Add d/patches/check-sector-and-cluster-size. Fix for

[sven/exfat-utils.git] / debian / patches / check-sector-and-cluster-size

diff --git a/debian/patches/check-sector-and-cluster-size b/debian/patches/check-sector-and-cluster-size
new file mode 100644 (file)
index 0000000..c630c2d
--- /dev/null
+++ b/debian/patches/check-sector-and-cluster-size
@@ -0,0 +1,49 @@
+Patch for https://github.com/relan/exfat/issues/5
+See also:
+https://blog.fuzzing-project.org/25-Heap-overflow-and-endless-loop-in-exfatfsck-exfat-utils.html
+Index: exfat-utils/libexfat/mount.c
+===================================================================
+--- exfat-utils.orig/libexfat/mount.c
++++ exfat-utils/libexfat/mount.c
+@@ -172,6 +172,24 @@ int exfat_mount(struct exfat* ef, const
+               exfat_error("exFAT file system is not found");
+               return -EIO;
+       }
++      /* sector cannot be smaller than 512 bytes */
++        if (ef->sb->sector_bits < 9)
++        {
++                exfat_close(ef->dev);
++                exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits);
++                free(ef->sb);
++                return -EIO;
++        }
++        /* officially exFAT supports cluster size up to 32 MB */
++        if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
++        {
++                exfat_close(ef->dev);
++                exfat_error("too big cluster size: 2^(%hhd+%hhd)",
++                                ef->sb->sector_bits, ef->sb->spc_bits);
++                free(ef->sb);
++                return -EIO;
++        }
++
+       if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
+       {
+               exfat_close(ef->dev);
+@@ -187,16 +205,6 @@ int exfat_mount(struct exfat* ef, const
+               exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
+               return -EIO;
+       }
+-      /* officially exFAT supports cluster size up to 32 MB */
+-      if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
+-      {
+-              exfat_close(ef->dev);
+-              free(ef->sb);
+-              exfat_error("too big cluster size: 2^%d",
+-                              (int) ef->sb->sector_bits + (int) ef->sb->spc_bits);
+-              return -EIO;
+-      }
+-
+       ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
+       if (ef->zero_cluster == NULL)
+       {