[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v3 00/10] curl: fix curl read
From: |
Fam Zheng |
Subject: |
Re: [Qemu-devel] [PATCH v3 00/10] curl: fix curl read |
Date: |
Wed, 22 May 2013 10:52:53 +0800 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Tue, 05/21 08:39, Richard W.M. Jones wrote:
> On Tue, May 21, 2013 at 09:54:15AM +0800, Fam Zheng wrote:
> > On Mon, 05/20 09:49, Richard W.M. Jones wrote:
> > > On Mon, May 20, 2013 at 09:41:06AM +0100, Richard W.M. Jones wrote:
> > > > On Mon, May 20, 2013 at 03:03:34PM +0800, Fam Zheng wrote:
> > > > > CURL library API has changed, the current curl driver is not working.
> > > > > This patch rewrites the use of API as well as the structure of
> > > > > internal
> > > > > states.
> > > >
> > > > I tried this, but it segfaults:
> > > >
> > > > Program terminated with signal 11, Segmentation fault.
> > >
> > > That stack trace was wrong. I was testing against the version of
> > > libcurl in Fedora which is known to be broken.
> > >
> > > Here is the stack trace, this time really running against
> > > curl-7_30_0-147-gae26ee3:
> > >
> > > Program terminated with signal 11, Segmentation fault.
> > > #0 curl_read_cb (ptr=<optimized out>, size=<optimized out>,
> > > nmemb=<optimized out>, opaque=0x7f63d48ba340) at block/curl.c:240
> > > 240 size_t aio_base = acb->sector_num * SECTOR_SIZE;
> >
> > Looks like a memory corrupt (QLIST head is invalid pointer). But I can't
> > reproduce here with your steps. Can you try qemu-io?
> >
> > $LD_LIBRARY_PATH=~/d/curl/lib/.libs ~/d/qemu/qemu-io
> > http://192.168.0.249/scratch/winxp.img -c 'read 0 512'
>
> This command is successful:
>
> $ LD_LIBRARY_PATH=~/d/curl/lib/.libs ~/d/qemu/qemu-io
> http://192.168.0.249/scratch/winxp.img -c 'read 0 512'
> read 512/512 bytes at offset 0
> 512 bytes, 1 ops; 0.0000 sec (32.552 MiB/sec and 66666.6667 ops/sec)
> $ echo $?
> 0
>
> Here's another go with guestfish:
>
> $ ulimit -c unlimited
> $ LIBGUESTFS_DEBUG=1 LIBGUESTFS_TRACE=1 LIBGUESTFS_BACKEND=direct
> LIBGUESTFS_QEMU=~/d/qemu/qemu.wrapper LD_LIBRARY_PATH=~/d/curl/lib/.libs
> PATH=~/d/qemu:$PATH ./run ./fish/guestfish -a
> http://192.168.0.249/scratch/winxp.img -i
> [...]
> [00159ms] /home/rjones/d/qemu/qemu.wrapper \
> -global virtio-blk-pci.scsi=off \
> -nodefconfig \
> -nodefaults \
> -nographic \
> -device virtio-scsi-pci,id=scsi \
> -drive file=http://192.168.0.249/scratch/winxp.img,id=hd0,if=none \
> -device scsi-hd,drive=hd0 \
> -drive
> file=/home/rjones/d/libguestfs/tmp/.guestfs-1000/root.15535,snapshot=on,id=appliance,if=none,cache=unsafe
> \
> -device scsi-hd,drive=appliance \
> -machine accel=kvm:tcg \
> -m 500 \
> -no-reboot \
> -no-hpet \
> -device virtio-serial \
> -serial stdio \
> -device sga \
> -chardev
> socket,path=/home/rjones/d/libguestfs/tmp/libguestfsk9fu9P/guestfsd.sock,id=channel0
> \
> -device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \
> -kernel /home/rjones/d/libguestfs/tmp/.guestfs-1000/kernel.15535 \
> -initrd /home/rjones/d/libguestfs/tmp/.guestfs-1000/initrd.15535 \
> -append 'panic=1 console=ttyS0 udevtimeout=600 no_timer_check acpi=off
> printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0 guestfs_verbose=1
> TERM=xterm-256color'libguestfs: error: appliance closed the connection
> unexpectedly, see earlier error messages
> libguestfs: child_cleanup: 0x1db0090: child process died
> libguestfs: sending SIGTERM to process 15600
> libguestfs: error: /home/rjones/d/qemu/qemu.wrapper killed by signal 11
> (Segmentation fault), see debug messages above
> libguestfs: error: guestfs_launch failed, see earlier error messages
> libguestfs: trace: launch = -1 (error)
> [...]
>
> $ file /tmp/core.15600
> /tmp/core.15600: ELF 64-bit LSB core file x86-64, version 1 (SYSV),
> SVR4-style, from '/home/rjones/d/qemu/x86_64-softmmu/qemu-system-x86_64 -L
> /home/rjones/d/qemu/pc'
>
> $ gdb /home/rjones/d/qemu/x86_64-softmmu/qemu-system-x86_64 /tmp/core.15600
>
> [stack trace is the same as before]
>
> #0 curl_read_cb (ptr=<optimized out>, size=<optimized out>,
> nmemb=<optimized out>, opaque=0x7f4d3c769360) at block/curl.c:240
> 240 size_t aio_base = acb->sector_num * SECTOR_SIZE;
> (gdb) print acb
> $1 = (CURLAIOCB *) 0x7575757575757575
>
> Looks like use-after-free?
Yes, thank you a lot. Will post another version to fix this.
--
Fam
- [Qemu-devel] [PATCH v3 05/10] curl: add timer to BDRVCURLState, (continued)
- [Qemu-devel] [PATCH v3 05/10] curl: add timer to BDRVCURLState, Fam Zheng, 2013/05/20
- [Qemu-devel] [PATCH v3 06/10] curl: introduce CURLDataCache, Fam Zheng, 2013/05/20
- [Qemu-devel] [PATCH v3 07/10] curl: make use of CURLDataCache., Fam Zheng, 2013/05/20
- [Qemu-devel] [PATCH v3 08/10] curl: use list to store CURLState, Fam Zheng, 2013/05/20
- [Qemu-devel] [PATCH v3 09/10] curl: add cache quota., Fam Zheng, 2013/05/20
- [Qemu-devel] [PATCH v3 10/10] curl: introduce ssl_no_cert runtime option., Fam Zheng, 2013/05/20
- Re: [Qemu-devel] [PATCH v3 00/10] curl: fix curl read, Richard W.M. Jones, 2013/05/20