From: Arun Raghavan <arunsr@xxxxxxxxxxxxxx>
The key_create_or_update() function provided by the keyring code has a default
set of permissions that are always applied to the key when created. This might
not be desirable to all clients.
Here's a patch that adds a "perm" parameter to the function to address this,
which can be set to KEY_PERM_UNDEF to revert to the current behaviour.
Signed-off-by: Arun Raghavan <arunsr@xxxxxxxxxxxxxx>
Acked-by: David Howells <dhowells@xxxxxxxxxx>
---
include/linux/key.h | 3 +++
security/keys/key.c | 18 ++++++++++--------
security/keys/keyctl.c | 3 ++-
3 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/include/linux/key.h b/include/linux/key.h
index 163f864..8b0bd33 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -67,6 +67,8 @@ struct key;
#define KEY_OTH_SETATTR 0x00000020
#define KEY_OTH_ALL 0x0000003f
+#define KEY_PERM_UNDEF 0xffffffff
+
struct seq_file;
struct user_struct;
struct signal_struct;
@@ -232,6 +234,7 @@ extern key_ref_t key_create_or_update(key_ref_t keyring,
const char *description,
const void *payload,
size_t plen,
+ key_perm_t perm,
unsigned long flags);
extern int key_update(key_ref_t key,
diff --git a/security/keys/key.c b/security/keys/key.c
index 654d23b..d98c619 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -757,11 +757,11 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
const char *description,
const void *payload,
size_t plen,
+ key_perm_t perm,
unsigned long flags)
{
struct key_type *ktype;
struct key *keyring, *key = NULL;
- key_perm_t perm;
key_ref_t key_ref;
int ret;
@@ -806,15 +806,17 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
goto found_matching_key;
}
- /* decide on the permissions we want */
- perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
- perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR;
+ /* if the client doesn't provide, decide on the permissions we want */
+ if (perm == KEY_PERM_UNDEF) {
+ perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
+ perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR;
- if (ktype->read)
- perm |= KEY_POS_READ | KEY_USR_READ;
+ if (ktype->read)
+ perm |= KEY_POS_READ | KEY_USR_READ;
- if (ktype == &key_type_keyring || ktype->update)
- perm |= KEY_USR_WRITE;
+ if (ktype == &key_type_keyring || ktype->update)
+ perm |= KEY_USR_WRITE;
+ }
/* allocate a new key */
key = key_alloc(ktype, description, current->fsuid, current->fsgid,
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 1698bf9..5f0d85b 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -111,7 +111,8 @@ asmlinkage long sys_add_key(const char __user *_type,
/* create or update the requested key and add it to the target
* keyring */
key_ref = key_create_or_update(keyring_ref, type, description,
- payload, plen, KEY_ALLOC_IN_QUOTA);
+ payload, plen, KEY_PERM_UNDEF,
+ KEY_ALLOC_IN_QUOTA);
if (!IS_ERR(key_ref)) {
ret = key_ref_to_ptr(key_ref)->serial;
key_ref_put(key_ref);
--
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