block: fix memleaks in bdrv_refresh_filename

[PATCH] block: fix memleaks in bdrv_refresh_filename

Posted by pannengyuan@huawei.com 4 years, 3 months ago

From: Pan Nengyuan <pannengyuan@huawei.com>

If we call the qmp 'query-block' while qemu is working on
'block-commit', it will cause memleaks, the memory leak stack is as
follow:

Indirect leak of 12360 byte(s) in 3 object(s) allocated from:
    #0 0x7f80f0b6d970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
    #1 0x7f80ee86049d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
    #2 0x55ea95b5bb67 in qdict_new /mnt/sdb/qemu-4.2.0-rc0/qobject/qdict.c:29
    #3 0x55ea956cd043 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6427
    #4 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
    #5 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
    #6 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
    #7 0x55ea958818ea in bdrv_block_device_info /mnt/sdb/qemu-4.2.0-rc0/block/qapi.c:56
    #8 0x55ea958879de in bdrv_query_info /mnt/sdb/qemu-4.2.0-rc0/block/qapi.c:392
    #9 0x55ea9588b58f in qmp_query_block /mnt/sdb/qemu-4.2.0-rc0/block/qapi.c:578
    #10 0x55ea95567392 in qmp_marshal_query_block qapi/qapi-commands-block-core.c:95

Indirect leak of 4120 byte(s) in 1 object(s) allocated from:
    #0 0x7f80f0b6d970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
    #1 0x7f80ee86049d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
    #2 0x55ea95b5bb67 in qdict_new /mnt/sdb/qemu-4.2.0-rc0/qobject/qdict.c:29
    #3 0x55ea956cd043 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6427
    #4 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
    #5 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
    #6 0x55ea9569f301 in bdrv_backing_attach /mnt/sdb/qemu-4.2.0-rc0/block.c:1064
    #7 0x55ea956a99dd in bdrv_replace_child_noperm /mnt/sdb/qemu-4.2.0-rc0/block.c:2283
    #8 0x55ea956b9b53 in bdrv_replace_node /mnt/sdb/qemu-4.2.0-rc0/block.c:4196
    #9 0x55ea956b9e49 in bdrv_append /mnt/sdb/qemu-4.2.0-rc0/block.c:4236
    #10 0x55ea958c3472 in commit_start /mnt/sdb/qemu-4.2.0-rc0/block/commit.c:306
    #11 0x55ea94b68ab0 in qmp_block_commit /mnt/sdb/qemu-4.2.0-rc0/blockdev.c:3459
    #12 0x55ea9556a7a7 in qmp_marshal_block_commit qapi/qapi-commands-block-core.c:407

Fixes: bb808d5f5c0978828a974d547e6032402c339555
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
---
 block.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block.c b/block.c
index ecd09dbbfd..177eb8ade0 100644
--- a/block.c
+++ b/block.c
@@ -6419,6 +6419,7 @@ void bdrv_refresh_filename(BlockDriverState *bs)
                 child->bs->exact_filename);
         pstrcpy(bs->filename, sizeof(bs->filename), child->bs->filename);
 
+        qobject_unref(bs->full_open_options);
         bs->full_open_options = qobject_ref(child->bs->full_open_options);
 
         return;
-- 
2.21.0.windows.1

Re: [PATCH] block: fix memleaks in bdrv_refresh_filename

Posted by Max Reitz 4 years, 3 months ago

On 16.01.20 09:56, pannengyuan@huawei.com wrote:
> From: Pan Nengyuan <pannengyuan@huawei.com>
> 
> If we call the qmp 'query-block' while qemu is working on
> 'block-commit', it will cause memleaks, the memory leak stack is as
> follow:
> 
> Indirect leak of 12360 byte(s) in 3 object(s) allocated from:
>     #0 0x7f80f0b6d970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
>     #1 0x7f80ee86049d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
>     #2 0x55ea95b5bb67 in qdict_new /mnt/sdb/qemu-4.2.0-rc0/qobject/qdict.c:29
>     #3 0x55ea956cd043 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6427
>     #4 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
>     #5 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
>     #6 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
>     #7 0x55ea958818ea in bdrv_block_device_info /mnt/sdb/qemu-4.2.0-rc0/block/qapi.c:56
>     #8 0x55ea958879de in bdrv_query_info /mnt/sdb/qemu-4.2.0-rc0/block/qapi.c:392
>     #9 0x55ea9588b58f in qmp_query_block /mnt/sdb/qemu-4.2.0-rc0/block/qapi.c:578
>     #10 0x55ea95567392 in qmp_marshal_query_block qapi/qapi-commands-block-core.c:95
> 
> Indirect leak of 4120 byte(s) in 1 object(s) allocated from:
>     #0 0x7f80f0b6d970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
>     #1 0x7f80ee86049d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
>     #2 0x55ea95b5bb67 in qdict_new /mnt/sdb/qemu-4.2.0-rc0/qobject/qdict.c:29
>     #3 0x55ea956cd043 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6427
>     #4 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
>     #5 0x55ea956cc950 in bdrv_refresh_filename /mnt/sdb/qemu-4.2.0-rc0/block.c:6399
>     #6 0x55ea9569f301 in bdrv_backing_attach /mnt/sdb/qemu-4.2.0-rc0/block.c:1064
>     #7 0x55ea956a99dd in bdrv_replace_child_noperm /mnt/sdb/qemu-4.2.0-rc0/block.c:2283
>     #8 0x55ea956b9b53 in bdrv_replace_node /mnt/sdb/qemu-4.2.0-rc0/block.c:4196
>     #9 0x55ea956b9e49 in bdrv_append /mnt/sdb/qemu-4.2.0-rc0/block.c:4236
>     #10 0x55ea958c3472 in commit_start /mnt/sdb/qemu-4.2.0-rc0/block/commit.c:306
>     #11 0x55ea94b68ab0 in qmp_block_commit /mnt/sdb/qemu-4.2.0-rc0/blockdev.c:3459
>     #12 0x55ea9556a7a7 in qmp_marshal_block_commit qapi/qapi-commands-block-core.c:407
> 
> Fixes: bb808d5f5c0978828a974d547e6032402c339555
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
> ---
>  block.c | 1 +
>  1 file changed, 1 insertion(+)

Thanks, applied to my block branch:

https://git.xanclic.moe/XanClic/qemu/commits/branch/block

Max