f2fs crypto: add missing locking for keyring_key access

This patch adopts:
	ext4 crypto: add missing locking for keyring_key access

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/crypto_key.c b/fs/f2fs/crypto_key.c
index 2d491ee..9094fca 100644 (file)
--- a/fs/f2fs/crypto_key.c
+++ b/fs/f2fs/crypto_key.c
@@ -202,9 +202,11 @@ retry:
                res = -ENOKEY;
                goto out;
        }
+       down_read(&keyring_key->sem);
        ukp = user_key_payload(keyring_key);
        if (ukp->datalen != sizeof(struct f2fs_encryption_key)) {
                res = -EINVAL;
+               up_read(&keyring_key->sem);
                goto out;
        }
        master_key = (struct f2fs_encryption_key *)ukp->data;
@@ -215,10 +217,12 @@ retry:
                                "f2fs: key size incorrect: %d\n",
                                master_key->size);
                res = -ENOKEY;
+               up_read(&keyring_key->sem);
                goto out;
        }
        res = f2fs_derive_key_aes(ctx.nonce, master_key->raw,
                                  raw_key);
+       up_read(&keyring_key->sem);
        if (res)
                goto out;