libext2fs: fix potential integer overflow in bitmap accessors

bmap->cluster_bits has a maximum value of 19, but Coverity doesn't
know that.  To make it happy, and just in case there is a bug where
somehow the cluster size does get set to an invalid value and the rest
of the library doesn't check it, use 1ULL instead of 1 to avoid the
integer overflow.

Addresses-Coverity-Bug: 1500759
Addresses-Coverity-Bug: 1500764
Addresses-Coverity-Bug: 1500771
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/gen_bitmap64.c b/lib/ext2fs/gen_bitmap64.c
index d980908..c860c10 100644 (file)
--- a/lib/ext2fs/gen_bitmap64.c
+++ b/lib/ext2fs/gen_bitmap64.c
@@ -684,7 +684,7 @@ int ext2fs_test_block_bitmap_range2(ext2fs_block_bitmap gen_bmap,
 
        /* convert to clusters if necessary */
        block >>= bmap->cluster_bits;
-       end += (1 << bmap->cluster_bits) - 1;
+       end += (1ULL << bmap->cluster_bits) - 1;
        end >>= bmap->cluster_bits;
        num = end - block;
 
@@ -725,7 +725,7 @@ void ext2fs_mark_block_bitmap_range2(ext2fs_block_bitmap gen_bmap,
 
        /* convert to clusters if necessary */
        block >>= bmap->cluster_bits;
-       end += (1 << bmap->cluster_bits) - 1;
+       end += (1ULL << bmap->cluster_bits) - 1;
        end >>= bmap->cluster_bits;
        num = end - block;
 
@@ -766,7 +766,7 @@ void ext2fs_unmark_block_bitmap_range2(ext2fs_block_bitmap gen_bmap,
 
        /* convert to clusters if necessary */
        block >>= bmap->cluster_bits;
-       end += (1 << bmap->cluster_bits) - 1;
+       end += (1ULL << bmap->cluster_bits) - 1;
        end >>= bmap->cluster_bits;
        num = end - block;