From cb14d340ef1737c24125dd663eff77734a482d47 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 27 Jun 2012 20:08:44 +0200 Subject: udf: Use 'ret' instead of abusing 'i' in udf_load_logicalvol() Signed-off-by: Jan Kara --- fs/udf/super.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/fs/udf/super.c b/fs/udf/super.c index ac8a348dcb69..9da6f4ee112c 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1233,11 +1233,9 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block, BUG_ON(ident != TAG_IDENT_LVD); lvd = (struct logicalVolDesc *)bh->b_data; - i = udf_sb_alloc_partition_maps(sb, le32_to_cpu(lvd->numPartitionMaps)); - if (i != 0) { - ret = i; + 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); -- cgit v1.2.3-58-ga151 From adee11b2085bee90bd8f4f52123ffb07882d6256 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 27 Jun 2012 20:20:22 +0200 Subject: udf: Avoid run away loop when partition table length is corrupted 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 --- fs/udf/super.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/udf/super.c b/fs/udf/super.c index 9da6f4ee112c..ce911f50b39d 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1225,6 +1225,7 @@ 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); @@ -1232,13 +1233,20 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block, 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_err(sb, "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 *) -- cgit v1.2.3-58-ga151 From 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 27 Jun 2012 21:23:07 +0200 Subject: udf: Fortify loading of sparing table Add sanity checks when loading sparing table from disk to avoid accessing unallocated memory or writing to it. Signed-off-by: Jan Kara --- fs/udf/super.c | 86 ++++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 53 insertions(+), 33 deletions(-) diff --git a/fs/udf/super.c b/fs/udf/super.c index ce911f50b39d..8d86a8706c0e 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -56,6 +56,7 @@ #include #include #include +#include #include #include "udf_sb.h" @@ -1215,11 +1216,59 @@ out_bh: return ret; } +static int udf_load_sparable_map(struct super_block *sb, + struct udf_part_map *map, + struct sparablePartitionMap *spm) +{ + uint32_t loc; + uint16_t ident; + struct sparingTable *st; + struct udf_sparing_data *sdata = &map->s_type_specific.s_sparing; + int i; + struct buffer_head *bh; + + map->s_partition_type = UDF_SPARABLE_MAP15; + sdata->s_packet_len = le16_to_cpu(spm->packetLength); + if (!is_power_of_2(sdata->s_packet_len)) { + udf_err(sb, "error loading logical volume descriptor: " + "Invalid packet length %u\n", + (unsigned)sdata->s_packet_len); + return -EIO; + } + if (spm->numSparingTables > 4) { + udf_err(sb, "error loading logical volume descriptor: " + "Too many sparing tables (%d)\n", + (int)spm->numSparingTables); + return -EIO; + } + + for (i = 0; i < spm->numSparingTables; i++) { + loc = le32_to_cpu(spm->locSparingTable[i]); + bh = udf_read_tagged(sb, loc, loc, &ident); + if (!bh) + continue; + + st = (struct sparingTable *)bh->b_data; + if (ident != 0 || + strncmp(st->sparingIdent.ident, UDF_ID_SPARING, + strlen(UDF_ID_SPARING)) || + sizeof(*st) + le16_to_cpu(st->reallocationTableLen) > + sb->s_blocksize) { + brelse(bh); + continue; + } + + sdata->s_spar_map[i] = bh; + } + map->s_partition_func = udf_get_pblock_spar15; + return 0; +} + static int udf_load_logicalvol(struct super_block *sb, sector_t block, struct kernel_lb_addr *fileset) { struct logicalVolDesc *lvd; - int i, j, offset; + int i, offset; uint8_t type; struct udf_sb_info *sbi = UDF_SB(sb); struct genericPartitionMap *gpm; @@ -1281,38 +1330,9 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block, } else if (!strncmp(upm2->partIdent.ident, UDF_ID_SPARABLE, strlen(UDF_ID_SPARABLE))) { - uint32_t loc; - struct sparingTable *st; - struct sparablePartitionMap *spm = - (struct sparablePartitionMap *)gpm; - - map->s_partition_type = UDF_SPARABLE_MAP15; - map->s_type_specific.s_sparing.s_packet_len = - le16_to_cpu(spm->packetLength); - for (j = 0; j < spm->numSparingTables; j++) { - struct buffer_head *bh2; - - loc = le32_to_cpu( - spm->locSparingTable[j]); - bh2 = udf_read_tagged(sb, loc, loc, - &ident); - map->s_type_specific.s_sparing. - s_spar_map[j] = bh2; - - if (bh2 == NULL) - continue; - - st = (struct sparingTable *)bh2->b_data; - if (ident != 0 || strncmp( - st->sparingIdent.ident, - UDF_ID_SPARING, - strlen(UDF_ID_SPARING))) { - brelse(bh2); - map->s_type_specific.s_sparing. - s_spar_map[j] = NULL; - } - } - map->s_partition_func = udf_get_pblock_spar15; + if (udf_load_sparable_map(sb, map, + (struct sparablePartitionMap *)gpm) < 0) + goto out_bh; } else if (!strncmp(upm2->partIdent.ident, UDF_ID_METADATA, strlen(UDF_ID_METADATA))) { -- cgit v1.2.3-58-ga151