From: Eryu Guan <eguan@linux.alibaba.com>
To: qemu-devel@nongnu.org
Subject: [BUG qemu 4.0] segfault when unplugging virtio-blk-pci device
Date: Tue, 31 Dec 2019 18:34:34 +0800 [thread overview]
Message-ID: <20191231103434.GA41863@e18g06458.et15sqa> (raw)
Hi,
I'm using qemu 4.0 and hit segfault when tearing down kata sandbox, I
think it's because io completion hits use-after-free when device is
already gone. Is this a known bug that has been fixed? (I went through
the git log but didn't find anything obvious).
gdb backtrace is:
Core was generated by `/usr/local/libexec/qemu-kvm -name sandbox-5b8df8c6c6901c3c0a9b02879be10fe8d69d6'.
Program terminated with signal 11, Segmentation fault.
#0 object_get_class (obj=obj@entry=0x0) at /usr/src/debug/qemu-4.0/qom/object.c:903
903 return obj->class;
(gdb) bt
#0 object_get_class (obj=obj@entry=0x0) at /usr/src/debug/qemu-4.0/qom/object.c:903
#1 0x0000558a2c009e9b in virtio_notify_vector (vdev=0x558a2e7751d0,
vector=<optimized out>) at /usr/src/debug/qemu-4.0/hw/virtio/virtio.c:1118
#2 0x0000558a2bfdcb1e in virtio_blk_discard_write_zeroes_complete (
opaque=0x558a2f2fd420, ret=0)
at /usr/src/debug/qemu-4.0/hw/block/virtio-blk.c:186
#3 0x0000558a2c261c7e in blk_aio_complete (acb=0x558a2eed7420)
at /usr/src/debug/qemu-4.0/block/block-backend.c:1305
#4 0x0000558a2c3031db in coroutine_trampoline (i0=<optimized out>,
i1=<optimized out>) at /usr/src/debug/qemu-4.0/util/coroutine-ucontext.c:116
#5 0x00007f45b2f8b080 in ?? () from /lib64/libc.so.6
#6 0x00007fff9ed75780 in ?? ()
#7 0x0000000000000000 in ?? ()
It seems like qemu was completing a discard/write_zero request, but
parent BusState was already freed & set to NULL.
Do we need to drain all pending request before unrealizing virtio-blk
device? Like the following patch proposed?
https://lists.gnu.org/archive/html/qemu-devel/2017-06/msg02945.html
If more info is needed, please let me know.
Thanks,
Eryu
next reply other threads:[~2019-12-31 10:35 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-31 10:34 Eryu Guan [this message]
2019-12-31 10:51 ` [BUG qemu 4.0] segfault when unplugging virtio-blk-pci device Igor Mammedov
2020-01-02 2:08 ` Eryu Guan
2020-01-07 13:06 ` Eryu Guan
2020-01-07 14:01 ` Julia Suvorova
2020-01-08 1:54 ` Eryu Guan
2020-01-09 4:58 ` Eryu Guan
2020-01-13 16:38 ` Stefan Hajnoczi
2020-01-14 2:50 ` Eryu Guan
2020-01-14 16:16 ` Stefan Hajnoczi
2020-01-19 8:13 ` Eryu Guan
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