more bio_map_user_iov() leak fixes

[mirror_ubuntu-artful-kernel.git] / block / bio.c

diff --git a/block/bio.c b/block/bio.c
index 9a63597aaaccd226dc03b9ab3595c693d5a918d7..a49d8e77d7507ec48d22bf2fcf60ac04cd21b7a3 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -1327,6 +1327,7 @@ struct bio *bio_map_user_iov(struct request_queue *q,
        int ret, offset;
        struct iov_iter i;
        struct iovec iov;
+       struct bio_vec *bvec;
 
        iov_for_each(iov, i, *iter) {
                unsigned long uaddr = (unsigned long) iov.iov_base;
@@ -1371,7 +1372,12 @@ struct bio *bio_map_user_iov(struct request_queue *q,
                ret = get_user_pages_fast(uaddr, local_nr_pages,
                                (iter->type & WRITE) != WRITE,
                                &pages[cur_page]);
-               if (ret < local_nr_pages) {
+               if (unlikely(ret < local_nr_pages)) {
+                       for (j = cur_page; j < page_limit; j++) {
+                               if (!pages[j])
+                                       break;
+                               put_page(pages[j]);
+                       }
                        ret = -EFAULT;
                        goto out_unmap;
                }
@@ -1379,6 +1385,7 @@ struct bio *bio_map_user_iov(struct request_queue *q,
                offset = offset_in_page(uaddr);
                for (j = cur_page; j < page_limit; j++) {
                        unsigned int bytes = PAGE_SIZE - offset;
+                       unsigned short prev_bi_vcnt = bio->bi_vcnt;
 
                        if (len <= 0)
                                break;
@@ -1393,6 +1400,13 @@ struct bio *bio_map_user_iov(struct request_queue *q,
                                            bytes)
                                break;
 
+                       /*
+                        * check if vector was merged with previous
+                        * drop page reference if needed
+                        */
+                       if (bio->bi_vcnt == prev_bi_vcnt)
+                               put_page(pages[j]);
+
                        len -= bytes;
                        offset = 0;
                }
@@ -1419,10 +1433,8 @@ struct bio *bio_map_user_iov(struct request_queue *q,
        return bio;
 
  out_unmap:
-       for (j = 0; j < nr_pages; j++) {
-               if (!pages[j])
-                       break;
-               put_page(pages[j]);
+       bio_for_each_segment_all(bvec, bio, j) {
+               put_page(bvec->bv_page);
        }
  out:
        kfree(pages);