libblkid: bcache: add missing NULL check

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

diff --git a/libblkid/src/superblocks/bcache.c b/libblkid/src/superblocks/bcache.c
index 08be01363e014d8bb0f8330b88ed9acac7ab5cf5..f9e0a9908f729846740d7ac353113fc9a041c837 100644 (file)
--- a/libblkid/src/superblocks/bcache.c
+++ b/libblkid/src/superblocks/bcache.c
@@ -216,6 +216,8 @@ static int bcache_verify_checksum(blkid_probe pr, const struct blkid_idmag *mag,
        csummed_size = offsetof(__typeof__(*bcs), d) +
                sizeof(bcs->d[0]) * le16_to_cpu(bcs->keys);
        csummed = blkid_probe_get_sb_buffer(pr, mag, csummed_size);
+       if (!csummed)
+               return 0;
        csum = ul_crc64_we(csummed + BCACHE_SB_CSUMMED_START,
                           csummed_size - BCACHE_SB_CSUMMED_START);
        return blkid_probe_verify_csum(pr, csum, le64_to_cpu(bcs->csum));