Re: [Qemu-devel] [PATCH v1 1/1] qemu/migration: fix the double free problem on from_src_file

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* QingFeng Hao (haoqf@linux.vnet.ibm.com) wrote:
> In load_vmstate, mis->from_src_file is freed twice, the first free is by
> qemu_fclose, the second is by migration_incoming_state_destroy and
> it causes Illegal instruction exception. The fix is just to remove the
> first free.
> 
> This problem is found by qemu-iotests case 068 since commit
> "660819b migration: shut src return path unconditionally". The error is:
> 068 1s ... - output mismatch (see 068.out.bad)
>     --- tests/qemu-iotests/068.out	2017-05-06 01:00:26.417270437 +0200
>     +++ 068.out.bad	2017-06-03 13:59:55.360274640 +0200
>     @@ -6,6 +6,8 @@
>      QEMU X.Y.Z monitor - type 'help' for more information
>      (qemu) savevm 0
>      (qemu) quit
>     +./common.config: line 107: 242472 Illegal instruction     (core dumped) ( if [ -n "${QEMU_NEED_PID}" ]; then
>     +    echo $BASHPID > "${QEMU_TEST_DIR}/qemu-${_QEMU_HANDLE}.pid";
>     +fi; exec "$QEMU_PROG" $QEMU_OPTIONS "$@" )
>      QEMU X.Y.Z monitor - type 'help' for more information
>     -(qemu) quit
>     -*** done
>     +(qemu) *** done
> 
> Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
> ---
>  migration/savevm.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 9c320f59d0..853e14e34e 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -2290,7 +2290,6 @@ int load_snapshot(const char *name, Error **errp)
>  
>      aio_context_acquire(aio_context);
>      ret = qemu_loadvm_state(f);
> -    qemu_fclose(f);
>      aio_context_release(aio_context);

Thanks!

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

>  
>      migration_incoming_state_destroy();
> -- 
> 2.11.2
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK