fix x-no-posted-writes #11

jlevon · 2022-07-21T10:43:28Z

VFIO_USER_NO_REPLY should not be set if we've globally disabled posted
writes.

Signed-off-by: John Levon [email protected]

VFIO_USER_NO_REPLY should not be set if we've globally disabled posted writes. Signed-off-by: John Levon <[email protected]>

The sanitizer reports: ==2534591==ERROR: AddressSanitizer: heap-use-after-free on address 0x60600007f600 at pc 0x557ca6aede56 bp 0x7ffd98571600 sp 0x7ffd985715e0 WRITE of size 8 at 0x60600007f600 thread T0 #0 0x557ca6aede55 in vfio_connect_proxy /home/ctyun/workspace/code/qemu-5.0/hw/vfio/common.c:1936 oracle#1 0x557ca6b32d74 in vfio_user_pci_realize /home/ctyun/workspace/code/qemu-5.0/hw/vfio/pci.c:3649 oracle#2 0x557ca733c425 in pci_qdev_realize hw/pci/pci.c:2098 oracle#3 0x557ca7036370 in device_set_realized hw/core/qdev.c:891 oracle#4 0x557ca7709f27 in property_set_bool qom/object.c:2238 oracle#5 0x557ca771a01e in object_property_set_qobject qom/qom-qobject.c:26 oracle#6 0x557ca77120b8 in object_property_set_bool qom/object.c:1390 oracle#7 0x557ca6f2362e in qdev_device_add /home/ctyun/workspace/code/qemu-5.0/qdev-monitor.c:680 oracle#8 0x557ca6f2419f in qmp_device_add /home/ctyun/workspace/code/qemu-5.0/qdev-monitor.c:805 oracle#9 0x557ca6f24a78 in hmp_device_add /home/ctyun/workspace/code/qemu-5.0/qdev-monitor.c:905 oracle#10 0x557ca7572cdd in handle_hmp_command monitor/hmp.c:1082 oracle#11 0x557ca757323b in monitor_command_cb monitor/hmp.c:47 oracle#12 0x557ca7b0bfc2 in readline_handle_byte util/readline.c:408 oracle#13 0x557ca7573337 in monitor_read monitor/hmp.c:1312 oracle#14 0x557ca7927bee in mux_chr_read chardev/char-mux.c:228 oracle#15 0x557ca7920942 in fd_chr_read chardev/char-fd.c:68 oracle#16 0x7f3f7fa8e183 in g_main_context_dispatch (/usr/lib64/libglib-2.0.so.0+0x51183) oracle#17 0x557ca7aa7caf in glib_pollfds_poll util/main-loop.c:219 oracle#18 0x557ca7aa7caf in os_host_main_loop_wait util/main-loop.c:242 oracle#19 0x557ca7aa7caf in main_loop_wait util/main-loop.c:518 oracle#20 0x557ca6c7e413 in qemu_main_loop /home/ctyun/workspace/code/qemu-5.0/softmmu/vl.c:1710 #21 0x557ca67570fd in main /home/ctyun/workspace/code/qemu-5.0/softmmu/main.c:49 #22 0x7f3f7e256b16 in __libc_start_main (/usr/lib64/libc.so.6+0x25b16) #23 0x557ca675a309 in _start (/root/sibs/qemu-system-x86_64+0x18d7309) 0x60600007f600 is located 32 bytes inside of 64-byte region [0x60600007f5e0,0x60600007f620) freed by thread T1 here: #0 0x7f3f7ff16c89 in free (/usr/lib64/libasan.so.4+0x151c89) oracle#1 0x7f3f7fa93fa8 in g_free (/usr/lib64/libglib-2.0.so.0+0x56fa8) oracle#2 0x557ca770f3bf in object_deinit qom/object.c:654 oracle#3 0x557ca770f3bf in object_finalize qom/object.c:668 oracle#4 0x557ca770f3bf in object_unref qom/object.c:1128 oracle#5 0x557ca7e669cf (/root/sibs/qemu-system-x86_64+0x2fe39cf) previously allocated by thread T0 here: #0 0x7f3f7ff1735b in calloc (/usr/lib64/libasan.so.4+0x15235b) oracle#1 0x7f3f7fa93f00 in g_malloc0 (/usr/lib64/libglib-2.0.so.0+0x56f00) oracle#2 0x557ca733c425 in pci_qdev_realize hw/pci/pci.c:2098 Thread T1 created by T0 here: #0 0x7f3f7ff096ac in __interceptor_pthread_create (/usr/lib64/libasan.so.4+0x1446ac) oracle#1 0x557ca7abaf2f in qemu_thread_create util/qemu-thread-posix.c:556 SUMMARY: AddressSanitizer: heap-use-after-free /home/ctyun/workspace/code/qemu-5.0/hw/vfio/common.c:1936 in vfio_connect_proxy Signed-off-by: Bingsong Si <[email protected]>

