Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Docker-in-docker (dind) under QEMU emulation #4

Open
7 tasks
tiborvass opened this issue Jun 5, 2019 · 1 comment
Open
7 tasks

Docker-in-docker (dind) under QEMU emulation #4

tiborvass opened this issue Jun 5, 2019 · 1 comment

Comments

@tiborvass
Copy link

tiborvass commented Jun 5, 2019

This issue is to track the ability to run docker in docker under QEMU emulation.

QEMU does not implement all the needed syscalls and some syscalls have incorrect or incomplete implementations. Here is a non-exhaustive list of issues, that were discovered:

  • incorrect signal handling in clone() when flags=0
  • missing pivot_root syscall
  • missing copy_file_range syscall
  • missing keyctl syscall
  • missing memfd_create syscall
  • missing F_GET_SEALS and F_ADD_SEALS for fcntl syscall
  • incorrect handling when running execve of /proc/self/exe (used by Go reexec packages)

Tonis and I took a stab at it and it resulted in 3 types of patches:

  1. Ready-to-PR
  • Fix signal handling in clone() when flags=0: tiborvass@dd245fa
    (should be upstreamed)
  • Implement pivot_root syscall: tiborvass@671e0b3
    (can be upstreamed)
  • exec /proc/self/exe with binfmt assumptions (for reexec):
    tiborvass@cd60352
    This assumes QEMU is setup with binfmt with the preserve (P) option. More difficult to upstream.
  1. Stop-gap patches
  • copy_file_range and keyctl YOLO implementations:
    tiborvass@0508cf0
    This works because downstream code has fallbacks that work with these patches. These syscalls need proper implementations.
  • qemu detection hack:
    tiborvass@a3b4db2
    This can be used by downstream code to disable features that don't work yet.
  1. Fix attempts that were not needed/exercised in the end

Ping @adamparco @justincormack

@adamparco
Copy link
Collaborator

CC @jasonrandrews

tuonga pushed a commit that referenced this issue Jun 6, 2019
Even for block nodes with bs->drv == NULL, we can't just ignore a
bdrv_set_aio_context() call. Leaving the node in its old context can
mean that it's still in an iothread context in bdrv_close_all() during
shutdown, resulting in an attempted unlock of the AioContext lock which
we don't hold.

This is an example stack trace of a related crash:

 #0  0x00007ffff59da57f in raise () at /lib64/libc.so.6
 #1  0x00007ffff59c4895 in abort () at /lib64/libc.so.6
 #2  0x0000555555b97b1e in error_exit (err=<optimized out>, msg=msg@entry=0x555555d386d0 <__func__.19059> "qemu_mutex_unlock_impl") at util/qemu-thread-posix.c:36
 #3  0x0000555555b97f7f in qemu_mutex_unlock_impl (mutex=mutex@entry=0x5555568002f0, file=file@entry=0x555555d378df "util/async.c", line=line@entry=507) at util/qemu-thread-posix.c:97
 #4  0x0000555555b92f55 in aio_context_release (ctx=ctx@entry=0x555556800290) at util/async.c:507
 #5  0x0000555555b05cf8 in bdrv_prwv_co (child=child@entry=0x7fffc80012f0, offset=offset@entry=131072, qiov=qiov@entry=0x7fffffffd4f0, is_write=is_write@entry=true, flags=flags@entry=0)
         at block/io.c:833
 #6  0x0000555555b060a9 in bdrv_pwritev (qiov=0x7fffffffd4f0, offset=131072, child=0x7fffc80012f0) at block/io.c:990
 #7  0x0000555555b060a9 in bdrv_pwrite (child=0x7fffc80012f0, offset=131072, buf=<optimized out>, bytes=<optimized out>) at block/io.c:990
 #8  0x0000555555ae172b in qcow2_cache_entry_flush (bs=bs@entry=0x555556810680, c=c@entry=0x5555568cc740, i=i@entry=0) at block/qcow2-cache.c:51
 #9  0x0000555555ae18dd in qcow2_cache_write (bs=bs@entry=0x555556810680, c=0x5555568cc740) at block/qcow2-cache.c:248
 #10 0x0000555555ae15de in qcow2_cache_flush (bs=0x555556810680, c=<optimized out>) at block/qcow2-cache.c:259
 #11 0x0000555555ae16b1 in qcow2_cache_flush_dependency (c=0x5555568a1700, c=0x5555568a1700, bs=0x555556810680) at block/qcow2-cache.c:194
 #12 0x0000555555ae16b1 in qcow2_cache_entry_flush (bs=bs@entry=0x555556810680, c=c@entry=0x5555568a1700, i=i@entry=0) at block/qcow2-cache.c:194
 #13 0x0000555555ae18dd in qcow2_cache_write (bs=bs@entry=0x555556810680, c=0x5555568a1700) at block/qcow2-cache.c:248
 #14 0x0000555555ae15de in qcow2_cache_flush (bs=bs@entry=0x555556810680, c=<optimized out>) at block/qcow2-cache.c:259
 #15 0x0000555555ad242c in qcow2_inactivate (bs=bs@entry=0x555556810680) at block/qcow2.c:2124
 #16 0x0000555555ad2590 in qcow2_close (bs=0x555556810680) at block/qcow2.c:2153
 #17 0x0000555555ab0c62 in bdrv_close (bs=0x555556810680) at block.c:3358
 #18 0x0000555555ab0c62 in bdrv_delete (bs=0x555556810680) at block.c:3542
 #19 0x0000555555ab0c62 in bdrv_unref (bs=0x555556810680) at block.c:4598
 qemu#20 0x0000555555af4d72 in blk_remove_bs (blk=blk@entry=0x5555568103d0) at block/block-backend.c:785
 qemu#21 0x0000555555af4dbb in blk_remove_all_bs () at block/block-backend.c:483
 qemu#22 0x0000555555aae02f in bdrv_close_all () at block.c:3412
 qemu#23 0x00005555557f9796 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4776

