From: Greg KH <gre...@linuxfoundation.org>

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jan Kara <j...@suse.cz>

commit adee11b2085bee90bd8f4f52123ffb07882d6256 upstream.

Check provided length of partition table so that (possibly maliciously)
corrupted partition table cannot cause accessing data beyond current buffer.

Signed-off-by: Jan Kara <j...@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/udf/super.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1254,6 +1254,7 @@ static int udf_load_logicalvol(struct su
        struct genericPartitionMap *gpm;
        uint16_t ident;
        struct buffer_head *bh;
+       unsigned int table_len;
        int ret = 0;
 
        bh = udf_read_tagged(sb, block, block, &ident);
@@ -1261,13 +1262,20 @@ static int udf_load_logicalvol(struct su
                return 1;
        BUG_ON(ident != TAG_IDENT_LVD);
        lvd = (struct logicalVolDesc *)bh->b_data;
+       table_len = le32_to_cpu(lvd->mapTableLength);
+       if (sizeof(*lvd) + table_len > sb->s_blocksize) {
+               udf_error(sb, __func__, "error loading logical volume 
descriptor: "
+                       "Partition table too long (%u > %lu)\n", table_len,
+                       sb->s_blocksize - sizeof(*lvd));
+               goto out_bh;
+       }
 
        ret = udf_sb_alloc_partition_maps(sb, 
le32_to_cpu(lvd->numPartitionMaps));
        if (ret)
                goto out_bh;
 
        for (i = 0, offset = 0;
-            i < sbi->s_partitions && offset < le32_to_cpu(lvd->mapTableLength);
+            i < sbi->s_partitions && offset < table_len;
             i++, offset += gpm->partitionMapLength) {
                struct udf_part_map *map = &sbi->s_partmaps[i];
                gpm = (struct genericPartitionMap *)


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