From 21827917342bac938e462513afee6c7d39f28adc Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Tue, 13 Jun 2017 19:20:06 +0200 Subject: [PATCH] blkverify: Catch bs->exact_filename overflow The bs->exact_filename field may not be sufficient to store the full blkverify 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 Signed-off-by: Max Reitz Message-id: 20170613172006.19685-3-mreitz@redhat.com Reviewed-by: Alberto Garcia Reviewed-by: Stefan Hajnoczi Signed-off-by: Max Reitz (cherry picked from commit 05cc758a3dfc79488d0a8eb7f5830a41871e78d0) Signed-off-by: Michael Roth --- block/blkverify.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/block/blkverify.c b/block/blkverify.c index 6b0a603cf0..06369f9eac 100644 --- a/block/blkverify.c +++ b/block/blkverify.c @@ -301,10 +301,14 @@ static void blkverify_refresh_filename(BlockDriverState *bs, QDict *options) if (bs->file->bs->exact_filename[0] && s->test_file->bs->exact_filename[0]) { - snprintf(bs->exact_filename, sizeof(bs->exact_filename), - "blkverify:%s:%s", - bs->file->bs->exact_filename, - s->test_file->bs->exact_filename); + int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename), + "blkverify:%s:%s", + bs->file->bs->exact_filename, + s->test_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; + } } } -- 2.39.2