power: supply: ltc2941-battery-gauge: fix use-after-free

[sagit-ice-cold/kernel_xiaomi_msm8998.git] / block / bio.c

diff --git a/block/bio.c b/block/bio.c
index 68bbc83..cf513f7 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -1216,8 +1216,11 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
                        }
                }
 
-               if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes)
+               if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) {
+                       if (!map_data)
+                               __free_page(page);
                        break;
+               }
 
                len -= bytes;
                offset = 0;
@@ -1268,6 +1271,7 @@ 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;
@@ -1312,7 +1316,12 @@ 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;
                }
@@ -1374,10 +1383,8 @@ 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;
-               page_cache_release(pages[j]);
+       bio_for_each_segment_all(bvec, bio, j) {
+               put_page(bvec->bv_page);
        }
  out:
        kfree(pages);