5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jan Kara jack@suse.cz
[ Upstream commit 1a11201668e8635602577dcf06f2e96c591d8819 ]
Verify that number of partition maps isn't insanely high which can lead to large allocation in udf_sb_alloc_partition_maps(). All partition maps have to fit in the LVD which is in a single block.
Reported-by: syzbot+478f2c1a6f0f447a46bb@syzkaller.appspotmail.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Sasha Levin sashal@kernel.org --- fs/udf/super.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/fs/udf/super.c b/fs/udf/super.c index 9f2de5e7c6e1..361bc8acfb0f 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1417,7 +1417,7 @@ 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; + unsigned int table_len, part_map_count; int ret;
bh = udf_read_tagged(sb, block, block, &ident); @@ -1438,7 +1438,16 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block, "logical volume"); if (ret) goto out_bh; - ret = udf_sb_alloc_partition_maps(sb, le32_to_cpu(lvd->numPartitionMaps)); + + part_map_count = le32_to_cpu(lvd->numPartitionMaps); + if (part_map_count > table_len / sizeof(struct genericPartitionMap1)) { + udf_err(sb, "error loading logical volume descriptor: " + "Too many partition maps (%u > %u)\n", part_map_count, + table_len / (unsigned)sizeof(struct genericPartitionMap1)); + ret = -EIO; + goto out_bh; + } + ret = udf_sb_alloc_partition_maps(sb, part_map_count); if (ret) goto out_bh;