The reproducer I used is a qcow2 image on gluster volume, where the
virtual disk size (4 GB) is larger than the gluster volume size (64M),
so we can easily trigger an ENOSPC. This backend is assigned to a
virtio-blk device using an iothread, and then from the guest a
'dd if=/dev/zero of=/dev/vda bs=1G count=1' causes the VM to stop
because of an I/O error. qemu_gluster_co_flush_to_disk() sets
bs->drv = NULL on error, so when virtio-blk stops the dataplane, the
block nodes stay in the iothread AioContext. A 'quit' monitor command
issued from this paused state crashes the process.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1631227
Cc: [email protected]
Signed-off-by: Kevin Wolf <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Reviewed-by: Max Reitz <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>
tuonga pushed a commit that referenced this issue Jun 6, 2019
It fixes heap-use-after-free which was found by clang's ASAN.

Control flow of this use-after-free:
main_thread:
    * Got SIGTERM and completes main loop
    * Calls migration_shutdown
      - migrate_fd_cancel (so, migration_thread begins to complete)
      - object_unref(OBJECT(current_migration));

migration_thread:
    * migration_iteration_finish -> schedule cleanup bh
    * object_unref(OBJECT(s)); (Now, current_migration is freed)
    * exits

main_thread:
    * Calls vm_shutdown -> drain bdrvs -> main loop
      -> cleanup_bh -> use after free

If you want to reproduce, these couple of sleeps will help:
vl.c:4613:
     migration_shutdown();
+    sleep(2);
migration.c:3269:
+    sleep(1);
     trace_migration_thread_after_loop();
     migration_iteration_finish(s);

Original output:
qemu-system-x86_64: terminating on signal 15 from pid 31980 (<unknown process>)
=================================================================
==31958==ERROR: AddressSanitizer: heap-use-after-free on address 0x61900001d210
  at pc 0x555558a535ca bp 0x7fffffffb190 sp 0x7fffffffb188
READ of size 8 at 0x61900001d210 thread T0 (qemu-vm-0)
    #0 0x555558a535c9 in migrate_fd_cleanup migration/migration.c:1502:23
    #1 0x5555594fde0a in aio_bh_call util/async.c:90:5
    #2 0x5555594fe522 in aio_bh_poll util/async.c:118:13
    #3 0x555559524783 in aio_poll util/aio-posix.c:725:17
    #4 0x555559504fb3 in aio_wait_bh_oneshot util/aio-wait.c:71:5
    #5 0x5555573bddf6 in virtio_blk_data_plane_stop
      hw/block/dataplane/virtio-blk.c:282:5
    #6 0x5555589d5c09 in virtio_bus_stop_ioeventfd hw/virtio/virtio-bus.c:246:9
    #7 0x5555589e9917 in virtio_pci_stop_ioeventfd hw/virtio/virtio-pci.c:287:5
    #8 0x5555589e22bf in virtio_pci_vmstate_change hw/virtio/virtio-pci.c:1072:9
    #9 0x555557628931 in virtio_vmstate_change hw/virtio/virtio.c:2257:9
    #10 0x555557c36713 in vm_state_notify vl.c:1605:9
    #11 0x55555716ef53 in do_vm_stop cpus.c:1074:9
    #12 0x55555716eeff in vm_shutdown cpus.c:1092:12
    #13 0x555557c4283e in main vl.c:4617:5
    #14 0x7fffdfdb482f in __libc_start_main
      (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #15 0x555556ecb118 in _start (x86_64-softmmu/qemu-system-x86_64+0x1977118)

