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) { + g_free(s->x_dirty_bitmap); + } +} + /* * 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