btrfs/raid56: fix and cleanup some error paths

The alloc_rbio() frees "raid_map" and "bbio" on error, so there is a
potential double free bug in raid56_parity_write().  The
raid56_parity_write() and raid56_parity_recover() functions should still
free "raid_map" and "bbio" on error if other errors occur though, so I
have added some more calls to kfree().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 0525e1389f5b..0db856ceecc4 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1687,11 +1687,8 @@ int raid56_parity_write(struct btrfs_root *root, struct bio *bio,
         struct blk_plug_cb *cb;
 
         rbio = alloc_rbio(root, bbio, raid_map, stripe_len);
-        if (IS_ERR(rbio)) {
-                kfree(raid_map);
-                kfree(bbio);
+        if (IS_ERR(rbio))
                 return PTR_ERR(rbio);
-        }
         bio_list_add(&rbio->bio_list, bio);
         rbio->bio_list_bytes = bio->bi_size;
 
@@ -2041,9 +2038,8 @@ int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
         int ret;
 
         rbio = alloc_rbio(root, bbio, raid_map, stripe_len);
-        if (IS_ERR(rbio)) {
+        if (IS_ERR(rbio))
                 return PTR_ERR(rbio);
-        }
 
         rbio->read_rebuild = 1;
         bio_list_add(&rbio->bio_list, bio);
@@ -2052,6 +2048,8 @@ int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
         rbio->faila = find_logical_bio_stripe(rbio, bio);
         if (rbio->faila == -1) {
                 BUG();
+                kfree(raid_map);
+                kfree(bbio);
                 kfree(rbio);
                 return -EIO;
         }