0x61900001d210 is located 144 bytes inside of 952-byte region
  [0x61900001d180,0x61900001d538)
freed by thread T6 (live_migration) here:
    #0 0x555556f76782 in __interceptor_free
      /tmp/final/llvm.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:124:3
    #1 0x555558d5fa94 in object_finalize qom/object.c:618:9
    #2 0x555558d57651 in object_unref qom/object.c:1068:9
    #3 0x555558a55588 in migration_thread migration/migration.c:3272:5
    #4 0x5555595393f2 in qemu_thread_start util/qemu-thread-posix.c:502:9
    #5 0x7fffe057f6b9 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76b9)

previously allocated by thread T0 (qemu-vm-0) here:
    #0 0x555556f76b03 in __interceptor_malloc
      /tmp/final/llvm.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:146:3
    #1 0x7ffff6ee37b8 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x4f7b8)
    #2 0x555558d58031 in object_new qom/object.c:640:12
    #3 0x555558a31f21 in migration_object_init migration/migration.c:139:25
    #4 0x555557c41398 in main vl.c:4320:5
    #5 0x7fffdfdb482f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)

Thread T6 (live_migration) created by T0 (qemu-vm-0) here:
    #0 0x555556f5f0dd in pthread_create
      /tmp/final/llvm.src/projects/compiler-rt/lib/asan/asan_interceptors.cc:210:3
    #1 0x555559538cf9 in qemu_thread_create util/qemu-thread-posix.c:539:11
    #2 0x555558a53304 in migrate_fd_connect migration/migration.c:3332:5
    #3 0x555558a72bd8 in migration_channel_connect migration/channel.c:92:5
    #4 0x555558a6ef87 in exec_start_outgoing_migration migration/exec.c:42:5
    #5 0x555558a4f3c2 in qmp_migrate migration/migration.c:1922:9
    #6 0x555558bb4f6a in qmp_marshal_migrate qapi/qapi-commands-migration.c:607:5
    #7 0x555559363738 in do_qmp_dispatch qapi/qmp-dispatch.c:131:5
    #8 0x555559362a15 in qmp_dispatch qapi/qmp-dispatch.c:174:11
    #9 0x5555571bac15 in monitor_qmp_dispatch monitor.c:4124:11
    #10 0x55555719a22d in monitor_qmp_bh_dispatcher monitor.c:4207:9
    #11 0x5555594fde0a in aio_bh_call util/async.c:90:5
    #12 0x5555594fe522 in aio_bh_poll util/async.c:118:13
    #13 0x5555595201e0 in aio_dispatch util/aio-posix.c:460:5
    #14 0x555559503553 in aio_ctx_dispatch util/async.c:261:5
    #15 0x7ffff6ede196 in g_main_context_dispatch
      (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x4a196)

SUMMARY: AddressSanitizer: heap-use-after-free migration/migration.c:1502:23
  in migrate_fd_cleanup
Shadow bytes around the buggy address:
  0x0c327fffb9f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c327fffba00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c327fffba10: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c327fffba20: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c327fffba30: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
=>0x0c327fffba40: fd fd[fd]fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c327fffba50: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c327fffba60: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c327fffba70: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c327fffba80: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x0c327fffba90: 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
  Freed heap region: fd
  Stack left redzone: f1
  Stack mid redzone: f2
  Stack right redzone: f3
  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
  Left alloca redzone: ca
  Right alloca redzone: cb
  Shadow gap: cc
==31958==ABORTING

Signed-off-by: Yury Kotov <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Dr. David Alan Gilbert <[email protected]>
Signed-off-by: Dr. David Alan Gilbert <[email protected]>
  Fixed up comment formatting
tuonga pushed a commit that referenced this issue Jun 6, 2019
When writing a new board, adding device which uses other devices
(container) or simply refactoring, one can discover the hard way
his machine misses some devices. In the case of containers, the
error is not obvious:

  $ qemu-system-microblaze -M xlnx-zynqmp-pmu
  **
  ERROR:/source/qemu/qom/object.c:454:object_initialize_with_type: assertion failed: (type != NULL)
  Aborted (core dumped)

And we have to look at the coredump to figure the error:

  (gdb) bt
  #1  0x00007f84773cf895 in abort () at /lib64/libc.so.6
  #2  0x00007f847961fb53 in  () at /lib64/libglib-2.0.so.0
  #3  0x00007f847967a4de in g_assertion_message_expr () at /lib64/libglib-2.0.so.0
  #4  0x000055c4bcac6c11 in object_initialize_with_type (data=data@entry=0x55c4bdf239e0, size=size@entry=2464, type=<optimized out>) at /source/qemu/qom/object.c:454
  #5  0x000055c4bcac6e6d in object_initialize (data=data@entry=0x55c4bdf239e0, size=size@entry=2464, typename=typename@entry=0x55c4bcc7c643 "xlnx.zynqmp_ipi") at /source/qemu/qom/object.c:474
  #6  0x000055c4bc9ea474 in xlnx_zynqmp_pmu_init (machine=0x55c4bdd46000) at /source/qemu/hw/microblaze/xlnx-zynqmp-pmu.c:176
  #7  0x000055c4bca3b6cb in machine_run_board_init (machine=0x55c4bdd46000) at /source/qemu/hw/core/machine.c:1030
  #8  0x000055c4bc95f6d2 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /source/qemu/vl.c:4479

Since the caller knows the type name requested, we can simply display it
to ease development.