in order to avoid requests being stuck in a BlockBackend's request queue during cleanup. Having such requests can lead to a deadlock [0] with a virtio-scsi-pci device using iothread that's busy with IO when initiating a shutdown with QMP 'quit'. There is a race where such a queued request can continue sometime (maybe after bdrv_child_free()?) during bdrv_root_unref_child() [1]. The completion will hold the AioContext lock and wait for the BQL during SCSI completion, but the main thread will hold the BQL and wait for the AioContext as part of bdrv_root_unref_child(), leading to the deadlock [0]. [0]: > Thread 3 (Thread 0x7f3bbd87b700 (LWP 135952) "qemu-system-x86"): > #0 __lll_lock_wait (futex=futex@entry=0x564183365f00 <qemu_global_mutex>, private=0) at lowlevellock.c:52 > #1 0x00007f3bc1c0d843 in __GI___pthread_mutex_lock (mutex=0x564183365f00 <qemu_global_mutex>) at ../nptl/pthread_mutex_lock.c:80 > #2 0x0000564182939f2e in qemu_mutex_lock_impl (mutex=0x564183365f00 <qemu_global_mutex>, file=0x564182b7f774 "../softmmu/physmem.c", line=2593) at ../util/qemu-thread-posix.c:94 > #3 0x000056418247cc2a in qemu_mutex_lock_iothread_impl (file=0x564182b7f774 "../softmmu/physmem.c", line=2593) at ../softmmu/cpus.c:504 > #4 0x00005641826d5325 in prepare_mmio_access (mr=0x5641856148a0) at ../softmmu/physmem.c:2593 > #5 0x00005641826d6fe7 in address_space_stl_internal (as=0x56418679b310, addr=4276113408, val=16418, attrs=..., result=0x0, endian=DEVICE_LITTLE_ENDIAN) at /home/febner/repos/qemu/memory_ldst.c.inc:318 > #6 0x00005641826d7154 in address_space_stl_le (as=0x56418679b310, addr=4276113408, val=16418, attrs=..., result=0x0) at /home/febner/repos/qemu/memory_ldst.c.inc:357 > #7 0x0000564182374b07 in pci_msi_trigger (dev=0x56418679b0d0, msg=...) at ../hw/pci/pci.c:359 > #8 0x000056418237118b in msi_send_message (dev=0x56418679b0d0, msg=...) at ../hw/pci/msi.c:379 > #9 0x0000564182372c10 in msix_notify (dev=0x56418679b0d0, vector=8) at ../hw/pci/msix.c:542 > #10 0x000056418243719c in virtio_pci_notify (d=0x56418679b0d0, vector=8) at ../hw/virtio/virtio-pci.c:77 > #11 0x00005641826933b0 in virtio_notify_vector (vdev=0x5641867a34a0, vector=8) at ../hw/virtio/virtio.c:1985 > #12 0x00005641826948d6 in virtio_irq (vq=0x5641867ac078) at ../hw/virtio/virtio.c:2461 > #13 0x0000564182694978 in virtio_notify (vdev=0x5641867a34a0, vq=0x5641867ac078) at ../hw/virtio/virtio.c:2473 > #14 0x0000564182665b83 in virtio_scsi_complete_req (req=0x7f3bb000e5d0) at ../hw/scsi/virtio-scsi.c:115 > #15 0x00005641826670ce in virtio_scsi_complete_cmd_req (req=0x7f3bb000e5d0) at ../hw/scsi/virtio-scsi.c:641 > #16 0x000056418266736b in virtio_scsi_command_complete (r=0x7f3bb0010560, resid=0) at ../hw/scsi/virtio-scsi.c:712 > #17 0x000056418239aac6 in scsi_req_complete (req=0x7f3bb0010560, status=2) at ../hw/scsi/scsi-bus.c:1526 > #18 0x000056418239e090 in scsi_handle_rw_error (r=0x7f3bb0010560, ret=-123, acct_failed=false) at ../hw/scsi/scsi-disk.c:242 > #19 0x000056418239e13f in scsi_disk_req_check_error (r=0x7f3bb0010560, ret=-123, acct_failed=false) at ../hw/scsi/scsi-disk.c:265 > #20 0x000056418239e482 in scsi_dma_complete_noio (r=0x7f3bb0010560, ret=-123) at ../hw/scsi/scsi-disk.c:340 > #21 0x000056418239e5d9 in scsi_dma_complete (opaque=0x7f3bb0010560, ret=-123) at ../hw/scsi/scsi-disk.c:371 > #22 0x00005641824809ad in dma_complete (dbs=0x7f3bb000d9d0, ret=-123) at ../softmmu/dma-helpers.c:107 > #23 0x0000564182480a72 in dma_blk_cb (opaque=0x7f3bb000d9d0, ret=-123) at ../softmmu/dma-helpers.c:127 > #24 0x00005641827bf78a in blk_aio_complete (acb=0x7f3bb00021a0) at ../block/block-backend.c:1563 > #25 0x00005641827bfa5e in blk_aio_write_entry (opaque=0x7f3bb00021a0) at ../block/block-backend.c:1630 > #26 0x000056418295638a in coroutine_trampoline (i0=-1342102448, i1=32571) at ../util/coroutine-ucontext.c:177 > #27 0x00007f3bc0caed40 in ?? () from /lib/x86_64-linux-gnu/libc.so.6 > #28 0x00007f3bbd8757f0 in ?? () > #29 0x0000000000000000 in ?? () > > Thread 1 (Thread 0x7f3bbe3e9280 (LWP 135944) "qemu-system-x86"): > #0 __lll_lock_wait (futex=futex@entry=0x5641856f2a00, private=0) at lowlevellock.c:52 > #1 0x00007f3bc1c0d8d1 in __GI___pthread_mutex_lock (mutex=0x5641856f2a00) at ../nptl/pthread_mutex_lock.c:115 > #2 0x0000564182939f2e in qemu_mutex_lock_impl (mutex=0x5641856f2a00, file=0x564182c0e319 "../util/async.c", line=728) at ../util/qemu-thread-posix.c:94 > #3 0x000056418293a140 in qemu_rec_mutex_lock_impl (mutex=0x5641856f2a00, file=0x564182c0e319 "../util/async.c", line=728) at ../util/qemu-thread-posix.c:149 > #4 0x00005641829532d5 in aio_context_acquire (ctx=0x5641856f29a0) at ../util/async.c:728 > #5 0x000056418279d5df in bdrv_set_aio_context_commit (opaque=0x5641856e6e50) at ../block.c:7493 > #6 0x000056418294e288 in tran_commit (tran=0x56418630bfe0) at ../util/transactions.c:87 > #7 0x000056418279d880 in bdrv_try_change_aio_context (bs=0x5641856f7130, ctx=0x56418548f810, ignore_child=0x0, errp=0x0) at ../block.c:7626 > #8 0x0000564182793f39 in bdrv_root_unref_child (child=0x5641856f47d0) at ../block.c:3242 > #9 0x00005641827be137 in blk_remove_bs (blk=0x564185709880) at ../block/block-backend.c:914 > #10 0x00005641827bd689 in blk_remove_all_bs () at ../block/block-backend.c:583 > #11 0x0000564182798699 in bdrv_close_all () at ../block.c:5117 > #12 0x000056418248a5b2 in qemu_cleanup () at ../softmmu/runstate.c:821 > #13 0x0000564182738603 in qemu_default_main () at ../softmmu/main.c:38 > #14 0x0000564182738631 in main (argc=30, argv=0x7ffd675a8a48) at ../softmmu/main.c:48 > > (gdb) p *((QemuMutex*)0x5641856f2a00) > $1 = {lock = {__data = {__lock = 2, __count = 2, __owner = 135952, ... > (gdb) p *((QemuMutex*)0x564183365f00) > $2 = {lock = {__data = {__lock = 2, __count = 0, __owner = 135944, ... [1]: > Thread 1 "qemu-system-x86" hit Breakpoint 5, bdrv_drain_all_end () at ../block/io.c:551 > #0 bdrv_drain_all_end () at ../block/io.c:551 > #1 0x00005569810f0376 in bdrv_graph_wrlock (bs=0x0) at ../block/graph-lock.c:156 > #2 0x00005569810bd3e0 in bdrv_replace_child_noperm (child=0x556982e2d7d0, new_bs=0x0) at ../block.c:2897 > #3 0x00005569810bdef2 in bdrv_root_unref_child (child=0x556982e2d7d0) at ../block.c:3227 > #4 0x00005569810e8137 in blk_remove_bs (blk=0x556982e42880) at ../block/block-backend.c:914 > #5 0x00005569810e7689 in blk_remove_all_bs () at ../block/block-backend.c:583 > #6 0x00005569810c2699 in bdrv_close_all () at ../block.c:5117 > #7 0x0000556980db45b2 in qemu_cleanup () at ../softmmu/runstate.c:821 > #8 0x0000556981062603 in qemu_default_main () at ../softmmu/main.c:38 > #9 0x0000556981062631 in main (argc=30, argv=0x7ffd7a82a418) at ../softmmu/main.c:48 > [Switching to Thread 0x7fe76dab2700 (LWP 103649)] > > Thread 3 "qemu-system-x86" hit Breakpoint 4, blk_inc_in_flight (blk=0x556982e42880) at ../block/block-backend.c:1505 > #0 blk_inc_in_flight (blk=0x556982e42880) at ../block/block-backend.c:1505 > #1 0x00005569810e8f36 in blk_wait_while_drained (blk=0x556982e42880) at ../block/block-backend.c:1312 > #2 0x00005569810e9231 in blk_co_do_pwritev_part (blk=0x556982e42880, offset=3422961664, bytes=4096, qiov=0x556983028060, qiov_offset=0, flags=0) at ../block/block-backend.c:1402 > #3 0x00005569810e9a4b in blk_aio_write_entry (opaque=0x556982e2cfa0) at ../block/block-backend.c:1628 > #4 0x000055698128038a in coroutine_trampoline (i0=-2090057872, i1=21865) at ../util/coroutine-ucontext.c:177 > #5 0x00007fe770f50d40 in ?? () from /lib/x86_64-linux-gnu/libc.so.6 > #6 0x00007ffd7a829570 in ?? () > #7 0x0000000000000000 in ?? () Signed-off-by: Fiona Ebner <[email protected]> Message-ID: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>

