When using a non-UTF8 secret to create a volume using qemu-img, the
following error happens:
$ qemu-img create -f luks --object
secret,id=vol_1_encrypt0,file=vol_resize_pool.vol_1.secret.qzVQrI -o
key-secret=vol_1_encrypt0 /var/tmp/pool_target/vol_1 10240K
Formatting '/var/tmp/pool_target/vol_1', fmt=luks size=10485760
key-secret=vol_1_encrypt0
qemu-img: /var/tmp/pool_target/vol_1: Data from secret vol_1_encrypt0 is not
valid UTF-8
However, the created file '/var/tmp/pool_target/vol_1' is left behind in the
file system after the failure. This behavior can be observed when creating
the volume using Libvirt, via 'virsh vol-create', and then getting "volume
target path already exist" errors when trying to re-create the volume.
The volume file is created inside block_crypto_co_create_opts_luks(), in
block/crypto.c. If the bdrv_create_file() call is successful but any
succeeding step fails*, the existing 'fail' label does not take into
account the created file, leaving it behind.
This patch changes block_crypto_co_create_opts_luks() to delete
'filename' in case of failure. A failure in this point means that
the volume is now truncated/corrupted, so even if 'filename' was an
existing volume before calling qemu-img, it is now unusable. Deleting
the file it is not much worse than leaving it in the filesystem in
this scenario, and we don't have to deal with checking the file
pre-existence in the code.
* in our case, block_crypto_co_create_generic calls qcrypto_block_create,
which calls qcrypto_block_luks_create, and this function fails when
calling qcrypto_secret_lookup_as_utf8.
Reported-by: Srikanth Aithal <bssrika...@in.ibm.com>
Suggested-by: Kevin Wolf <kw...@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com>
---
block/crypto.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/block/crypto.c b/block/crypto.c
index 7eb698774e..fe2f0c42b0 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -30,6 +30,7 @@
#include "qapi/error.h"
#include "qemu/module.h"
#include "qemu/option.h"
+#include "qemu/cutils.h"
#include "crypto.h"
typedef struct BlockCrypto BlockCrypto;
@@ -599,6 +600,27 @@ fail:
bdrv_unref(bs);
qapi_free_QCryptoBlockCreateOptions(create_opts);
qobject_unref(cryptoopts);
+
+ /*
+ * If an error occurred, delete the file. Even if the file existed
+ * beforehand, it has been truncated and corrupted in the process.
+ */
+ if (ret) {
+ Error *local_err;
+ int r_del = bdrv_delete_file(filename, &local_err);
+ /*
+ * ENOTSUP will happen if the block driver doesn't support
+ * 'bdrv_co_delete_file'. ENOENT will be fired by
+ * 'raw_co_delete_file' if the file doesn't exist. Both are
+ * predictable (we're not verifying if the driver supports
+ * file deletion or if the file was created), thus we
+ * shouldn't report this back to the user.
+ */
+ if ((r_del < 0) && (r_del != -ENOTSUP) && (r_del != -ENOENT)) {
+ error_reportf_err(local_err, "%s: ", bs->filename);
+ }
+ }
+
return ret;
}
--
2.21.0
