Check device size on mount.

[android-x86/external-exfat.git] / libexfat / mount.c

diff --git a/libexfat/mount.c b/libexfat/mount.c
index 3606ad6..70c8af5 100644 (file)
--- a/libexfat/mount.c
+++ b/libexfat/mount.c
@@ -24,6 +24,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <inttypes.h>
 #include <unistd.h>
 #include <sys/types.h>
 
@@ -207,8 +208,27 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
                exfat_error("exFAT file system is not found");
                return -EIO;
        }
+       ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
+       if (ef->zero_cluster == NULL)
+       {
+               exfat_close(ef->dev);
+               free(ef->sb);
+               exfat_error("failed to allocate zero sector");
+               return -ENOMEM;
+       }
+       /* use zero_cluster as a temporary buffer for VBR checksum verification */
+       if (verify_vbr_checksum(ef->dev, ef->zero_cluster,
+                       SECTOR_SIZE(*ef->sb)) != 0)
+       {
+               free(ef->zero_cluster);
+               exfat_close(ef->dev);
+               free(ef->sb);
+               return -EIO;
+       }
+       memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));
        if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
        {
+               free(ef->zero_cluster);
                exfat_close(ef->dev);
                exfat_error("unsupported exFAT version: %hhu.%hhu",
                                ef->sb->version.major, ef->sb->version.minor);
@@ -217,6 +237,7 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
        }
        if (ef->sb->fat_count != 1)
        {
+               free(ef->zero_cluster);
                exfat_close(ef->dev);
                exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
                free(ef->sb);
@@ -225,31 +246,25 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
        /* officially exFAT supports cluster size up to 32 MB */
        if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
        {
+               free(ef->zero_cluster);
                exfat_close(ef->dev);
                exfat_error("too big cluster size: 2^%d",
                                (int) ef->sb->sector_bits + (int) ef->sb->spc_bits);
                free(ef->sb);
                return -EIO;
        }
-
-       ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
-       if (ef->zero_cluster == NULL)
-       {
-               exfat_close(ef->dev);
-               free(ef->sb);
-               exfat_error("failed to allocate zero sector");
-               return -ENOMEM;
-       }
-       /* use zero_cluster as a temporary buffer for VBR checksum verification */
-       if (verify_vbr_checksum(ef->dev, ef->zero_cluster,
-                       SECTOR_SIZE(*ef->sb)) != 0)
+       if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
+                       exfat_get_size(ef->dev))
        {
                free(ef->zero_cluster);
+               exfat_error("file system is larger than underlying device: "
+                               "%"PRIu64" > %"PRIu64,
+                               le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb),
+                               exfat_get_size(ef->dev));
                exfat_close(ef->dev);
                free(ef->sb);
                return -EIO;
        }
-       memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));
 
        ef->root = malloc(sizeof(struct exfat_node));
        if (ef->root == NULL)