virtio_load() as a whole should run in coroutine context because it reads from the migration stream and we don't want this to block. However, it calls virtio_set_features_nocheck() and devices don't expect their .set_features callback to run in a coroutine and therefore call functions that may not be called in coroutine context. To fix this, drop out of coroutine context for calling virtio_set_features_nocheck(). Without this fix, the following crash was reported: #0 __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44 #1 0x00007efc738c05d3 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78 #2 0x00007efc73873d26 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26 #3 0x00007efc738477f3 in __GI_abort () at abort.c:79 #4 0x00007efc7384771b in __assert_fail_base (fmt=0x7efc739dbcb8 "", assertion=assertion@entry=0x560aebfbf5cf "!qemu_in_coroutine()", file=file@entry=0x560aebfcd2d4 "../block/graph-lock.c", line=line@entry=275, function=function@entry=0x560aebfcd34d "void bdrv_graph_rdlock_main_loop(void)") at assert.c:92 #5 0x00007efc7386ccc6 in __assert_fail (assertion=0x560aebfbf5cf "!qemu_in_coroutine()", file=0x560aebfcd2d4 "../block/graph-lock.c", line=275, function=0x560aebfcd34d "void bdrv_graph_rdlock_main_loop(void)") at assert.c:101 #6 0x0000560aebcd8dd6 in bdrv_register_buf () #7 0x0000560aeb97ed97 in ram_block_added.llvm () #8 0x0000560aebb8303f in ram_block_add.llvm () #9 0x0000560aebb834fa in qemu_ram_alloc_internal.llvm () #10 0x0000560aebb2ac98 in vfio_region_mmap () #11 0x0000560aebb3ea0f in vfio_bars_register () #12 0x0000560aebb3c628 in vfio_realize () #13 0x0000560aeb90f0c2 in pci_qdev_realize () #14 0x0000560aebc40305 in device_set_realized () #15 0x0000560aebc48e07 in property_set_bool.llvm () #16 0x0000560aebc46582 in object_property_set () #17 0x0000560aebc4cd58 in object_property_set_qobject () #18 0x0000560aebc46ba7 in object_property_set_bool () #19 0x0000560aeb98b3ca in qdev_device_add_from_qdict () #20 0x0000560aebb1fbaf in virtio_net_set_features () #21 0x0000560aebb46b51 in virtio_set_features_nocheck () #22 0x0000560aebb47107 in virtio_load () #23 0x0000560aeb9ae7ce in vmstate_load_state () #24 0x0000560aeb9d2ee9 in qemu_loadvm_state_main () #25 0x0000560aeb9d45e1 in qemu_loadvm_state () #26 0x0000560aeb9bc32c in process_incoming_migration_co.llvm () #27 0x0000560aebeace56 in coroutine_trampoline.llvm () Cc: [email protected] Buglink: https://issues.redhat.com/browse/RHEL-832 Signed-off-by: Kevin Wolf <[email protected]> Message-ID: <[email protected]> Reviewed-by: Stefan Hajnoczi <[email protected]> Signed-off-by: Kevin Wolf <[email protected]>

virtio_load() as a whole should run in coroutine context because it reads from the migration stream and we don't want this to block. However, it calls virtio_set_features_nocheck() and devices don't expect their .set_features callback to run in a coroutine and therefore call functions that may not be called in coroutine context. To fix this, drop out of coroutine context for calling virtio_set_features_nocheck(). Without this fix, the following crash was reported: #0 __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44 #1 0x00007efc738c05d3 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78 #2 0x00007efc73873d26 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26 #3 0x00007efc738477f3 in __GI_abort () at abort.c:79 #4 0x00007efc7384771b in __assert_fail_base (fmt=0x7efc739dbcb8 "", assertion=assertion@entry=0x560aebfbf5cf "!qemu_in_coroutine()", file=file@entry=0x560aebfcd2d4 "../block/graph-lock.c", line=line@entry=275, function=function@entry=0x560aebfcd34d "void bdrv_graph_rdlock_main_loop(void)") at assert.c:92 #5 0x00007efc7386ccc6 in __assert_fail (assertion=0x560aebfbf5cf "!qemu_in_coroutine()", file=0x560aebfcd2d4 "../block/graph-lock.c", line=275, function=0x560aebfcd34d "void bdrv_graph_rdlock_main_loop(void)") at assert.c:101 #6 0x0000560aebcd8dd6 in bdrv_register_buf () #7 0x0000560aeb97ed97 in ram_block_added.llvm () #8 0x0000560aebb8303f in ram_block_add.llvm () #9 0x0000560aebb834fa in qemu_ram_alloc_internal.llvm () #10 0x0000560aebb2ac98 in vfio_region_mmap () #11 0x0000560aebb3ea0f in vfio_bars_register () #12 0x0000560aebb3c628 in vfio_realize () #13 0x0000560aeb90f0c2 in pci_qdev_realize () #14 0x0000560aebc40305 in device_set_realized () #15 0x0000560aebc48e07 in property_set_bool.llvm () #16 0x0000560aebc46582 in object_property_set () #17 0x0000560aebc4cd58 in object_property_set_qobject () #18 0x0000560aebc46ba7 in object_property_set_bool () #19 0x0000560aeb98b3ca in qdev_device_add_from_qdict () #20 0x0000560aebb1fbaf in virtio_net_set_features () #21 0x0000560aebb46b51 in virtio_set_features_nocheck () #22 0x0000560aebb47107 in virtio_load () #23 0x0000560aeb9ae7ce in vmstate_load_state () #24 0x0000560aeb9d2ee9 in qemu_loadvm_state_main () #25 0x0000560aeb9d45e1 in qemu_loadvm_state () #26 0x0000560aeb9bc32c in process_incoming_migration_co.llvm () #27 0x0000560aebeace56 in coroutine_trampoline.llvm () Cc: [email protected] Buglink: https://issues.redhat.com/browse/RHEL-832 Signed-off-by: Kevin Wolf <[email protected]> Message-ID: <[email protected]> Reviewed-by: Stefan Hajnoczi <[email protected]> Signed-off-by: Kevin Wolf <[email protected]> (cherry picked from commit 92e2e6a) Signed-off-by: Michael Tokarev <[email protected]>

