[patch] btrfs/raid56: fix and cleanup some error paths

Dan Carpenter
2013-07-22T06:55:15Z

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>

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 0525e13..0db856c 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;
}