Re: [PATCH] bugfix: hostmem: Free host_nodes list right after visited

[Igor Mammedov]

On Wed, 9 Dec 2020 10:56:48 +0800
Keqian Zhu <zhukeqian1@huawei.com> wrote:

> In host_memory_backend_get_host_nodes, we build host_nodes
> list and output it to v (a StringOutputVisitor) but forget
> to free the list. This fixes the memory leak.
> 
> The memory leak stack:
> 
> ==qemu-kvm==209357==ERROR: LeakSanitizer: detected memory leaks
> Direct leak of 32 byte(s) in 2 object(s) allocated from:
>   #0 0xfffe430e3393 in __interceptor_calloc (/lib64/libasan.so.4+0xd3393)  
> ??:?
>   #1 0xfffe41d58b9b in g_malloc0 (/lib64/libglib-2.0.so.0+0x58b9b)  ??:?
>   #2 0xaaac0cdb6e43 (/usr/libexec/qemu-kvm+0xe16e43)  backends/hostmem.c:94
>   #3 0xaaac0d2edf83 (/usr/libexec/qemu-kvm+0x134df83) qom/object.c:1478
>   #4 0xaaac0c976513 (/usr/libexec/qemu-kvm+0x9d6513)  
> hw/core/machine-qmp-cmds.c:312
>   #5 0xaaac0d2e980b (/usr/libexec/qemu-kvm+0x134980b) qom/object.c:1001
>   #6 0xaaac0c97779b (/usr/libexec/qemu-kvm+0x9d779b)  
> hw/core/machine-qmp-cmds.c:328 (discriminator 1)
>   #7 0xaaac0d26ed3f (/usr/libexec/qemu-kvm+0x12ced3f) 
> qapi/qapi-commands-machine.c:327
>   #8 0xaaac0d43d647 (/usr/libexec/qemu-kvm+0x149d647) qapi/qmp-dispatch.c:147
>   #9 0xaaac0d21f74b (/usr/libexec/qemu-kvm+0x127f74b) monitor/qmp.c:120
>   #10 0xaaac0d22074b (/usr/libexec/qemu-kvm+0x128074b) monitor/qmp.c:209 
> (discriminator 4)
>   #11 0xaaac0d4daefb (/usr/libexec/qemu-kvm+0x153aefb) util/async.c:117
>   #12 0xaaac0d4e30fb (/usr/libexec/qemu-kvm+0x15430fb) util/aio-posix.c:459
>   #13 0xaaac0d4dac8f (/usr/libexec/qemu-kvm+0x153ac8f) util/async.c:268
>   #14 0xfffe41d52a6b in g_main_context_dispatch 
> (/lib64/libglib-2.0.so.0+0x52a6b)  ??:?
>   #15 0xaaac0d4e0e97 (/usr/libexec/qemu-kvm+0x1540e97)  util/main-loop.c:218
>   #16 0xaaac0cd9bfa7 (/usr/libexec/qemu-kvm+0xdfbfa7)  vl.c:1791
>   #17 0xaaac0c823bc3 (/usr/libexec/qemu-kvm+0x883bc3)  vl.c:4473
>   #18 0xfffe40ab3ebf in __libc_start_main (/lib64/libc.so.6+0x23ebf)  ??:?
>   #19 0xaaac0c82ed5f (/usr/libexec/qemu-kvm+0x88ed5f)  ??:?
> SUMMARY: AddressSanitizer: 32 byte(s) leaked in 2 allocation(s).
> 
> Fixes: 4cf1b76bf1e2 (hostmem: add properties for NUMA memory policy)
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  backends/hostmem.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/backends/hostmem.c b/backends/hostmem.c
> index 4bde00e8e7..9f9ac95edd 100644
> --- a/backends/hostmem.c
> +++ b/backends/hostmem.c
> @@ -105,6 +105,7 @@ host_memory_backend_get_host_nodes(Object *obj, Visitor 
> *v, const char *name,
>  
>  ret:
>      visit_type_uint16List(v, name, &host_nodes, errp);
> +    qapi_free_uint16List(host_nodes);
>  }
>  
>  static void