Allow overlapping request by removing the assert that made it impossible. There are only two callers: 1. block_copy_task_create() It already asserts the very same condition before calling reqlist_init_req(). 2. cbw_snapshot_read_lock() There is no need to have read requests be non-overlapping in copy-before-write when used for snapshot-access. In fact, there was no protection against two callers of cbw_snapshot_read_lock() calling reqlist_init_req() with overlapping ranges and this could lead to an assertion failure [1]. In particular, with the reproducer script below [0], two cbw_co_snapshot_block_status() callers could race, with the second calling reqlist_init_req() before the first one finishes and removes its conflicting request. [0]: > #!/bin/bash -e > dd if=/dev/urandom of=/tmp/disk.raw bs=1M count=1024 > ./qemu-img create /tmp/fleecing.raw -f raw 1G > ( > ./qemu-system-x86_64 --qmp stdio \ > --blockdev raw,node-name=node0,file.driver=file,file.filename=/tmp/disk.raw \ > --blockdev raw,node-name=node1,file.driver=file,file.filename=/tmp/fleecing.raw \ > <<EOF > {"execute": "qmp_capabilities"} > {"execute": "blockdev-add", "arguments": { "driver": "copy-before-write", "file": "node0", "target": "node1", "node-name": "node3" } } > {"execute": "blockdev-add", "arguments": { "driver": "snapshot-access", "file": "node3", "node-name": "snap0" } } > {"execute": "nbd-server-start", "arguments": {"addr": { "type": "unix", "data": { "path": "/tmp/nbd.socket" } } } } > {"execute": "block-export-add", "arguments": {"id": "exp0", "node-name": "snap0", "type": "nbd", "name": "exp0"}} > EOF > ) & > sleep 5 > while true; do > ./qemu-nbd -d /dev/nbd0 > ./qemu-nbd -c /dev/nbd0 nbd:unix:/tmp/nbd.socket:exportname=exp0 -f raw -r > nbdinfo --map 'nbd+unix:///exp0?socket=/tmp/nbd.socket' > done [1]: > #5 0x000071e5f0088eb2 in __GI___assert_fail (...) at ./assert/assert.c:101 > oracle#6 0x0000615285438017 in reqlist_init_req (...) at ../block/reqlist.c:23 > oracle#7 0x00006152853e2d98 in cbw_snapshot_read_lock (...) at ../block/copy-before-write.c:237 > oracle#8 0x00006152853e3068 in cbw_co_snapshot_block_status (...) at ../block/copy-before-write.c:304 > oracle#9 0x00006152853f4d22 in bdrv_co_snapshot_block_status (...) at ../block/io.c:3726 > oracle#10 0x000061528543a63e in snapshot_access_co_block_status (...) at ../block/snapshot-access.c:48 > oracle#11 0x00006152853f1a0a in bdrv_co_do_block_status (...) at ../block/io.c:2474 > oracle#12 0x00006152853f2016 in bdrv_co_common_block_status_above (...) at ../block/io.c:2652 > oracle#13 0x00006152853f22cf in bdrv_co_block_status_above (...) at ../block/io.c:2732 > oracle#14 0x00006152853d9a86 in blk_co_block_status_above (...) at ../block/block-backend.c:1473 > oracle#15 0x000061528538da6c in blockstatus_to_extents (...) at ../nbd/server.c:2374 > oracle#16 0x000061528538deb1 in nbd_co_send_block_status (...) at ../nbd/server.c:2481 > oracle#17 0x000061528538f424 in nbd_handle_request (...) at ../nbd/server.c:2978 > oracle#18 0x000061528538f906 in nbd_trip (...) at ../nbd/server.c:3121 > oracle#19 0x00006152855a7caf in coroutine_trampoline (...) at ../util/coroutine-ucontext.c:175 Cc: [email protected] Suggested-by: Vladimir Sementsov-Ogievskiy <[email protected]> Signed-off-by: Fiona Ebner <[email protected]> Message-Id: <[email protected]> Reviewed-by: Vladimir Sementsov-Ogievskiy <[email protected]> Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]>

In regime_is_user() we assert if we're passed an ARMMMUIdx_E10_* mmuidx value. This used to make sense because we only used this function in ptw.c and would never use it on this kind of stage 1+2 mmuidx, only for an individual stage 1 or stage 2 mmuidx. However, when we implemented FEAT_E0PD we added a callsite in aa64_va_parameters(), which means this can now be called for stage 1+2 mmuidx values if the guest sets the TCG_ELX.{E0PD0,E0PD1} bits to enable use of the feature. This will then result in an assertion failure later, for instance on a TLBI operation: oracle#6 0x00007ffff6d0e70f in g_assertion_message_expr (domain=0x0, file=0x55555676eeba "../../target/arm/internals.h", line=978, func=0x555556771d48 <__func__.5> "regime_is_user", expr=<optimised out>) at ../../../glib/gtestutils.c:3279 oracle#7 0x0000555555f286d2 in regime_is_user (env=0x555557f2fe00, mmu_idx=ARMMMUIdx_E10_0) at ../../target/arm/internals.h:978 oracle#8 0x0000555555f3e31c in aa64_va_parameters (env=0x555557f2fe00, va=18446744073709551615, mmu_idx=ARMMMUIdx_E10_0, data=true, el1_is_aa32=false) at ../../target/arm/helper.c:12048 oracle#9 0x0000555555f3163b in tlbi_aa64_get_range (env=0x555557f2fe00, mmuidx=ARMMMUIdx_E10_0, value=106721347371041) at ../../target/arm/helper.c:5214 oracle#10 0x0000555555f317e8 in do_rvae_write (env=0x555557f2fe00, value=106721347371041, idxmap=21, synced=true) at ../../target/arm/helper.c:5260 oracle#11 0x0000555555f31925 in tlbi_aa64_rvae1is_write (env=0x555557f2fe00, ri=0x555557fbeae0, value=106721347371041) at ../../target/arm/helper.c:5302 oracle#12 0x0000555556036f8f in helper_set_cp_reg64 (env=0x555557f2fe00, rip=0x555557fbeae0, value=106721347371041) at ../../target/arm/tcg/op_helper.c:965 Since we do know whether these mmuidx values are for usermode or not, we can easily make regime_is_user() handle them: ARMMMUIdx_E10_0 is user, and the other two are not. Cc: [email protected] Fixes: e4c93e4 ("target/arm: Implement FEAT_E0PD") Signed-off-by: Peter Maydell <[email protected]> Reviewed-by: Richard Henderson <[email protected]> Reviewed-by: Alex Bennée <[email protected]> Tested-by: Alex Bennée <[email protected]> Message-id: [email protected]

qemu-ga on a NetBSD -current VM terminates with a SIGSEGV upon receiving 'guest-set-time' command... Core was generated by `qemu-ga'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x000000000cd37a40 in ga_pipe_read_str (fd=fd@entry=0xffffff922a20, str=str@entry=0xffffff922a18) at ../qga/commands-posix.c:88 88 *str[len] = '\0'; [Current thread is 1 (process 1112)] (gdb) bt #0 0x000000000cd37a40 in ga_pipe_read_str (fd=fd@entry=0xffffff922a20, str=str@entry=0xffffff922a18) at ../qga/commands-posix.c:88 #1 0x000000000cd37b60 in ga_run_command (argv=argv@entry=0xffffff922a90, action=action@entry=0xcda34b8 "set hardware clock to system time", errp=errp@entry=0xffffff922a70, in_str=0x0) at ../qga/commands-posix.c:164 #2 0x000000000cd380c4 in qmp_guest_set_time (has_time=<optimized out>, time_ns=<optimized out>, errp=errp@entry=0xffffff922ad0) at ../qga/commands-posix.c:304 #3 0x000000000cd253d8 in qmp_marshal_guest_set_time (args=<optimized out>, ret=<optimized out>, errp=0xffffff922b48) at qga/qga-qapi-commands.c:193 #4 0x000000000cd4e71c in qmp_dispatch (cmds=cmds@entry=0xcdf5b18 <ga_commands>, request=request@entry=0xf3c711a4b000, allow_oob=allow_oob@entry=false, cur_mon=cur_mon@entry=0x0) at ../qapi/qmp-dispatch.c:220 #5 0x000000000cd36524 in process_event (opaque=0xf3c711a79000, obj=0xf3c711a4b000, err=0x0) at ../qga/main.c:677 oracle#6 0x000000000cd526f0 in json_message_process_token (lexer=lexer@entry=0xf3c711a79018, input=0xf3c712072480, type=type@entry=JSON_RCURLY, x=28, y=1) at ../qobject/json-streamer.c:99 oracle#7 0x000000000cd93860 in json_lexer_feed_char (lexer=lexer@entry=0xf3c711a79018, ch=125 '}', flush=flush@entry=false) at ../qobject/json-lexer.c:313 oracle#8 0x000000000cd93a00 in json_lexer_feed (lexer=lexer@entry=0xf3c711a79018, buffer=buffer@entry=0xffffff922d10 "{\"execute\":\"guest-set-time\"}\n", size=<optimized out>) at ../qobject/json-lexer.c:350 oracle#9 0x000000000cd5290c in json_message_parser_feed (parser=parser@entry=0xf3c711a79000, buffer=buffer@entry=0xffffff922d10 "{\"execute\":\"guest-set-time\"}\n", size=<optimized out>) at ../qobject/json-streamer.c:121 oracle#10 0x000000000cd361fc in channel_event_cb (condition=<optimized out>, data=0xf3c711a79000) at ../qga/main.c:703 oracle#11 0x000000000cd3710c in ga_channel_client_event (channel=<optimized out>, condition=<optimized out>, data=0xf3c711b2d300) at ../qga/channel-posix.c:94 oracle#12 0x0000f3c7120d9bec in g_main_dispatch () from /usr/pkg/lib/libglib-2.0.so.0 oracle#13 0x0000f3c7120dd25c in g_main_context_iterate_unlocked.constprop () from /usr/pkg/lib/libglib-2.0.so.0 oracle#14 0x0000f3c7120ddbf0 in g_main_loop_run () from /usr/pkg/lib/libglib-2.0.so.0 oracle#15 0x000000000cda00d8 in run_agent_once (s=0xf3c711a79000) at ../qga/main.c:1522 oracle#16 run_agent (s=0xf3c711a79000) at ../qga/main.c:1559 oracle#17 main (argc=<optimized out>, argv=<optimized out>) at ../qga/main.c:1671 (gdb) The commandline options used on the host machine... qemu-system-aarch64 \ -machine type=virt,pflash0=rom \ -m 8G \ -cpu host \ -smp 8 \ -accel hvf \ -device virtio-net-pci,netdev=unet \ -device virtio-blk-pci,drive=hd \ -drive file=netbsd.qcow2,if=none,id=hd \ -netdev user,id=unet,hostfwd=tcp::2223-:22 \ -object rng-random,filename=/dev/urandom,id=viornd0 \ -device virtio-rng-pci,rng=viornd0 \ -serial mon:stdio \ -display none \ -blockdev node-name=rom,driver=file,filename=/opt/homebrew/Cellar/qemu/9.0.2/share/qemu/edk2-aarch64-code.fd,read-only=true \ -chardev socket,path=/tmp/qga_netbsd.sock,server=on,wait=off,id=qga0 \ -device virtio-serial \ -device virtconsole,chardev=qga0,name=org.qemu.guest_agent.0 This patch rectifies the operator precedence while assigning the NUL terminator. Fixes: c3f32c1 Signed-off-by: Sunil Nimmagadda <[email protected]> Reviewed-by: Konstantin Kostiuk <[email protected]> Reviewed-by: Daniel P. Berrangé <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Konstantin Kostiuk <[email protected]>

