diff options
| author | Christian Göttsche <cgzones@googlemail.com> | 2023-05-11 14:32:52 +0200 |
|---|---|---|
| committer | Jarkko Sakkinen <jarkko@kernel.org> | 2023-07-28 18:07:41 +0000 |
| commit | 2d7f105edbb3b2be5ffa4d833abbf9b6965e9ce7 (patch) | |
| tree | f6ebc1b970968129a1bacc8b1468de0fbe77f93d /security | |
| parent | 57012c57536f8814dec92e74197ee96c3498d24e (diff) | |
security: keys: perform capable check only on privileged operations
If the current task fails the check for the queried capability via
`capable(CAP_SYS_ADMIN)` LSMs like SELinux generate a denial message.
Issuing such denial messages unnecessarily can lead to a policy author
granting more privileges to a subject than needed to silence them.
Reorder CAP_SYS_ADMIN checks after the check whether the operation is
actually privileged.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'security')
| -rw-r--r-- | security/keys/keyctl.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index d54f73c558f7..19be69fa4d05 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -980,14 +980,19 @@ long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) ret = -EACCES; down_write(&key->sem); - if (!capable(CAP_SYS_ADMIN)) { + { + bool is_privileged_op = false; + /* only the sysadmin can chown a key to some other UID */ if (user != (uid_t) -1 && !uid_eq(key->uid, uid)) - goto error_put; + is_privileged_op = true; /* only the sysadmin can set the key's GID to a group other * than one of those that the current process subscribes to */ if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid)) + is_privileged_op = true; + + if (is_privileged_op && !capable(CAP_SYS_ADMIN)) goto error_put; } @@ -1088,7 +1093,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) down_write(&key->sem); /* if we're not the sysadmin, we can only change a key that we own */ - if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) { + if (uid_eq(key->uid, current_fsuid()) || capable(CAP_SYS_ADMIN)) { key->perm = perm; notify_key(key, NOTIFY_KEY_SETATTR, 0); ret = 0; |