With this patch applied we get:

  $ qemu-system-microblaze -M xlnx-zynqmp-pmu
  qemu-system-microblaze: missing object type 'xlnx.zynqmp_ipi'
  Aborted (core dumped)

Since the assert(type) check in object_initialize_with_type() is
now impossible, remove it.

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>
Reviewed-by: Daniel P. Berrangé <[email protected]>
Signed-off-by: Eduardo Habkost <[email protected]>
tuonga pushed a commit that referenced this issue Jul 25, 2019
When emulating irqchip in qemu, such as following command:

x86_64-softmmu/qemu-system-x86_64 -m 1024 -smp 4 -hda /home/test/test.img
-machine kernel-irqchip=off --enable-kvm -vnc :0 -device edu -monitor stdio

We will get a crash with following asan output:

(qemu) /home/test/qemu5/qemu/hw/intc/ioapic.c:266:27: runtime error: index 35 out of bounds for type 'int [24]'
=================================================================
==113504==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61b000003114 at pc 0x5579e3c7a80f bp 0x7fd004bf8c10 sp 0x7fd004bf8c00
WRITE of size 4 at 0x61b000003114 thread T4
    #0 0x5579e3c7a80e in ioapic_eoi_broadcast /home/test/qemu5/qemu/hw/intc/ioapic.c:266
    #1 0x5579e3c6f480 in apic_eoi /home/test/qemu5/qemu/hw/intc/apic.c:428
    #2 0x5579e3c720a7 in apic_mem_write /home/test/qemu5/qemu/hw/intc/apic.c:802
    #3 0x5579e3b1e31a in memory_region_write_accessor /home/test/qemu5/qemu/memory.c:503
    #4 0x5579e3b1e6a2 in access_with_adjusted_size /home/test/qemu5/qemu/memory.c:569
    #5 0x5579e3b28d77 in memory_region_dispatch_write /home/test/qemu5/qemu/memory.c:1497
    #6 0x5579e3a1b36b in flatview_write_continue /home/test/qemu5/qemu/exec.c:3323
    #7 0x5579e3a1b633 in flatview_write /home/test/qemu5/qemu/exec.c:3362
    #8 0x5579e3a1bcb1 in address_space_write /home/test/qemu5/qemu/exec.c:3452
    #9 0x5579e3a1bd03 in address_space_rw /home/test/qemu5/qemu/exec.c:3463
    #10 0x5579e3b8b979 in kvm_cpu_exec /home/test/qemu5/qemu/accel/kvm/kvm-all.c:2045
    #11 0x5579e3ae4499 in qemu_kvm_cpu_thread_fn /home/test/qemu5/qemu/cpus.c:1287
    #12 0x5579e4cbdb9f in qemu_thread_start util/qemu-thread-posix.c:502
    #13 0x7fd0146376da in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76da)
    #14 0x7fd01436088e in __clone (/lib/x86_64-linux-gnu/libc.so.6+0x12188e

This is because in ioapic_eoi_broadcast function, we uses 'vector' to
index the 's->irq_eoi'. To fix this, we should uses the irq number.

Signed-off-by: Li Qiang <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Message-Id: <[email protected]>
tuonga pushed a commit that referenced this issue Jul 25, 2019
The test aarch64 kernel is in an array defined with
 unsigned char aarch64_kernel[] = { [...] }

which means it could be any size; currently it's quite small.
However we write it to a file using init_bootfile(), which
writes exactly 512 bytes to the file. This will break if
we ever end up with a kernel larger than that, and will
read garbage off the end of the array in the current setup
where the kernel is smaller.

Make init_bootfile() take an argument giving the length of
the data to write. This allows us to use it for all architectures
(previously s390 had a special-purpose init_bootfile_s390x
which hardcoded the file to write so it could write the
correct length). We assert that the x86 bootfile really is
exactly 512 bytes as it should be (and as we were previously
just assuming it was).

This was detected by the clang-7 asan:
==15607==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55a796f51d20 at pc 0x55a796b89c2f bp 0x7ffc58e89160 sp 0x7ffc58e88908
READ of size 512 at 0x55a796f51d20 thread T0
    #0 0x55a796b89c2e in fwrite (/home/petmay01/linaro/qemu-from-laptop/qemu/build/sanitizers/tests/migration-test+0xb0c2e)
    #1 0x55a796c46492 in init_bootfile /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:99:5
    #2 0x55a796c46492 in test_migrate_start /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:593
    #3 0x55a796c44101 in test_baddest /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:854:9
    #4 0x7f906ffd3cc9  (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72cc9)
    #5 0x7f906ffd3bfa  (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72bfa)
    #6 0x7f906ffd3bfa  (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72bfa)
    #7 0x7f906ffd3ea1 in g_test_run_suite (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72ea1)
    #8 0x7f906ffd3ec0 in g_test_run (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72ec0)
    #9 0x55a796c43707 in main /home/petmay01/linaro/qemu-from-laptop/qemu/tests/migration-test.c:1187:11
    #10 0x7f906e9abb96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310
    #11 0x55a796b6c2d9 in _start (/home/petmay01/linaro/qemu-from-laptop/qemu/build/sanitizers/tests/migration-test+0x932d9)

Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Laurent Vivier <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-id: [email protected]
tuonga pushed a commit that referenced this issue Jul 25, 2019
Reading the RX_DATA register when the RX_FIFO is empty triggers
an abort. This can be easily reproduced:

  $ qemu-system-arm -M emcraft-sf2 -monitor stdio -S
  QEMU 4.0.50 monitor - type 'help' for more information
  (qemu) x 0x40001010
  Aborted (core dumped)

  (gdb) bt
  #1  0x00007f035874f895 in abort () at /lib64/libc.so.6
  #2  0x00005628686591ff in fifo8_pop (fifo=0x56286a9a4c68) at util/fifo8.c:66
  #3  0x00005628683e0b8e in fifo32_pop (fifo=0x56286a9a4c68) at include/qemu/fifo32.h:137
  #4  0x00005628683e0efb in spi_read (opaque=0x56286a9a4850, addr=4, size=4) at hw/ssi/mss-spi.c:168
  #5  0x0000562867f96801 in memory_region_read_accessor (mr=0x56286a9a4b60, addr=16, value=0x7ffeecb0c5c8, size=4, shift=0, mask=4294967295, attrs=...) at memory.c:439
  #6  0x0000562867f96cdb in access_with_adjusted_size (addr=16, value=0x7ffeecb0c5c8, size=4, access_size_min=1, access_size_max=4, access_fn=0x562867f967c3 <memory_region_read_accessor>, mr=0x56286a9a4b60, attrs=...) at memory.c:569
  #7  0x0000562867f99940 in memory_region_dispatch_read1 (mr=0x56286a9a4b60, addr=16, pval=0x7ffeecb0c5c8, size=4, attrs=...) at memory.c:1420
  #8  0x0000562867f99a08 in memory_region_dispatch_read (mr=0x56286a9a4b60, addr=16, pval=0x7ffeecb0c5c8, size=4, attrs=...) at memory.c:1447
  #9  0x0000562867f38721 in flatview_read_continue (fv=0x56286aec6360, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4, addr1=16, l=4, mr=0x56286a9a4b60) at exec.c:3385
  #10 0x0000562867f38874 in flatview_read (fv=0x56286aec6360, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4) at exec.c:3423
  #11 0x0000562867f388ea in address_space_read_full (as=0x56286aa3e890, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4) at exec.c:3436
  #12 0x0000562867f389c5 in address_space_rw (as=0x56286aa3e890, addr=1073745936, attrs=..., buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4, is_write=false) at exec.c:3466
  #13 0x0000562867f3bdd7 in cpu_memory_rw_debug (cpu=0x56286aa19d00, addr=1073745936, buf=0x7ffeecb0c7c0 "\340ǰ\354\376\177", len=4, is_write=0) at exec.c:3976
  #14 0x000056286811ed51 in memory_dump (mon=0x56286a8c32d0, count=1, format=120, wsize=4, addr=1073745936, is_physical=0) at monitor/misc.c:730
  #15 0x000056286811eff1 in hmp_memory_dump (mon=0x56286a8c32d0, qdict=0x56286b15c400) at monitor/misc.c:785
  #16 0x00005628684740ee in handle_hmp_command (mon=0x56286a8c32d0, cmdline=0x56286a8caeb2 "0x40001010") at monitor/hmp.c:1082

From the datasheet "Actel SmartFusion Microcontroller Subsystem
User's Guide" Rev.1, Table 13-3 "SPI Register Summary", this
register has a reset value of 0.

Check the FIFO is not empty before accessing it, else log an
error message.

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Message-id: [email protected]
Signed-off-by: Peter Maydell <[email protected]>
tuonga pushed a commit that referenced this issue Jul 25, 2019
In the previous commit we fixed a crash when the guest read a
register that pop from an empty FIFO.
By auditing the repository, we found another similar use with
an easy way to reproduce:

  $ qemu-system-aarch64 -M xlnx-zcu102 -monitor stdio -S
  QEMU 4.0.50 monitor - type 'help' for more information
  (qemu) xp/b 0xfd4a0134
  Aborted (core dumped)