The released fix for this CVE: f6b0de5 ("9pfs: prevent opening special files (CVE-2023-2861)") caused a regression with security_model=passthrough. When handling a 'Tmknod' request there was a side effect that 'Tmknod' request could fail as 9p server was trying to adjust permissions: oracle#6 close_if_special_file (fd=30) at ../hw/9pfs/9p-util.h:140 oracle#7 openat_file (mode=<optimized out>, flags=2228224, name=<optimized out>, dirfd=<optimized out>) at ../hw/9pfs/9p-util.h:181 oracle#8 fchmodat_nofollow (dirfd=dirfd@entry=31, name=name@entry=0x5555577ea6e0 "mysocket", mode=493) at ../hw/9pfs/9p-local.c:360 oracle#9 local_set_cred_passthrough (credp=0x7ffbbc4ace10, name=0x5555577ea6e0 "mysocket", dirfd=31, fs_ctx=0x55555811f528) at ../hw/9pfs/9p-local.c:457 oracle#10 local_mknod (fs_ctx=0x55555811f528, dir_path=<optimized out>, name=0x5555577ea6e0 "mysocket", credp=0x7ffbbc4ace10) at ../hw/9pfs/9p-local.c:702 oracle#11 v9fs_co_mknod (pdu=pdu@entry=0x555558121140, fidp=fidp@entry=0x5555574c46c0, name=name@entry=0x7ffbbc4aced0, uid=1000, gid=1000, dev=<optimized out>, mode=49645, stbuf=0x7ffbbc4acef0) at ../hw/9pfs/cofs.c:205 oracle#12 v9fs_mknod (opaque=0x555558121140) at ../hw/9pfs/9p.c:3711 That's because server was opening the special file to adjust permissions, however it was using O_PATH and it would have not returned the file descriptor to guest. So the call to close_if_special_file() on that branch was incorrect. Let's lift the restriction introduced by f6b0de5 such that it would allow to open special files on host if O_PATH flag is supplied, not only for 9p server's own operations as described above, but also for any client 'Topen' request. It is safe to allow opening special files with O_PATH on host, because O_PATH only allows path based operations on the resulting file descriptor and prevents I/O such as read() and write() on that file descriptor. Fixes: f6b0de5 ("9pfs: prevent opening special files (CVE-2023-2861)") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2337 Reported-by: Dirk Herrendorfer <[email protected]> Signed-off-by: Christian Schoenebeck <[email protected]> Reviewed-by: Greg Kurz <[email protected]> Tested-by: Dirk Herrendorfer <[email protected]> Message-Id: <[email protected]>

Found with test sbsaref introduced in [1]. [1] https://patchew.org/QEMU/[email protected]/ ../block/vvfat.c:433:24: runtime error: index 14 out of bounds for type 'uint8_t [11]' #0 0x56151a66b93a in create_long_filename ../block/vvfat.c:433 #1 0x56151a66f3d7 in create_short_and_long_name ../block/vvfat.c:725 #2 0x56151a670403 in read_directory ../block/vvfat.c:804 #3 0x56151a674432 in init_directories ../block/vvfat.c:964 #4 0x56151a67867b in vvfat_open ../block/vvfat.c:1258 #5 0x56151a3b8e19 in bdrv_open_driver ../block.c:1660 oracle#6 0x56151a3bb666 in bdrv_open_common ../block.c:1985 oracle#7 0x56151a3cadb9 in bdrv_open_inherit ../block.c:4153 oracle#8 0x56151a3c8850 in bdrv_open_child_bs ../block.c:3731 oracle#9 0x56151a3ca832 in bdrv_open_inherit ../block.c:4098 oracle#10 0x56151a3cbe40 in bdrv_open ../block.c:4248 oracle#11 0x56151a46344f in blk_new_open ../block/block-backend.c:457 oracle#12 0x56151a388bd9 in blockdev_init ../blockdev.c:612 oracle#13 0x56151a38ab2d in drive_new ../blockdev.c:1006 oracle#14 0x5615190fca41 in drive_init_func ../system/vl.c:649 oracle#15 0x56151aa796dd in qemu_opts_foreach ../util/qemu-option.c:1135 oracle#16 0x5615190fd2b6 in configure_blockdev ../system/vl.c:708 oracle#17 0x56151910a307 in qemu_create_early_backends ../system/vl.c:2004 oracle#18 0x561519113fcf in qemu_init ../system/vl.c:3685 oracle#19 0x56151a7e438e in main ../system/main.c:47 oracle#20 0x7f72d1a46249 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #21 0x7f72d1a46304 in __libc_start_main_impl ../csu/libc-start.c:360 #22 0x561517e98510 in _start (/home/user/.work/qemu/build/qemu-system-aarch64+0x3b9b510) The offset used can easily go beyond entry->name size. It's probably a bug, but I don't have the time to dive into vfat specifics for now. This change solves the ubsan issue, and is functionally equivalent, as anything written past the entry->name array would not be read anyway. Signed-off-by: Pierrick Bouvier <[email protected]> Reviewed-by: Michael Tokarev <[email protected]> Signed-off-by: Michael Tokarev <[email protected]>

ASAN detected a leak when running the ahci-test /ahci/io/dma/lba28/retry: Direct leak of 35 byte(s) in 1 object(s) allocated from: #0 in malloc #1 in __vasprintf_internal #2 in vasprintf #3 in g_vasprintf #4 in g_strdup_vprintf #5 in g_strdup_printf oracle#6 in object_get_canonical_path ../qom/object.c:2096:19 oracle#7 in blk_get_attached_dev_id_or_path ../block/block-backend.c:1033:12 oracle#8 in blk_get_attached_dev_path ../block/block-backend.c:1047:12 oracle#9 in send_qmp_error_event ../block/block-backend.c:2140:36 oracle#10 in blk_error_action ../block/block-backend.c:2172:9 oracle#11 in ide_handle_rw_error ../hw/ide/core.c:875:5 oracle#12 in ide_dma_cb ../hw/ide/core.c:894:13 oracle#13 in dma_complete ../system/dma-helpers.c:107:9 oracle#14 in dma_blk_cb ../system/dma-helpers.c:129:9 oracle#15 in blk_aio_complete ../block/block-backend.c:1552:9 oracle#16 in blk_aio_write_entry ../block/block-backend.c:1619:5 oracle#17 in coroutine_trampoline ../util/coroutine-ucontext.c:175:9 Plug the leak by freeing the device path string. Signed-off-by: Fabiano Rosas <[email protected]> Reviewed-by: Philippe Mathieu-Daudé <[email protected]> Message-ID: <[email protected]> [PMD: Use g_autofree] Signed-off-by: Philippe Mathieu-Daudé <[email protected]> Message-ID: <[email protected]> Signed-off-by: Kevin Wolf <[email protected]>

