| Date | Tue, 02 Oct 2012 00:53:29 +0200 | From | Willy Tarreau <> | Subject | [ 092/180] udf: Avoid run away loop when partition table length is corrupted |
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2.6.32-longterm review patch. If anyone has any objections, please let me know.
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From: Jan Kara <jack@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 <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu> --- fs/udf/super.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletions(-)
diff --git a/fs/udf/super.c b/fs/udf/super.c index ee6b3af..0388d43 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1249,6 +1249,7 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block, 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); @@ -1257,6 +1258,14 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block, 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; + } + i = udf_sb_alloc_partition_maps(sb, le32_to_cpu(lvd->numPartitionMaps)); if (i != 0) { ret = i; @@ -1264,7 +1273,7 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block, } 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 *) -- 1.7.2.1.45.g54fbc
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