diff options
Diffstat (limited to 'fs/crypto/keysetup.c')
| -rw-r--r-- | fs/crypto/keysetup.c | 44 |
1 files changed, 29 insertions, 15 deletions
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index d595abb8ef90..261293fb7097 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -56,6 +56,8 @@ static struct fscrypt_mode * select_encryption_mode(const union fscrypt_policy *policy, const struct inode *inode) { + BUILD_BUG_ON(ARRAY_SIZE(fscrypt_modes) != FSCRYPT_MODE_MAX + 1); + if (S_ISREG(inode->i_mode)) return &fscrypt_modes[fscrypt_policy_contents_mode(policy)]; @@ -168,7 +170,7 @@ static int setup_per_mode_enc_key(struct fscrypt_info *ci, unsigned int hkdf_infolen = 0; int err; - if (WARN_ON(mode_num > __FSCRYPT_MODE_MAX)) + if (WARN_ON(mode_num > FSCRYPT_MODE_MAX)) return -EINVAL; prep_key = &keys[mode_num]; @@ -335,11 +337,11 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, * Find the master key, then set up the inode's actual encryption key. * * If the master key is found in the filesystem-level keyring, then the - * corresponding 'struct key' is returned in *master_key_ret with - * ->mk_secret_sem read-locked. This is needed to ensure that only one task - * links the fscrypt_info into ->mk_decrypted_inodes (as multiple tasks may race - * to create an fscrypt_info for the same inode), and to synchronize the master - * key being removed with a new inode starting to use it. + * corresponding 'struct key' is returned in *master_key_ret with its semaphore + * read-locked. This is needed to ensure that only one task links the + * fscrypt_info into ->mk_decrypted_inodes (as multiple tasks may race to create + * an fscrypt_info for the same inode), and to synchronize the master key being + * removed with a new inode starting to use it. */ static int setup_file_encryption_key(struct fscrypt_info *ci, bool need_dirhash_key, @@ -388,7 +390,7 @@ static int setup_file_encryption_key(struct fscrypt_info *ci, } mk = key->payload.data[0]; - down_read(&mk->mk_secret_sem); + down_read(&key->sem); /* Has the secret been removed (via FS_IOC_REMOVE_ENCRYPTION_KEY)? */ if (!is_master_key_secret_present(&mk->mk_secret)) { @@ -431,7 +433,7 @@ static int setup_file_encryption_key(struct fscrypt_info *ci, return 0; out_release_key: - up_read(&mk->mk_secret_sem); + up_read(&key->sem); key_put(key); return err; } @@ -534,9 +536,7 @@ fscrypt_setup_encryption_info(struct inode *inode, res = 0; out: if (master_key) { - struct fscrypt_master_key *mk = master_key->payload.data[0]; - - up_read(&mk->mk_secret_sem); + up_read(&master_key->sem); key_put(master_key); } put_crypt_info(crypt_info); @@ -546,6 +546,11 @@ out: /** * fscrypt_get_encryption_info() - set up an inode's encryption key * @inode: the inode to set up the key for. Must be encrypted. + * @allow_unsupported: if %true, treat an unsupported encryption policy (or + * unrecognized encryption context) the same way as the key + * being unavailable, instead of returning an error. Use + * %false unless the operation being performed is needed in + * order for files (or directories) to be deleted. * * Set up ->i_crypt_info, if it hasn't already been done. * @@ -556,7 +561,7 @@ out: * encryption key is unavailable. (Use fscrypt_has_encryption_key() to * distinguish these cases.) Also can return another -errno code. */ -int fscrypt_get_encryption_info(struct inode *inode) +int fscrypt_get_encryption_info(struct inode *inode, bool allow_unsupported) { int res; union fscrypt_context ctx; @@ -567,29 +572,38 @@ int fscrypt_get_encryption_info(struct inode *inode) res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx)); if (res < 0) { + if (res == -ERANGE && allow_unsupported) + return 0; fscrypt_warn(inode, "Error %d getting encryption context", res); return res; } res = fscrypt_policy_from_context(&policy, &ctx, res); if (res) { + if (allow_unsupported) + return 0; fscrypt_warn(inode, "Unrecognized or corrupt encryption context"); return res; } - if (!fscrypt_supported_policy(&policy, inode)) + if (!fscrypt_supported_policy(&policy, inode)) { + if (allow_unsupported) + return 0; return -EINVAL; + } res = fscrypt_setup_encryption_info(inode, &policy, fscrypt_context_nonce(&ctx), IS_CASEFOLDED(inode) && S_ISDIR(inode->i_mode)); + + if (res == -ENOPKG && allow_unsupported) /* Algorithm unavailable? */ + res = 0; if (res == -ENOKEY) res = 0; return res; } -EXPORT_SYMBOL(fscrypt_get_encryption_info); /** * fscrypt_prepare_new_inode() - prepare to create a new inode in a directory @@ -710,7 +724,7 @@ int fscrypt_drop_inode(struct inode *inode) return 0; /* - * Note: since we aren't holding ->mk_secret_sem, the result here can + * Note: since we aren't holding the key semaphore, the result here can * immediately become outdated. But there's no correctness problem with * unnecessarily evicting. Nor is there a correctness problem with not * evicting while iput() is racing with the key being removed, since |