block: prevent an integer overflow in bvec_try_merge_hw_page

Reordered a check to avoid a possible overflow when adding len to bv_len.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20231204173419.782378-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2023-12-04 18:34:18 +01:00 committed by Jens Axboe
parent f19d1e3b17
commit 3f034c374a

View File

@ -944,7 +944,7 @@ bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv,
if ((addr1 | mask) != (addr2 | mask))
return false;
if (bv->bv_len + len > queue_max_segment_size(q))
if (len > queue_max_segment_size(q) - bv->bv_len)
return false;
return bvec_try_merge_page(bv, page, len, offset, same_page);
}