  (gdb) bt
  #0  0x00007f6936dea57f in raise () at /lib64/libc.so.6
  #1  0x00007f6936dd4895 in abort () at /lib64/libc.so.6
  #2  0x0000561ad32975ec in xlnx_dp_aux_pop_rx_fifo (s=0x7f692babee70) at hw/display/xlnx_dp.c:431
  #3  0x0000561ad3297dc0 in xlnx_dp_read (opaque=0x7f692babee70, offset=77, size=4) at hw/display/xlnx_dp.c:667
  #4  0x0000561ad321b896 in memory_region_read_accessor (mr=0x7f692babf620, addr=308, value=0x7ffe05c1db88, size=4, shift=0, mask=4294967295, attrs=...) at memory.c:439
  #5  0x0000561ad321bd70 in access_with_adjusted_size (addr=308, value=0x7ffe05c1db88, size=1, access_size_min=4, access_size_max=4, access_fn=0x561ad321b858 <memory_region_read_accessor>, mr=0x7f692babf620, attrs=...) at memory.c:569
  #6  0x0000561ad321e9d5 in memory_region_dispatch_read1 (mr=0x7f692babf620, addr=308, pval=0x7ffe05c1db88, size=1, attrs=...) at memory.c:1420
  #7  0x0000561ad321ea9d in memory_region_dispatch_read (mr=0x7f692babf620, addr=308, pval=0x7ffe05c1db88, size=1, attrs=...) at memory.c:1447
  #8  0x0000561ad31bd742 in flatview_read_continue (fv=0x561ad69c04f0, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1, addr1=308, l=1, mr=0x7f692babf620) at exec.c:3385
  #9  0x0000561ad31bd895 in flatview_read (fv=0x561ad69c04f0, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1) at exec.c:3423
  #10 0x0000561ad31bd90b in address_space_read_full (as=0x561ad5bb3020, addr=4249485620, attrs=..., buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", len=1) at exec.c:3436
  #11 0x0000561ad33b1c42 in address_space_read (len=1, buf=0x7ffe05c1dcf0 "\020\335\301\005\376\177", attrs=..., addr=4249485620, as=0x561ad5bb3020) at include/exec/memory.h:2131
  #12 0x0000561ad33b1c42 in memory_dump (mon=0x561ad59c4530, count=1, format=120, wsize=1, addr=4249485620, is_physical=1) at monitor/misc.c:723
  #13 0x0000561ad33b1fc1 in hmp_physical_memory_dump (mon=0x561ad59c4530, qdict=0x561ad6c6fd00) at monitor/misc.c:795
  #14 0x0000561ad37b4a9f in handle_hmp_command (mon=0x561ad59c4530, cmdline=0x561ad59d0f22 "/b 0x00000000fd4a0134") at monitor/hmp.c:1082

Fix by checking the FIFO is not empty before popping from it.

The datasheet is not clear about the reset value of this register,
we choose to return '0'.

Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Message-id: [email protected]
Signed-off-by: Peter Maydell <[email protected]>
tuonga pushed a commit that referenced this issue Jul 25, 2019
When creating the admin queue in nvme_init() the variable that
holds the number of queues created is modified before actual
queue creation. This is a problem because if creating the queue
fails then the variable is left in inconsistent state. This was
actually observed when I tried to hotplug a nvme disk. The
control got to nvme_file_open() which called nvme_init() which
failed and thus nvme_close() was called which in turn called
nvme_free_queue_pair() with queue being NULL. This lead to an
instant crash:

  #0  0x000055d9507ec211 in nvme_free_queue_pair (bs=0x55d952ddb880, q=0x0) at block/nvme.c:164
  #1  0x000055d9507ee180 in nvme_close (bs=0x55d952ddb880) at block/nvme.c:729
  #2  0x000055d9507ee3d5 in nvme_file_open (bs=0x55d952ddb880, options=0x55d952bb1410, flags=147456, errp=0x7ffd8e19e200) at block/nvme.c:781
  #3  0x000055d9507629f3 in bdrv_open_driver (bs=0x55d952ddb880, drv=0x55d95109c1e0 <bdrv_nvme>, node_name=0x0, options=0x55d952bb1410, open_flags=147456, errp=0x7ffd8e19e310) at block.c:1291
  #4  0x000055d9507633d6 in bdrv_open_common (bs=0x55d952ddb880, file=0x0, options=0x55d952bb1410, errp=0x7ffd8e19e310) at block.c:1551
  #5  0x000055d950766881 in bdrv_open_inherit (filename=0x0, reference=0x0, options=0x55d952bb1410, flags=32768, parent=0x55d9538ce420, child_role=0x55d950eaade0 <child_file>, errp=0x7ffd8e19e510) at block.c:3063
  #6  0x000055d950765ae4 in bdrv_open_child_bs (filename=0x0, options=0x55d9541cdff0, bdref_key=0x55d950af33aa "file", parent=0x55d9538ce420, child_role=0x55d950eaade0 <child_file>, allow_none=true, errp=0x7ffd8e19e510) at block.c:2712
  #7  0x000055d950766633 in bdrv_open_inherit (filename=0x0, reference=0x0, options=0x55d9541cdff0, flags=0, parent=0x0, child_role=0x0, errp=0x7ffd8e19e908) at block.c:3011
  #8  0x000055d950766dba in bdrv_open (filename=0x0, reference=0x0, options=0x55d953d00390, flags=0, errp=0x7ffd8e19e908) at block.c:3156
  #9  0x000055d9507cb635 in blk_new_open (filename=0x0, reference=0x0, options=0x55d953d00390, flags=0, errp=0x7ffd8e19e908) at block/block-backend.c:389
  #10 0x000055d950465ec5 in blockdev_init (file=0x0, bs_opts=0x55d953d00390, errp=0x7ffd8e19e908) at blockdev.c:602

