executor: fix syz_mount_image

1. It always crashed in cover_reset when coverage is disabled.
2. Use NONFAILING when accessing image segments.
3. Give it additional 100 ms as it may be slow.
4. Add a test for syz_mount_image.

1 files changed, 7 insertions, 1 deletions

diff --git a/executor/executor_linux.h b/executor/executor_linux.h
index 13d6a598e..73005877d 100644
--- a/executor/executor_linux.h
+++ b/executor/executor_linux.h
@@ -139,8 +139,14 @@ static void cover_enable(cover_t* cov, bool collect_comps, bool extra)
 
 static void cover_reset(cover_t* cov)
 {
-	if (cov == 0)
+	// Callers in common_linux.h don't check this flag.
+	if (!flag_coverage)
+		return;
+	if (cov == 0) {
+		if (current_cover == 0)
+			fail("cover_reset: current_cover == 0");
 		cov = current_cover;
+	}
 	*(uint64*)cov->data = 0;
 }