Dumping coroutines don't yet work with coredumps. Let's make it work. We still kept most of the old code because they can be either more flexible, or prettier. Only add the fallbacks when they stop working. Currently the raw unwind is pretty ugly, but it works, like this: (gdb) qemu bt #0 process_incoming_migration_co (opaque=0x0) at ../migration/migration.c:788 #1 0x000055ae6c0dc4d9 in coroutine_trampoline (i0=-1711718576, i1=21934) at ../util/coroutine-ucontext.c:175 #2 0x00007f9f59d72f40 in ??? () at /lib64/libc.so.6 #3 0x00007ffd549214a0 in ??? () #4 0x0000000000000000 in ??? () Coroutine at 0x7f9f4c57c748: #0 0x55ae6c0dc9a8 in qemu_coroutine_switch<+120> () at ../util/coroutine-ucontext.c:321 #1 0x55ae6c0da2f8 in qemu_aio_coroutine_enter<+356> () at ../util/qemu-coroutine.c:293 #2 0x55ae6c0da3f1 in qemu_coroutine_enter<+34> () at ../util/qemu-coroutine.c:316 #3 0x55ae6baf775e in migration_incoming_process<+43> () at ../migration/migration.c:876 #4 0x55ae6baf7ab4 in migration_ioc_process_incoming<+490> () at ../migration/migration.c:1008 #5 0x55ae6bae9ae7 in migration_channel_process_incoming<+145> () at ../migration/channel.c:45 oracle#6 0x55ae6bb18e35 in socket_accept_incoming_migration<+118> () at ../migration/socket.c:132 oracle#7 0x55ae6be939ef in qio_net_listener_channel_func<+131> () at ../io/net-listener.c:54 oracle#8 0x55ae6be8ce1a in qio_channel_fd_source_dispatch<+78> () at ../io/channel-watch.c:84 oracle#9 0x7f9f5b26728c in g_main_context_dispatch_unlocked.lto_priv<+315> () oracle#10 0x7f9f5b267555 in g_main_context_dispatch<+36> () oracle#11 0x55ae6c0d91a7 in glib_pollfds_poll<+90> () at ../util/main-loop.c:287 oracle#12 0x55ae6c0d9235 in os_host_main_loop_wait<+128> () at ../util/main-loop.c:310 oracle#13 0x55ae6c0d9364 in main_loop_wait<+203> () at ../util/main-loop.c:589 oracle#14 0x55ae6bac212a in qemu_main_loop<+41> () at ../system/runstate.c:835 oracle#15 0x55ae6bfdf522 in qemu_default_main<+19> () at ../system/main.c:37 oracle#16 0x55ae6bfdf55f in main<+40> () at ../system/main.c:48 oracle#17 0x7f9f59d42248 in __libc_start_call_main<+119> () oracle#18 0x7f9f59d4230b in __libc_start_main_impl<+138> () Signed-off-by: Peter Xu <[email protected]> Message-ID: <[email protected]> Reviewed-by: Kevin Wolf <[email protected]> Signed-off-by: Kevin Wolf <[email protected]>

Regression introduced by cf76c4 (hw/misc: Add nr_regs and cold_reset_values to NPCM CLK) cold_reset_values has a different size, depending on device used (NPCM7xx vs NPCM8xx). However, s->regs has a fixed size, which matches NPCM8xx. Thus, when initializing a NPCM7xx, we go past cold_reset_values ending. Report by asan: ==2066==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55d68a3e97f0 at pc 0x7fcaf2b2d14b bp 0x7ffff0cc3890 sp 0x7ffff0cc3040 READ of size 196 at 0x55d68a3e97f0 thread T0 #0 0x7fcaf2b2d14a in __interceptor_memcpy ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827 #1 0x55d688447e0d in memcpy /usr/include/x86_64-linux-gnu/bits/string_fortified.h:29 #2 0x55d688447e0d in npcm_clk_enter_reset ../hw/misc/npcm_clk.c:968 #3 0x55d6899b7213 in resettable_phase_enter ../hw/core/resettable.c:136 #4 0x55d6899a1ef7 in bus_reset_child_foreach ../hw/core/bus.c:97 #5 0x55d6899b717d in resettable_child_foreach ../hw/core/resettable.c:92 oracle#6 0x55d6899b717d in resettable_phase_enter ../hw/core/resettable.c:129 oracle#7 0x55d6899b4ead in resettable_container_child_foreach ../hw/core/resetcontainer.c:54 oracle#8 0x55d6899b717d in resettable_child_foreach ../hw/core/resettable.c:92 oracle#9 0x55d6899b717d in resettable_phase_enter ../hw/core/resettable.c:129 oracle#10 0x55d6899b7bfa in resettable_assert_reset ../hw/core/resettable.c:55 oracle#11 0x55d6899b8666 in resettable_reset ../hw/core/resettable.c:45 oracle#12 0x55d688d15cd2 in qemu_system_reset ../system/runstate.c:527 oracle#13 0x55d687fc5edd in qdev_machine_creation_done ../hw/core/machine.c:1738 oracle#14 0x55d688d209bd in qemu_machine_creation_done ../system/vl.c:2779 oracle#15 0x55d688d209bd in qmp_x_exit_preconfig ../system/vl.c:2807 oracle#16 0x55d688d281fb in qemu_init ../system/vl.c:3838 oracle#17 0x55d687ceab12 in main ../system/main.c:68 oracle#18 0x7fcaef006249 (/lib/x86_64-linux-gnu/libc.so.6+0x27249) oracle#19 0x7fcaef006304 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x27304) oracle#20 0x55d687cf0010 in _start (/home/runner/work/qemu-ci/qemu-ci/build/qemu-system-arm+0x371c010) 0x55d68a3e97f0 is located 0 bytes to the right of global variable 'npcm7xx_cold_reset_values' defined in '../hw/misc/npcm_clk.c:134:23' (0x55d68a3e9780) of size 112 Impacted tests: Summary of Failures: check: 2/747 qemu:qtest+qtest-aarch64 / qtest-aarch64/qom-test ERROR 9.28s killed by signal 6 SIGABRT 4/747 qemu:qtest+qtest-arm / qtest-arm/qom-test ERROR 7.82s killed by signal 6 SIGABRT 32/747 qemu:qtest+qtest-aarch64 / qtest-aarch64/device-introspect-test ERROR 10.91s killed by signal 6 SIGABRT 35/747 qemu:qtest+qtest-arm / qtest-arm/device-introspect-test ERROR 11.33s killed by signal 6 SIGABRT 114/747 qemu:qtest+qtest-arm / qtest-arm/npcm7xx_pwm-test ERROR 0.98s killed by signal 6 SIGABRT 115/747 qemu:qtest+qtest-aarch64 / qtest-aarch64/test-hmp ERROR 2.95s killed by signal 6 SIGABRT 117/747 qemu:qtest+qtest-arm / qtest-arm/test-hmp ERROR 2.54s killed by signal 6 SIGABRT 151/747 qemu:qtest+qtest-arm / qtest-arm/npcm7xx_watchdog_timer-test ERROR 0.96s killed by signal 6 SIGABRT 247/747 qemu:qtest+qtest-arm / qtest-arm/npcm7xx_adc-test ERROR 0.96s killed by signal 6 SIGABRT 248/747 qemu:qtest+qtest-arm / qtest-arm/npcm7xx_gpio-test ERROR 1.05s killed by signal 6 SIGABRT 249/747 qemu:qtest+qtest-arm / qtest-arm/npcm7xx_rng-test ERROR 0.97s killed by signal 6 SIGABRT 250/747 qemu:qtest+qtest-arm / qtest-arm/npcm7xx_sdhci-test ERROR 0.97s killed by signal 6 SIGABRT 251/747 qemu:qtest+qtest-arm / qtest-arm/npcm7xx_smbus-test ERROR 0.89s killed by signal 6 SIGABRT 252/747 qemu:qtest+qtest-arm / qtest-arm/npcm7xx_timer-test ERROR 1.09s killed by signal 6 SIGABRT 253/747 qemu:qtest+qtest-arm / qtest-arm/npcm_gmac-test ERROR 1.12s killed by signal 6 SIGABRT 255/747 qemu:qtest+qtest-arm / qtest-arm/npcm7xx_emc-test ERROR 1.05s killed by signal 6 SIGABRT check-functional: 22/203 qemu:func-thorough+func-arm-thorough+thorough / func-arm-arm_quanta_gsj ERROR 0.79s exit status 1 38/203 qemu:func-quick+func-aarch64 / func-aarch64-migration ERROR 1.97s exit status 1 45/203 qemu:func-quick+func-arm / func-arm-migration ERROR 1.90s exit status 1 Fixes: cf76c4e ("hw/misc: Add nr_regs and cold_reset_values to NPCM CLK") Signed-off-by: Pierrick Bouvier <[email protected]> Reviewed-by: Hao Wu <[email protected]> Signed-off-by: Peter Maydell <[email protected]>

