libblkid: more robust idx usage [coverity scan]

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libblkid/src/superblocks/superblocks.c b/libblkid/src/superblocks/superblocks.c
index e465eb154e927d6155332c292bef4d3d80b1a414..d985adc05a9a1aa416152ac295a31ae449049d39 100644 (file)
--- a/libblkid/src/superblocks/superblocks.c
+++ b/libblkid/src/superblocks/superblocks.c
@@ -440,10 +440,12 @@ static int superblocks_safeprobe(blkid_probe pr, struct blkid_chain *chn)
 
                count++;
 
-               if (idinfos[chn->idx]->usage & (BLKID_USAGE_RAID | BLKID_USAGE_CRYPTO))
+               if (chn->idx >= 0 &&
+                   idinfos[chn->idx]->usage & (BLKID_USAGE_RAID | BLKID_USAGE_CRYPTO))
                        break;
 
-               if (!(idinfos[chn->idx]->flags & BLKID_IDINFO_TOLERANT))
+               if (chn->idx >= 0 &&
+                   !(idinfos[chn->idx]->flags & BLKID_IDINFO_TOLERANT))
                        intol++;
 
                if (count == 1) {