Commit 156ac944 authored by Paul Durrant's avatar Paul Durrant Committed by Anthony PERARD
Browse files

xen-block: stop leaking memory in xen_block_drive_create() 



The locally allocated QDict-s need to be freed. ('file_layer' will be
freed implicitly since it is added as an object to 'driver_layer').

Spotted by Coverity: CID 1398649

While in the neighbourhood free 'driver' and 'filename' as soon as they are
added to the QDicts. Freeing after the 'done' label doesn't make that much
sense as, if the error path jumps to that label, the values would be NULL
anyway.

This patch also makes that more obvious by taking the error path if
'params' is NULL and then asserting that both driver and filename are
non-NULL in the normal path.

Reported-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarPaul Durrant <paul.durrant@citrix.com>
Message-Id: <20190219163440.15702-1-paul.durrant@citrix.com>
Acked-by: default avatarAnthony PERARD <anthony.perard@citrix.com>
Signed-off-by: default avatarAnthony PERARD <anthony.perard@citrix.com>
parent 2ae23f0e

hw/block/xen-block.c

+9 −7
Original line number Diff line number Diff line
@@ -743,12 +743,12 @@ static XenBlockDrive *xen_block_drive_create(const char *id, 
        }



        g_strfreev(v);

    }



    if (!filename) {

        error_setg(errp, "no filename");

    } else {

        error_setg(errp, "no params");

        goto done;

    }



    assert(filename);

    assert(driver);



    drive = g_new0(XenBlockDrive, 1);
@@ -758,6 +758,7 @@ static XenBlockDrive *xen_block_drive_create(const char *id, 


    qdict_put_str(file_layer, "driver", "file");

    qdict_put_str(file_layer, "filename", filename);

    g_free(filename);



    if (mode && *mode != 'w') {

        qdict_put_bool(file_layer, "read-only", true);
@@ -793,16 +794,17 @@ static XenBlockDrive *xen_block_drive_create(const char *id, 
    driver_layer = qdict_new();



    qdict_put_str(driver_layer, "driver", driver);

    g_free(driver);



    qdict_put_obj(driver_layer, "file", QOBJECT(file_layer));



    g_assert(!drive->node_name);

    drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,

                                              &local_err);



done:

    g_free(driver);

    g_free(filename);

    qobject_unref(driver_layer);



done:

    if (local_err) {

        error_propagate(errp, local_err);

        xen_block_drive_destroy(drive, NULL);