From b5695d04634fa4ccca7dcbc05bb4a66522f02e0b Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Mon, 21 Mar 2011 16:00:55 +0100 Subject: eCryptfs: write lock requested keys A requested key is write locked in order to prevent modifications on the authentication token while it is being used. Signed-off-by: Roberto Sassu Signed-off-by: Tyler Hicks --- fs/ecryptfs/keystore.c | 26 ++++++++++++++++++++------ fs/ecryptfs/main.c | 4 +++- 2 files changed, 23 insertions(+), 7 deletions(-) diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index d95dd505433e..03e609c45012 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -516,10 +516,11 @@ ecryptfs_find_global_auth_tok_for_sig( goto out_invalid_auth_tok; } + down_write(&(walker->global_auth_tok_key->sem)); rc = ecryptfs_verify_auth_tok_from_key( walker->global_auth_tok_key, auth_tok); if (rc) - goto out_invalid_auth_tok; + goto out_invalid_auth_tok_unlock; (*auth_tok_key) = walker->global_auth_tok_key; key_get(*auth_tok_key); @@ -527,6 +528,8 @@ ecryptfs_find_global_auth_tok_for_sig( } rc = -ENOENT; goto out; +out_invalid_auth_tok_unlock: + up_write(&(walker->global_auth_tok_key->sem)); out_invalid_auth_tok: printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n", sig); walker->flags |= ECRYPTFS_AUTH_TOK_INVALID; @@ -869,8 +872,10 @@ out_free_unlock: out_unlock: mutex_unlock(s->tfm_mutex); out: - if (auth_tok_key) + if (auth_tok_key) { + up_write(&(auth_tok_key->sem)); key_put(auth_tok_key); + } kfree(s); return rc; } @@ -1106,8 +1111,10 @@ out: (*filename_size) = 0; (*filename) = NULL; } - if (auth_tok_key) + if (auth_tok_key) { + up_write(&(auth_tok_key->sem)); key_put(auth_tok_key); + } kfree(s); return rc; } @@ -1638,9 +1645,10 @@ int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, (*auth_tok_key) = NULL; goto out; } - + down_write(&(*auth_tok_key)->sem); rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok); if (rc) { + up_write(&(*auth_tok_key)->sem); key_put(*auth_tok_key); (*auth_tok_key) = NULL; goto out; @@ -1865,6 +1873,7 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, find_next_matching_auth_tok: found_auth_tok = 0; if (auth_tok_key) { + up_write(&(auth_tok_key->sem)); key_put(auth_tok_key); auth_tok_key = NULL; } @@ -1951,8 +1960,10 @@ found_matching_auth_tok: out_wipe_list: wipe_auth_tok_list(&auth_tok_list); out: - if (auth_tok_key) + if (auth_tok_key) { + up_write(&(auth_tok_key->sem)); key_put(auth_tok_key); + } return rc; } @@ -2446,6 +2457,7 @@ ecryptfs_generate_key_packet_set(char *dest_base, rc = -EINVAL; goto out_free; } + up_write(&(auth_tok_key->sem)); key_put(auth_tok_key); auth_tok_key = NULL; } @@ -2460,8 +2472,10 @@ out_free: out: if (rc) (*len) = 0; - if (auth_tok_key) + if (auth_tok_key) { + up_write(&(auth_tok_key->sem)); key_put(auth_tok_key); + } mutex_unlock(&crypt_stat->keysig_list_mutex); return rc; diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 520d05f5ad01..c27c0ecf90bc 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -254,8 +254,10 @@ static int ecryptfs_init_global_auth_toks( "option: [%s]\n", global_auth_tok->sig); global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; goto out; - } else + } else { global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; + up_write(&(global_auth_tok->global_auth_tok_key)->sem); + } } out: return rc; -- cgit v1.2.3-58-ga151