev.c:1099
#20 0x55fa184d342a in object_finalize_child_property qom/object.c:1362
#21 0x55fa184cf2e5 in object_property_del_child qom/object.c:422
#22 0x55fa184cf520 in object_unparent qom/object.c:441
#23 0x55fa18036110 in acpi_pcihp_eject_slot hw/acpi/pcihp.c:139
#24 0x55fa18036220 in acpi_pcihp_update_hotplug_bus hw/acpi/pcihp.c:152
#25 0x55fa1803651f in acpi_pcihp_update hw/acpi/pcihp.c:176
#26 0x55fa18036547 in acpi_pcihp_reset hw/acpi/pcihp.c:182
#27 0x55fa18033b2f in piix4_reset hw/acpi/piix4.c:363
#28 0x55fa17fb8ddc in qemu_devices_reset
/home/gohkim/work/tools/qemu/vl.c:1713
#29 0x55fa17e3c273 in pc_machine_reset
/home/gohkim/work/tools/qemu/hw/i386/pc.c:2178
previously allocated by thread T0 here:
#0 0x7feec5e5fb49 in __interceptor_calloc
(/usr/lib/x86_64-linux-gnu/libasan.so.2+0x98b49)
#1 0x7feec372f5d0 in g_malloc0
(/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x4f5d0)
#2 0x55fa17d7ff55 in virtio_blk_device_realize
/home/gohkim/work/tools/qemu/hw/block/virtio-blk.c:910
#3 0x55fa17e1d41f in virtio_device_realize
/home/gohkim/work/tools/qemu/hw/virtio/virtio.c:1927
#4 0x55fa180cd5af in device_set_realized hw/core/qdev.c:918
#5 0x55fa184d5b0e in property_set_bool qom/object.c:1853
#6 0x55fa184d2454 in object_property_set qom/object.c:1087
#7 0x55fa184d846e in object_property_set_qobject qom/qom-qobject.c:27
#8 0x55fa184d272f in object_property_set_bool qom/object.c:1156
#9 0x55fa183c5a7b in virtio_blk_pci_realize hw/virtio/virtio-pci.c:1897
#10 0x55fa183c53fe in virtio_pci_realize hw/virtio/virtio-pci.c:1799
#11 0x55fa182721e4 in pci_qdev_realize hw/pci/pci.c:1966
#12 0x55fa183c56fa in virtio_pci_dc_realize hw/virtio/virtio-pci.c:1852
#13 0x55fa180cd5af in device_set_realized hw/core/qdev.c:918
#14 0x55fa184d5b0e in property_set_bool qom/object.c:1853
#15 0x55fa184d2454 in object_property_set qom/object.c:1087
#16 0x55fa184d846e in object_property_set_qobject qom/qom-qobject.c:27
#17 0x55fa184d272f in object_property_set_bool qom/object.c:1156
#18 0x55fa17f9533d in qdev_device_add
/home/gohkim/work/tools/qemu/qdev-monitor.c:618
#19 0x55fa17f962e2 in qmp_device_add
/home/gohkim/work/tools/qemu/qdev-monitor.c:795
#20 0x55fa17ff29e7 in hmp_device_add /home/gohkim/work/tools/qemu/hmp.c:1600
#21 0x55fa17d0eb75 in handle_hmp_command
/home/gohkim/work/tools/qemu/monitor.c:2957
#22 0x55fa17d13252 in monitor_command_cb
/home/gohkim/work/tools/qemu/monitor.c:4025
#23 0x55fa186d6cd1 in readline_handle_byte util/readline.c:393
#24 0x55fa17d1316f in monitor_read
/home/gohkim/work/tools/qemu/monitor.c:4008
#25 0x55fa17f99836 in qemu_chr_be_write_impl
/home/gohkim/work/tools/qemu/qemu-char.c:387
#26 0x55fa17f99903 in qemu_chr_be_write
/home/gohkim/work/tools/qemu/qemu-char.c:399
#27 0x55fa17fa3c57 in tcp_chr_read
/home/gohkim/work/tools/qemu/qemu-char.c:2933
#28 0x55fa18613bbd in qio_channel_fd_source_dispatch io/channel-watch.c:84
#29 0x7feec3729ea9 in g_main_context_dispatch
(/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x49ea9)
SUMMARY: AddressSanitizer: heap-use-after-free
/home/gohkim/work/tools/qemu/hw/virtio/virtio.c:284 virtqueue_fill
Shadow bytes around the buggy address:
0x0ffe4efd12b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0ffe4efd12c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0ffe4efd12d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0ffe4efd12e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0ffe4efd12f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0ffe4efd1300: fd fd fd fd fd[fd]fd fd fd fd fd fd fd fd fd fd
0x0ffe4efd1310: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x0ffe4efd1320: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x0ffe4efd1330: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x0ffe4efd1340: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
0x0ffe4efd1350: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Heap right redzone: fb
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
==16589==ABORTING
--
Best regards,
Gi-Oh Kim
TEL: 0176 2697 8962
