[PATCH v2 1/3] block: fix arg type of bio_trim()

[Naohiro Aota <naohiro.aota@wdc.com>]

From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

The function bio_trim has offset and size arguments that are declared
as int.

The callers of this function uses sector_t type when passing the offset
and size e,g. drivers/md/raid1.c:narrow_write_error() and
drivers/md/raid1.c:narrow_write_error().

Change offset and size arguments to sector_t type for bio_trim(). Also, add
WARN_ON() to catch their overflow.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 block/bio.c         | 14 +++++++++++---
 include/linux/bio.h |  2 +-
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 44205dfb6b60..69a9751b18e7 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1465,12 +1465,20 @@ EXPORT_SYMBOL(bio_split);
  * @offset:	number of sectors to trim from the front of @bio
  * @size:	size we want to trim @bio to, in sectors
  */
-void bio_trim(struct bio *bio, int offset, int size)
+void bio_trim(struct bio *bio, sector_t offset, sector_t size)
 {
-	/* 'bio' is a cloned bio which we need to trim to match
-	 * the given offset and size.
+	const sector_t uint_max_sectors = UINT_MAX >> SECTOR_SHIFT;
+
+	/*
+	 * 'bio' is a cloned bio which we need to trim to match the given
+	 * offset and size.
 	 */
 
+	/* sanity check */
+	if (WARN_ON(offset > uint_max_sectors || size > uint_max_sectors ||
+		    offset + size > bio->bi_iter.bi_size))
+		return;
+
 	size <<= 9;
 	if (offset == 0 && size == bio->bi_iter.bi_size)
 		return;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index a0b4cfdf62a4..c91bc70add06 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -379,7 +379,7 @@ static inline void bip_set_seed(struct bio_integrity_payload *bip,
 
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
-extern void bio_trim(struct bio *bio, int offset, int size);
+extern void bio_trim(struct bio *bio, sector_t offset, sector_t size);
 extern struct bio *bio_split(struct bio *bio, int sectors,
 			     gfp_t gfp, struct bio_set *bs);
 
-- 
2.32.0