Signed-off-by: Michal Privoznik <[email protected]>
Message-id: 927aae40b617ba7d4b6c7ffe74e6d7a2595f8e86.1562770546.git.mprivozn@redhat.com
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Tested-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Maxim Levitsky <[email protected]>
Signed-off-by: Max Reitz <[email protected]>
tuonga pushed a commit that referenced this issue Jul 25, 2019
commit a6f230c move blockbackend back to main AioContext on unplug. It set the AioContext of
SCSIDevice to the main AioContex, but s->ctx is still the iothread AioContex(if the scsi controller
is configure with iothread). So if there are having in-flight requests during unplug, a failing assertion
happend. The bt is below:
(gdb) bt
#0  0x0000ffff86aacbd0 in raise () from /lib64/libc.so.6
#1  0x0000ffff86aadf7c in abort () from /lib64/libc.so.6
#2  0x0000ffff86aa6124 in __assert_fail_base () from /lib64/libc.so.6
#3  0x0000ffff86aa61a4 in __assert_fail () from /lib64/libc.so.6
#4  0x0000000000529118 in virtio_scsi_ctx_check (d=<optimized out>, s=<optimized out>, s=<optimized out>) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:246
#5  0x0000000000529ec4 in virtio_scsi_handle_cmd_req_prepare (s=0x2779ec00, req=0xffff740397d0) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:559
#6  0x000000000052a228 in virtio_scsi_handle_cmd_vq (s=0x2779ec00, vq=0xffff7c6d7110) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:603
#7  0x000000000052afa8 in virtio_scsi_data_plane_handle_cmd (vdev=<optimized out>, vq=0xffff7c6d7110) at /home/qemu-4.0.0/hw/scsi/virtio-scsi-dataplane.c:59
#8  0x000000000054d94c in virtio_queue_host_notifier_aio_poll (opaque=<optimized out>) at /home/qemu-4.0.0/hw/virtio/virtio.c:2452

assert(blk_get_aio_context(d->conf.blk) == s->ctx) failed.

To avoid assertion failed,  moving the "if" after qdev_simple_device_unplug_cb.

In addition, to avoid another qemu crash below, add aio_disable_external before
qdev_simple_device_unplug_cb, which disable the further processing of external clients
when doing qdev_simple_device_unplug_cb.
(gdb) bt
#0  scsi_req_unref (req=0xffff6802c6f0) at hw/scsi/scsi-bus.c:1283
#1  0x00000000005294a4 in virtio_scsi_handle_cmd_req_submit (req=<optimized out>,
    s=<optimized out>) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:589
#2  0x000000000052a2a8 in virtio_scsi_handle_cmd_vq (s=s@entry=0x9c90e90,
    vq=vq@entry=0xffff7c05f110) at /home/qemu-4.0.0/hw/scsi/virtio-scsi.c:625
#3  0x000000000052afd8 in virtio_scsi_data_plane_handle_cmd (vdev=<optimized out>,
    vq=0xffff7c05f110) at /home/qemu-4.0.0/hw/scsi/virtio-scsi-dataplane.c:60
#4  0x000000000054d97c in virtio_queue_host_notifier_aio_poll (opaque=<optimized out>)
    at /home/qemu-4.0.0/hw/virtio/virtio.c:2447
#5  0x00000000009b204c in run_poll_handlers_once (ctx=ctx@entry=0x6efea40,
    timeout=timeout@entry=0xffff7d7f7308) at util/aio-posix.c:521
#6  0x00000000009b2b64 in run_poll_handlers (ctx=ctx@entry=0x6efea40,
    max_ns=max_ns@entry=4000, timeout=timeout@entry=0xffff7d7f7308) at util/aio-posix.c:559
#7  0x00000000009b2ca0 in try_poll_mode (ctx=ctx@entry=0x6efea40, timeout=0xffff7d7f7308,
    timeout@entry=0xffff7d7f7348) at util/aio-posix.c:594
#8  0x00000000009b31b8 in aio_poll (ctx=0x6efea40, blocking=blocking@entry=true)
    at util/aio-posix.c:636
#9  0x00000000006973cc in iothread_run (opaque=0x6ebd800) at iothread.c:75
#10 0x00000000009b592c in qemu_thread_start (args=0x6efef60) at util/qemu-thread-posix.c:502
#11 0x0000ffff8057f8bc in start_thread () from /lib64/libpthread.so.0
#12 0x0000ffff804e5f8c in thread_start () from /lib64/libc.so.6
(gdb) p bus
$1 = (SCSIBus *) 0x0

Signed-off-by: Zhengui li <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
tuonga pushed a commit that referenced this issue Aug 26, 2019
If interface_count is NO_INTERFACE_INFO, let's not access the arrays
out-of-bounds.

