On 2019/11/28 21:36, Stefano Garzarella wrote:
> On Thu, Nov 28, 2019 at 08:09:31PM +0800, pannengy...@huawei.com wrote:
>> From: PanNengyuan <pannengy...@huawei.com>
>>
>> In currently implementation there will be a memory leak when
>> nbd_client_connect() returns error status. Here is an easy way to
>> reproduce:
>>
>> 1. run qemu-iotests as follow and check the result with asan:
>> ./check -raw 143
>>
>> Following is the asan output backtrack:
>> Direct leak of 40 byte(s) in 1 object(s) allocated from:
>> #0 0x7f629688a560 in calloc (/usr/lib64/libasan.so.3+0xc7560)
>> #1 0x7f6295e7e015 in g_malloc0 (/usr/lib64/libglib-2.0.so.0+0x50015)
>> #2 0x56281dab4642 in qobject_input_start_struct
>> /mnt/sdb/qemu-4.2.0-rc0/qapi/qobject-input-visitor.c:295
>> #3 0x56281dab1a04 in visit_start_struct
>> /mnt/sdb/qemu-4.2.0-rc0/qapi/qapi-visit-core.c:49
>> #4 0x56281dad1827 in visit_type_SocketAddress
>> qapi/qapi-visit-sockets.c:386
>> #5 0x56281da8062f in nbd_config
>> /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1716
>> #6 0x56281da8062f in nbd_process_options
>> /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1829
>> #7 0x56281da8062f in nbd_open /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1873
>>
>> Direct leak of 15 byte(s) in 1 object(s) allocated from:
>> #0 0x7f629688a3a0 in malloc (/usr/lib64/libasan.so.3+0xc73a0)
>> #1 0x7f6295e7dfbd in g_malloc (/usr/lib64/libglib-2.0.so.0+0x4ffbd)
>> #2 0x7f6295e96ace in g_strdup (/usr/lib64/libglib-2.0.so.0+0x68ace)
>> #3 0x56281da804ac in nbd_process_options
>> /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1834
>> #4 0x56281da804ac in nbd_open /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1873
>>
>> Indirect leak of 24 byte(s) in 1 object(s) allocated from:
>> #0 0x7f629688a3a0 in malloc (/usr/lib64/libasan.so.3+0xc73a0)
>> #1 0x7f6295e7dfbd in g_malloc (/usr/lib64/libglib-2.0.so.0+0x4ffbd)
>> #2 0x7f6295e96ace in g_strdup (/usr/lib64/libglib-2.0.so.0+0x68ace)
>> #3 0x56281dab41a3 in qobject_input_type_str_keyval
>> /mnt/sdb/qemu-4.2.0-rc0/qapi/qobject-input-visitor.c:536
>> #4 0x56281dab2ee9 in visit_type_str
>> /mnt/sdb/qemu-4.2.0-rc0/qapi/qapi-visit-core.c:297
>> #5 0x56281dad0fa1 in visit_type_UnixSocketAddress_members
>> qapi/qapi-visit-sockets.c:141
>> #6 0x56281dad17b6 in visit_type_SocketAddress_members
>> qapi/qapi-visit-sockets.c:366
>> #7 0x56281dad186a in visit_type_SocketAddress
>> qapi/qapi-visit-sockets.c:393
>> #8 0x56281da8062f in nbd_config /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1716
>> #9 0x56281da8062f in nbd_process_options
>> /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1829
>> #10 0x56281da8062f in nbd_open /mnt/sdb/qemu-4.2.0-rc0/block/nbd.c:1873
>>
>> Reported-by: Euler Robot <euler.ro...@huawei.com>
>> Signed-off-by: PanNengyuan <pannengy...@huawei.com>
>> ---
>> Changes v2 to v1:
>> - add a new function to do the common cleanups (suggested by Stefano
>> Garzarella).
>> ---
>> block/nbd.c | 26 ++++++++++++++++----------
>> 1 file changed, 16 insertions(+), 10 deletions(-)
>>
>> diff --git a/block/nbd.c b/block/nbd.c
>> index 1239761..f8aa2a8 100644
>> --- a/block/nbd.c
>> +++ b/block/nbd.c
>> @@ -94,6 +94,8 @@ typedef struct BDRVNBDState {
>>
>> static int nbd_client_connect(BlockDriverState *bs, Error **errp);
>>
>> +static void nbd_free_bdrvstate_prop(BDRVNBDState *s);
>> +
>> static void nbd_channel_error(BDRVNBDState *s, int ret)
>> {
>> if (ret == -EIO) {
>> @@ -1486,6 +1488,17 @@ static int nbd_client_connect(BlockDriverState *bs,
>> Error **errp)
>> }
>> }
>>
>> +static void nbd_free_bdrvstate_prop(BDRVNBDState *s)
>> +{
>> + object_unref(OBJECT(s->tlscreds));
>> + qapi_free_SocketAddress(s->saddr);
>> + g_free(s->export);
>> + g_free(s->tlscredsid);
>> + if (s->x_dirty_bitmap) {
> ^ it is not needed, g_free() handles NULL pointers.
>> + g_free(s->x_dirty_bitmap);
>> + }
>> +}
>> +
>
> Please, split this patch in two patches:
> - the first patch where you add this function and use it in
> nbd_process_options() and nbd_close()
> - the second patch where you fix the leak in nbd_open()
>
> Thanks,
> Stefano
Thanks, I will change and split it in next version.
>
>> /*
>> * Parse nbd_open options
>> */
>> @@ -1855,10 +1868,7 @@ static int nbd_process_options(BlockDriverState *bs,
>> QDict *options,
>>
>> error:
>> if (ret < 0) {
>> - object_unref(OBJECT(s->tlscreds));
>> - qapi_free_SocketAddress(s->saddr);
>> - g_free(s->export);
>> - g_free(s->tlscredsid);
>> + nbd_free_bdrvstate_prop(s);
>> }
>> qemu_opts_del(opts);
>> return ret;
>> @@ -1881,6 +1891,7 @@ static int nbd_open(BlockDriverState *bs, QDict
>> *options, int flags,
>>
>> ret = nbd_client_connect(bs, errp);
>> if (ret < 0) {
>> + nbd_free_bdrvstate_prop(s);
>> return ret;
>> }
>> /* successfully connected */
>> @@ -1937,12 +1948,7 @@ static void nbd_close(BlockDriverState *bs)
>> BDRVNBDState *s = bs->opaque;
>>
>> nbd_client_close(bs);
>> -
>> - object_unref(OBJECT(s->tlscreds));
>> - qapi_free_SocketAddress(s->saddr);
>> - g_free(s->export);
>> - g_free(s->tlscredsid);
>> - g_free(s->x_dirty_bitmap);
>> + nbd_free_bdrvstate_prop(s);
>> }
>>
>> static int64_t nbd_getlength(BlockDriverState *bs)
>> --
>> 2.7.2.windows.1
>>
>>
>>
>