On the incoming migration side, QEMU uses a coroutine to load all the VM states. Inside, it may reference MigrationState on global states like migration capabilities, parameters, error state, shared mutexes and more. However there's nothing yet to make sure MigrationState won't get destroyed (e.g. after migration_shutdown()). Meanwhile there's also no API available to remove the incoming coroutine in migration_shutdown(), avoiding it to access the freed elements. There's a bug report showing this can happen and crash dest QEMU when migration is cancelled on source. When it happens, the dest main thread is trying to cleanup everything: #0 qemu_aio_coroutine_enter #1 aio_dispatch_handler #2 aio_poll #3 monitor_cleanup #4 qemu_cleanup #5 qemu_default_main Then it found the migration incoming coroutine, schedule it (even after migration_shutdown()), causing crash: #0 __pthread_kill_implementation #1 __pthread_kill_internal #2 __GI_raise #3 __GI_abort #4 __assert_fail_base #5 __assert_fail oracle#6 qemu_mutex_lock_impl oracle#7 qemu_lockable_mutex_lock oracle#8 qemu_lockable_lock oracle#9 qemu_lockable_auto_lock oracle#10 migrate_set_error oracle#11 process_incoming_migration_co oracle#12 coroutine_trampoline To fix it, take a refcount after an incoming setup is properly done when qmp_migrate_incoming() succeeded the 1st time. As it's during a QMP handler which needs BQL, it means the main loop is still alive (without going into cleanups, which also needs BQL). Releasing the refcount now only until the incoming migration coroutine finished or failed. Hence the refcount is valid for both (1) setup phase of incoming ports, mostly IO watches (e.g. qio_channel_add_watch_full()), and (2) the incoming coroutine itself (process_incoming_migration_co()). Note that we can't unref in migration_incoming_state_destroy(), because both qmp_xen_load_devices_state() and load_snapshot() will use it without an incoming migration. Those hold BQL so they're not prone to this issue. PS: I suspect nobody uses Xen's command at all, as it didn't register yank, hence AFAIU the command should crash on master when trying to unregister yank in migration_incoming_state_destroy().. but that's another story. Also note that in some incoming failure cases we may not always unref the MigrationState refcount, which is a trade-off to keep things simple. We could make it accurate, but it can be an overkill. Some examples: - Unlike most of the rest protocols, socket_start_incoming_migration() may create net listener after incoming port setup sucessfully. It means we can't unref in migration_channel_process_incoming() as a generic path because socket protocol might keep using MigrationState. - For either socket or file, multiple IO watches might be created, it means logically each IO watch needs to take one refcount for MigrationState so as to be 100% accurate on ownership of refcount taken. In general, we at least need per-protocol handling to make it accurate, which can be an overkill if we know incoming failed after all. Add a short comment to explain that when taking the refcount in qmp_migrate_incoming(). Bugzilla: https://issues.redhat.com/browse/RHEL-69775 Tested-by: Yan Fu <[email protected]> Signed-off-by: Peter Xu <[email protected]> Reviewed-by: Fabiano Rosas <[email protected]> Message-ID: <[email protected]> Signed-off-by: Fabiano Rosas <[email protected]>

ASAN spotted a leaking string in machine_set_loadparm(): Direct leak of 9 byte(s) in 1 object(s) allocated from: #0 0x560ffb5bb379 in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:69:3 #1 0x7f1aca926518 in g_malloc ../glib/gmem.c:106 #2 0x7f1aca94113e in g_strdup ../glib/gstrfuncs.c:364 #3 0x560ffc8afbf9 in qobject_input_type_str ../qapi/qobject-input-visitor.c:542:12 #4 0x560ffc8a80ff in visit_type_str ../qapi/qapi-visit-core.c:349:10 #5 0x560ffbe6053a in machine_set_loadparm ../hw/s390x/s390-virtio-ccw.c:802:10 oracle#6 0x560ffc0c5e52 in object_property_set ../qom/object.c:1450:5 oracle#7 0x560ffc0d4175 in object_property_set_qobject ../qom/qom-qobject.c:28:10 oracle#8 0x560ffc0c6004 in object_property_set_str ../qom/object.c:1458:15 oracle#9 0x560ffbe2ae60 in update_machine_ipl_properties ../hw/s390x/ipl.c:569:9 oracle#10 0x560ffbe2aa65 in s390_ipl_update_diag308 ../hw/s390x/ipl.c:594:5 oracle#11 0x560ffbdee132 in handle_diag_308 ../target/s390x/diag.c:147:9 oracle#12 0x560ffbebb956 in helper_diag ../target/s390x/tcg/misc_helper.c:137:9 oracle#13 0x7f1a3c51c730 (/memfd:tcg-jit (deleted)+0x39730) Cc: [email protected] Signed-off-by: Fabiano Rosas <[email protected]> Message-ID: <[email protected]> Fixes: 1fd396e ("s390x: Register TYPE_S390_CCW_MACHINE properties as class properties") Reviewed-by: Thomas Huth <[email protected]> Reviewed-by: Philippe Mathieu-Daudé <[email protected]> Signed-off-by: Thomas Huth <[email protected]>

fix x-no-posted-writes

d0e6d83

VFIO_USER_NO_REPLY should not be set if we've globally disabled posted writes. Signed-off-by: John Levon <[email protected]>

bingsong mentioned this pull request May 22, 2023

vfio/pci: Fix VFIOGroup use after free #14

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fix x-no-posted-writes #11

fix x-no-posted-writes #11

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jlevon commented Jul 21, 2022

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fix x-no-posted-writes #11

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fix x-no-posted-writes #11

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jlevon commented Jul 21, 2022

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