block: prevent an integer overflow in bvec_try_merge_hw_page

[platform/kernel/linux-rpi.git] / block / bio.c

diff --git a/block/bio.c b/block/bio.c
index 5eba53c..270f6b9 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -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);
 }