From 69ecbbedac8e353bbd924fad16fed0c7c54e6382 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 15 Mar 2010 11:21:13 +0300 Subject: udf: potential integer overflow bloc->logicalBlockNum is unsigned so it's never less than zero. When I saw that, it made me worry that "bloc->logicalBlockNum + count" could overflow. That's why I changed the check for less than zero to an overflow check. (The test works because "count" is also unsigned.) Signed-off-by: Dan Carpenter Signed-off-by: Jan Kara --- fs/udf/balloc.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/fs/udf/balloc.c b/fs/udf/balloc.c index 19626e2491c..9a9378b4eb5 100644 --- a/fs/udf/balloc.c +++ b/fs/udf/balloc.c @@ -125,9 +125,8 @@ static void udf_bitmap_free_blocks(struct super_block *sb, mutex_lock(&sbi->s_alloc_mutex); partmap = &sbi->s_partmaps[bloc->partitionReferenceNum]; - if (bloc->logicalBlockNum < 0 || - (bloc->logicalBlockNum + count) > - partmap->s_partition_len) { + if (bloc->logicalBlockNum + count < count || + (bloc->logicalBlockNum + count) > partmap->s_partition_len) { udf_debug("%d < %d || %d + %d > %d\n", bloc->logicalBlockNum, 0, bloc->logicalBlockNum, count, partmap->s_partition_len); @@ -393,9 +392,8 @@ static void udf_table_free_blocks(struct super_block *sb, mutex_lock(&sbi->s_alloc_mutex); partmap = &sbi->s_partmaps[bloc->partitionReferenceNum]; - if (bloc->logicalBlockNum < 0 || - (bloc->logicalBlockNum + count) > - partmap->s_partition_len) { + if (bloc->logicalBlockNum + count < count || + (bloc->logicalBlockNum + count) > partmap->s_partition_len) { udf_debug("%d < %d || %d + %d > %d\n", bloc->logicalBlockNum, 0, bloc->logicalBlockNum, count, partmap->s_partition_len); -- cgit v1.2.3