diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2014-06-30 19:03:37 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-07-01 10:15:34 +0200 |
| commit | 6764579f894950afe87d8ec3b323adde8925d4fd (patch) | |
| tree | bfa56bfa82c72c4fd5252f4950f578117835e3e6 | |
| parent | 4caf0fcd45db46920a6264b1621ae6adc772ef19 (diff) | |
block/cow: Avoid use of uninitialized cow_bs in error path
Commit 25814e8987 introduced an error-exit code path which does
a "goto exit" before the cow_bs variable is initialized, meaning
we would call bdrv_unref() on an uninitialized variable and
likely segfault. Fix this by moving the NULL-initialization
to the top of the function and making the exit code path handle
the case where it is NULL.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
| -rw-r--r-- | block/cow.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/block/cow.c b/block/cow.c index 8f81ee6d56..6ee483327f 100644 --- a/block/cow.c +++ b/block/cow.c @@ -332,7 +332,7 @@ static int cow_create(const char *filename, QemuOpts *opts, Error **errp) char *image_filename = NULL; Error *local_err = NULL; int ret; - BlockDriverState *cow_bs; + BlockDriverState *cow_bs = NULL; /* Read out options */ image_sectors = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0) / 512; @@ -344,7 +344,6 @@ static int cow_create(const char *filename, QemuOpts *opts, Error **errp) goto exit; } - cow_bs = NULL; ret = bdrv_open(&cow_bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err); if (ret < 0) { @@ -383,7 +382,9 @@ static int cow_create(const char *filename, QemuOpts *opts, Error **errp) exit: g_free(image_filename); - bdrv_unref(cow_bs); + if (cow_bs) { + bdrv_unref(cow_bs); + } return ret; } |