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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-19 19:21:36 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-19 19:21:36 +0300 |
commit | f4f27d0028aabce57e44c16c2fdefccd6310d2f3 (patch) | |
tree | 09f25601316d22b64165c19042da51c101bde3c4 /security/keys/keyring.c | |
parent | 2600a46ee0ed57c0e0a382c2a37ebac64d374d20 (diff) | |
parent | b937190c40de0f6f07f592042e3097b16c6b0130 (diff) | |
download | linux-f4f27d0028aabce57e44c16c2fdefccd6310d2f3.tar.xz |
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
"Highlights:
- A new LSM, "LoadPin", from Kees Cook is added, which allows forcing
of modules and firmware to be loaded from a specific device (this
is from ChromeOS, where the device as a whole is verified
cryptographically via dm-verity).
This is disabled by default but can be configured to be enabled by
default (don't do this if you don't know what you're doing).
- Keys: allow authentication data to be stored in an asymmetric key.
Lots of general fixes and updates.
- SELinux: add restrictions for loading of kernel modules via
finit_module(). Distinguish non-init user namespace capability
checks. Apply execstack check on thread stacks"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (48 commits)
LSM: LoadPin: provide enablement CONFIG
Yama: use atomic allocations when reporting
seccomp: Fix comment typo
ima: add support for creating files using the mknodat syscall
ima: fix ima_inode_post_setattr
vfs: forbid write access when reading a file into memory
fs: fix over-zealous use of "const"
selinux: apply execstack check on thread stacks
selinux: distinguish non-init user namespace capability checks
LSM: LoadPin for kernel file loading restrictions
fs: define a string representation of the kernel_read_file_id enumeration
Yama: consolidate error reporting
string_helpers: add kstrdup_quotable_file
string_helpers: add kstrdup_quotable_cmdline
string_helpers: add kstrdup_quotable
selinux: check ss_initialized before revalidating an inode label
selinux: delay inode label lookup as long as possible
selinux: don't revalidate an inode's label when explicitly setting it
selinux: Change bool variable name to index.
KEYS: Add KEYCTL_DH_COMPUTE command
...
Diffstat (limited to 'security/keys/keyring.c')
-rw-r--r-- | security/keys/keyring.c | 46 |
1 files changed, 39 insertions, 7 deletions
diff --git a/security/keys/keyring.c b/security/keys/keyring.c index f931ccfeefb0..c91e4e0cea08 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -491,13 +491,17 @@ static long keyring_read(const struct key *keyring, */ struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid, const struct cred *cred, key_perm_t perm, - unsigned long flags, struct key *dest) + unsigned long flags, + int (*restrict_link)(struct key *, + const struct key_type *, + const union key_payload *), + struct key *dest) { struct key *keyring; int ret; keyring = key_alloc(&key_type_keyring, description, - uid, gid, cred, perm, flags); + uid, gid, cred, perm, flags, restrict_link); if (!IS_ERR(keyring)) { ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL); if (ret < 0) { @@ -510,6 +514,26 @@ struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid, } EXPORT_SYMBOL(keyring_alloc); +/** + * restrict_link_reject - Give -EPERM to restrict link + * @keyring: The keyring being added to. + * @type: The type of key being added. + * @payload: The payload of the key intended to be added. + * + * Reject the addition of any links to a keyring. It can be overridden by + * passing KEY_ALLOC_BYPASS_RESTRICTION to key_instantiate_and_link() when + * adding a key to a keyring. + * + * This is meant to be passed as the restrict_link parameter to + * keyring_alloc(). + */ +int restrict_link_reject(struct key *keyring, + const struct key_type *type, + const union key_payload *payload) +{ + return -EPERM; +} + /* * By default, we keys found by getting an exact match on their descriptions. */ @@ -1191,6 +1215,16 @@ void __key_link_end(struct key *keyring, up_write(&keyring->sem); } +/* + * Check addition of keys to restricted keyrings. + */ +static int __key_link_check_restriction(struct key *keyring, struct key *key) +{ + if (!keyring->restrict_link) + return 0; + return keyring->restrict_link(keyring, key->type, &key->payload); +} + /** * key_link - Link a key to a keyring * @keyring: The keyring to make the link in. @@ -1221,14 +1255,12 @@ int key_link(struct key *keyring, struct key *key) key_check(keyring); key_check(key); - if (test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags) && - !test_bit(KEY_FLAG_TRUSTED, &key->flags)) - return -EPERM; - ret = __key_link_begin(keyring, &key->index_key, &edit); if (ret == 0) { kdebug("begun {%d,%d}", keyring->serial, atomic_read(&keyring->usage)); - ret = __key_link_check_live_key(keyring, key); + ret = __key_link_check_restriction(keyring, key); + if (ret == 0) + ret = __key_link_check_live_key(keyring, key); if (ret == 0) __key_link(key, &edit); __key_link_end(keyring, &key->index_key, edit); |