diff options
Diffstat (limited to 'security/integrity/evm/evm_secfs.c')
| -rw-r--r-- | security/integrity/evm/evm_secfs.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c index c8dccd54d501..319cf16d6603 100644 --- a/security/integrity/evm/evm_secfs.c +++ b/security/integrity/evm/evm_secfs.c @@ -40,7 +40,7 @@ static ssize_t evm_read_key(struct file *filp, char __user *buf, if (*ppos != 0) return 0; - sprintf(temp, "%d", evm_initialized); + sprintf(temp, "%d", (evm_initialized & ~EVM_SETUP)); rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); return rc; @@ -61,24 +61,29 @@ static ssize_t evm_read_key(struct file *filp, char __user *buf, static ssize_t evm_write_key(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - char temp[80]; - int i; + int i, ret; - if (!capable(CAP_SYS_ADMIN) || (evm_initialized & EVM_INIT_HMAC)) + if (!capable(CAP_SYS_ADMIN) || (evm_initialized & EVM_SETUP)) return -EPERM; - if (count >= sizeof(temp) || count == 0) - return -EINVAL; - - if (copy_from_user(temp, buf, count) != 0) - return -EFAULT; + ret = kstrtoint_from_user(buf, count, 0, &i); - temp[count] = '\0'; + if (ret) + return ret; - if ((sscanf(temp, "%d", &i) != 1) || (i != 1)) + /* Reject invalid values */ + if (!i || (i & ~EVM_INIT_MASK) != 0) return -EINVAL; - evm_init_key(); + if (i & EVM_INIT_HMAC) { + ret = evm_init_key(); + if (ret != 0) + return ret; + /* Forbid further writes after the symmetric key is loaded */ + i |= EVM_SETUP; + } + + evm_initialized |= i; return count; } |