blkid: Avoid division by zero error when probing an invalid FAT filesystem

Addresses-Sourceforge-Bug: #1831627

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/blkid/probe.c b/lib/blkid/probe.c
index a188d82..4c72a56 100644 (file)
--- a/lib/blkid/probe.c
+++ b/lib/blkid/probe.c
@@ -284,6 +284,8 @@ static int probe_fat(struct blkid_probe *probe,
                        (sector_size-1)) / sector_size;
 
        cluster_count = sect_count - (reserved + fat_size + dir_size);
+       if (ms->ms_cluster_size == 0)
+               return 1;
        cluster_count /= ms->ms_cluster_size;
 
        if (cluster_count > FAT32_MAX)