==994==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x625000243930 at pc 0x5642068086a8 bp 0x7f0b6f9ffa50 sp 0x7f0b6f9ffa40
READ of size 1 at 0x625000243930 thread T0
    #0 0x5642068086a7 in usbredir_check_bulk_receiving /home/elmarco/src/qemu/hw/usb/redirect.c:1503
    #1 0x56420681301c in usbredir_post_load /home/elmarco/src/qemu/hw/usb/redirect.c:2154
    #2 0x5642068a56c2 in vmstate_load_state /home/elmarco/src/qemu/migration/vmstate.c:168
    #3 0x56420688e2ac in vmstate_load /home/elmarco/src/qemu/migration/savevm.c:829
    #4 0x5642068980cb in qemu_loadvm_section_start_full /home/elmarco/src/qemu/migration/savevm.c:2211
    #5 0x564206899645 in qemu_loadvm_state_main /home/elmarco/src/qemu/migration/savevm.c:2395
    #6 0x5642068998cf in qemu_loadvm_state /home/elmarco/src/qemu/migration/savevm.c:2467
    #7 0x56420685f3e9 in process_incoming_migration_co /home/elmarco/src/qemu/migration/migration.c:449
    #8 0x564207106c47 in coroutine_trampoline /home/elmarco/src/qemu/util/coroutine-ucontext.c:115
    #9 0x7f0c0604e37f  (/lib64/libc.so.6+0x4d37f)

Signed-off-by: Marc-André Lureau <[email protected]>
Reviewed-by: Liam Merwick <[email protected]>
Reviewed-by: Li Qiang <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-id: [email protected]
Signed-off-by: Gerd Hoffmann <[email protected]>
tuonga pushed a commit that referenced this issue Aug 26, 2019
There's a race condition in which the tcp_chr_read() ioc handler can
close a connection that is being written to from another thread.

Running iotest 136 in a loop triggers this problem and crashes QEMU.

 (gdb) bt
 #0  0x00005558b842902d in object_get_class (obj=0x0) at qom/object.c:860
 #1  0x00005558b84f92db in qio_channel_writev_full (ioc=0x0, iov=0x7ffc355decf0, niov=1, fds=0x0, nfds=0, errp=0x0) at io/channel.c:76
 #2  0x00005558b84e0e9e in io_channel_send_full (ioc=0x0, buf=0x5558baf5beb0, len=138, fds=0x0, nfds=0) at chardev/char-io.c:123
 #3  0x00005558b84e4a69 in tcp_chr_write (chr=0x5558ba460380, buf=0x5558baf5beb0 "...", len=138) at chardev/char-socket.c:135
 #4  0x00005558b84dca55 in qemu_chr_write_buffer (s=0x5558ba460380, buf=0x5558baf5beb0 "...", len=138, offset=0x7ffc355dedd0, write_all=false) at chardev/char.c:112
 #5  0x00005558b84dcbc2 in qemu_chr_write (s=0x5558ba460380, buf=0x5558baf5beb0 "...", len=138, write_all=false) at chardev/char.c:147
 #6  0x00005558b84dfb26 in qemu_chr_fe_write (be=0x5558ba476610, buf=0x5558baf5beb0 "...", len=138) at chardev/char-fe.c:42
 #7  0x00005558b8088c86 in monitor_flush_locked (mon=0x5558ba476610) at monitor.c:406
 #8  0x00005558b8088e8c in monitor_puts (mon=0x5558ba476610, str=0x5558ba921e49 "") at monitor.c:449
 #9  0x00005558b8089178 in qmp_send_response (mon=0x5558ba476610, rsp=0x5558bb161600) at monitor.c:498
 #10 0x00005558b808920c in monitor_qapi_event_emit (event=QAPI_EVENT_SHUTDOWN, qdict=0x5558bb161600) at monitor.c:526
 #11 0x00005558b8089307 in monitor_qapi_event_queue_no_reenter (event=QAPI_EVENT_SHUTDOWN, qdict=0x5558bb161600) at monitor.c:551
 #12 0x00005558b80896c0 in qapi_event_emit (event=QAPI_EVENT_SHUTDOWN, qdict=0x5558bb161600) at monitor.c:626
 #13 0x00005558b855f23b in qapi_event_send_shutdown (guest=false, reason=SHUTDOWN_CAUSE_HOST_QMP_QUIT) at qapi/qapi-events-run-state.c:43
 #14 0x00005558b81911ef in qemu_system_shutdown (cause=SHUTDOWN_CAUSE_HOST_QMP_QUIT) at vl.c:1837
 #15 0x00005558b8191308 in main_loop_should_exit () at vl.c:1885
 #16 0x00005558b819140d in main_loop () at vl.c:1924
 #17 0x00005558b8198c84 in main (argc=18, argv=0x7ffc355df3f8, envp=0x7ffc355df490) at vl.c:4665

This patch adds a lock to protect tcp_chr_disconnect() and
socket_reconnect_timeout()

Signed-off-by: Alberto Garcia <[email protected]>
Signed-off-by: Andrey Shinkevich <[email protected]>
Message-Id: <1565625509-404969-3-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Paolo Bonzini <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants