blkdebug: Catch bs->exact_filename overflow

The bs->exact_filename field may not be sufficient to store the full
blkdebug node filename. In this case, we should not generate a filename
at all instead of an unusable one.

Cc: qemu-stable@nongnu.org
Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170613172006.19685-2-mreitz@redhat.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
stable-2.10
Max Reitz 2017-06-13 19:20:05 +02:00
parent 4172a00373
commit de81d72d3d
1 changed files with 7 additions and 3 deletions

View File

@ -839,9 +839,13 @@ static void blkdebug_refresh_filename(BlockDriverState *bs, QDict *options)
}
if (!force_json && bs->file->bs->exact_filename[0]) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"blkdebug:%s:%s", s->config_file ?: "",
bs->file->bs->exact_filename);
int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"blkdebug:%s:%s", s->config_file ?: "",
bs->file->bs->exact_filename);
if (ret >= sizeof(bs->exact_filename)) {
/* An overflow makes the filename unusable, so do not report any */
bs->exact_filename[0] = 0;
}
}
opts = qdict_new();