1 files changed, 20 insertions, 37 deletions

diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c
index 47324062fee5..66b9c9150fed 100644
--- a/fs/crypto/inline_crypt.c
+++ b/fs/crypto/inline_crypt.c
@@ -22,22 +22,14 @@
 
 #include "fscrypt_private.h"
 
-static struct block_device **fscrypt_get_devices(struct super_block *sb,
-						 unsigned int *num_devs)
+static unsigned int
+fscrypt_get_devices(struct super_block *sb,
+		    struct block_device *devs[FSCRYPT_MAX_DEVICES])
 {
-	struct block_device **devs;
-
-	if (sb->s_cop->get_devices) {
-		devs = sb->s_cop->get_devices(sb, num_devs);
-		if (devs)
-			return devs;
-	}
-	devs = kmalloc_obj(*devs);
-	if (!devs)
-		return ERR_PTR(-ENOMEM);
+	if (sb->s_cop->get_devices)
+		return sb->s_cop->get_devices(sb, devs);
 	devs[0] = sb->s_bdev;
-	*num_devs = 1;
-	return devs;
+	return 1;
 }
 
 static unsigned int fscrypt_get_dun_bytes(const struct fscrypt_inode_info *ci)
@@ -96,7 +88,7 @@ int fscrypt_select_encryption_impl(struct fscrypt_inode_info *ci,
 	const struct inode *inode = ci->ci_inode;
 	struct super_block *sb = inode->i_sb;
 	struct blk_crypto_config crypto_cfg;
-	struct block_device **devs;
+	struct block_device *devs[FSCRYPT_MAX_DEVICES];
 	unsigned int num_devs;
 	unsigned int i;
 
@@ -135,20 +127,15 @@ int fscrypt_select_encryption_impl(struct fscrypt_inode_info *ci,
 	crypto_cfg.key_type = is_hw_wrapped_key ?
 		BLK_CRYPTO_KEY_TYPE_HW_WRAPPED : BLK_CRYPTO_KEY_TYPE_RAW;
 
-	devs = fscrypt_get_devices(sb, &num_devs);
-	if (IS_ERR(devs))
-		return PTR_ERR(devs);
-
+	num_devs = fscrypt_get_devices(sb, devs);
 	for (i = 0; i < num_devs; i++) {
 		if (!blk_crypto_config_supported(devs[i], &crypto_cfg))
-			goto out_free_devs;
+			return 0;
 	}
 
 	fscrypt_log_blk_crypto_impl(ci->ci_mode, devs, num_devs, &crypto_cfg);
 
 	ci->ci_inlinecrypt = true;
-out_free_devs:
-	kfree(devs);
 
 	return 0;
 }
@@ -164,7 +151,7 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
 	enum blk_crypto_key_type key_type = is_hw_wrapped ?
 		BLK_CRYPTO_KEY_TYPE_HW_WRAPPED : BLK_CRYPTO_KEY_TYPE_RAW;
 	struct blk_crypto_key *blk_key;
-	struct block_device **devs;
+	struct block_device *devs[FSCRYPT_MAX_DEVICES];
 	unsigned int num_devs;
 	unsigned int i;
 	int err;
@@ -182,17 +169,12 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
 	}
 
 	/* Start using blk-crypto on all the filesystem's block devices. */
-	devs = fscrypt_get_devices(sb, &num_devs);
-	if (IS_ERR(devs)) {
-		err = PTR_ERR(devs);
-		goto fail;
-	}
+	num_devs = fscrypt_get_devices(sb, devs);
 	for (i = 0; i < num_devs; i++) {
 		err = blk_crypto_start_using_key(devs[i], blk_key);
 		if (err)
 			break;
 	}
-	kfree(devs);
 	if (err) {
 		fscrypt_err(inode, "error %d starting to use blk-crypto", err);
 		goto fail;
@@ -210,20 +192,21 @@ void fscrypt_destroy_inline_crypt_key(struct super_block *sb,
 				      struct fscrypt_prepared_key *prep_key)
 {
 	struct blk_crypto_key *blk_key = prep_key->blk_key;
-	struct block_device **devs;
+	struct block_device *devs[FSCRYPT_MAX_DEVICES];
 	unsigned int num_devs;
 	unsigned int i;
 
 	if (!blk_key)
 		return;
 
-	/* Evict the key from all the filesystem's block devices. */
-	devs = fscrypt_get_devices(sb, &num_devs);
-	if (!IS_ERR(devs)) {
-		for (i = 0; i < num_devs; i++)
-			blk_crypto_evict_key(devs[i], blk_key);
-		kfree(devs);
-	}
+	/*
+	 * Evict the key from all the filesystem's block devices.
+	 * This *must* be done before the key is freed.
+	 */
+	num_devs = fscrypt_get_devices(sb, devs);
+	for (i = 0; i < num_devs; i++)
+		blk_crypto_evict_key(devs[i], blk_key);
+
 	kfree_sensitive(blk_key);
 }