diff --git a/Documentation/filesystems/ubifs.txt b/Documentation/filesystems/ubifs.txt index a0a61d2f389f..acc80442a3bb 100644 --- a/Documentation/filesystems/ubifs.txt +++ b/Documentation/filesystems/ubifs.txt @@ -91,6 +91,13 @@ chk_data_crc do not skip checking CRCs on data nodes compr=none override default compressor and set it to "none" compr=lzo override default compressor and set it to "lzo" compr=zlib override default compressor and set it to "zlib" +auth_key= specify the key used for authenticating the filesystem. + Passing this option makes authentication mandatory. + The passed key must be present in the kernel keyring + and must be of type 'logon' +auth_hash_name= The hash algorithm used for authentication. Used for + both hashing and for creating HMACs. Typical values + include "sha256" or "sha512" Quick usage instructions diff --git a/fs/ubifs/Kconfig b/fs/ubifs/Kconfig index 853c77579b4e..529856fbccd0 100644 --- a/fs/ubifs/Kconfig +++ b/fs/ubifs/Kconfig @@ -86,3 +86,13 @@ config UBIFS_FS_SECURITY the extended attribute support in advance. If you are not using a security module, say N. + +config UBIFS_FS_AUTHENTICATION + bool "UBIFS authentication support" + select CRYPTO_HMAC + help + Enable authentication support for UBIFS. This feature offers protection + against offline changes for both data and metadata of the filesystem. + If you say yes here you should also select a hashing algorithm such as + sha256, these are not selected automatically since there are many + different options. diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index e2964ce81dee..1fac1133dadd 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -579,7 +579,9 @@ static int init_constants_early(struct ubifs_info *c) c->ranges[UBIFS_REF_NODE].len = UBIFS_REF_NODE_SZ; c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ; c->ranges[UBIFS_CS_NODE].len = UBIFS_CS_NODE_SZ; - c->ranges[UBIFS_AUTH_NODE].len = UBIFS_AUTH_NODE_SZ; + c->ranges[UBIFS_AUTH_NODE].min_len = UBIFS_AUTH_NODE_SZ; + c->ranges[UBIFS_AUTH_NODE].max_len = UBIFS_AUTH_NODE_SZ + + UBIFS_MAX_HMAC_LEN; c->ranges[UBIFS_INO_NODE].min_len = UBIFS_INO_NODE_SZ; c->ranges[UBIFS_INO_NODE].max_len = UBIFS_MAX_INO_NODE_SZ; @@ -935,6 +937,8 @@ static int check_volume_empty(struct ubifs_info *c) * Opt_no_chk_data_crc: do not check CRCs when reading data nodes * Opt_override_compr: override default compressor * Opt_assert: set ubifs_assert() action + * Opt_auth_key: The key name used for authentication + * Opt_auth_hash_name: The hash type used for authentication * Opt_err: just end of array marker */ enum { @@ -946,6 +950,8 @@ enum { Opt_no_chk_data_crc, Opt_override_compr, Opt_assert, + Opt_auth_key, + Opt_auth_hash_name, Opt_ignore, Opt_err, }; @@ -958,6 +964,8 @@ static const match_table_t tokens = { {Opt_chk_data_crc, "chk_data_crc"}, {Opt_no_chk_data_crc, "no_chk_data_crc"}, {Opt_override_compr, "compr=%s"}, + {Opt_auth_key, "auth_key=%s"}, + {Opt_auth_hash_name, "auth_hash_name=%s"}, {Opt_ignore, "ubi=%s"}, {Opt_ignore, "vol=%s"}, {Opt_assert, "assert=%s"}, @@ -1081,6 +1089,16 @@ static int ubifs_parse_options(struct ubifs_info *c, char *options, kfree(act); break; } + case Opt_auth_key: + c->auth_key_name = kstrdup(args[0].from, GFP_KERNEL); + if (!c->auth_key_name) + return -ENOMEM; + break; + case Opt_auth_hash_name: + c->auth_hash_name = kstrdup(args[0].from, GFP_KERNEL); + if (!c->auth_hash_name) + return -ENOMEM; + break; case Opt_ignore: break; default: @@ -1260,6 +1278,19 @@ static int mount_ubifs(struct ubifs_info *c) c->mounting = 1; + if (c->auth_key_name) { + if (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) { + err = ubifs_init_authentication(c); + if (err) + goto out_free; + } else { + ubifs_err(c, "auth_key_name, but UBIFS is built without" + " authentication support"); + err = -EINVAL; + goto out_free; + } + } + err = ubifs_read_superblock(c); if (err) goto out_free; @@ -1577,7 +1608,10 @@ static void ubifs_umount(struct ubifs_info *c) free_wbufs(c); free_orphans(c); ubifs_lpt_free(c, 0); + ubifs_exit_authentication(c); + kfree(c->auth_key_name); + kfree(c->auth_hash_name); kfree(c->cbuf); kfree(c->rcvrd_mst_node); kfree(c->mst_node);