Commit a4e3b8d7 authored May 22, 2014 by Mimi Zohar

KEYS: special dot prefixed keyring name bug fix



Dot prefixed keyring names are supposed to be reserved for the
kernel, but add_key() calls key_get_type_from_user(), which
incorrectly verifies the 'type' field, not the 'description' field.
This patch verifies the 'description' field isn't dot prefixed,
when creating a new keyring, and removes the dot prefix test in
key_get_type_from_user().

Changelog v6:
- whitespace and other cleanup

Changelog v5:
- Only prevent userspace from creating a dot prefixed keyring, not
  regular keys  - Dmitry

Reported-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>

parent 32c2e675

security/keys/keyctl.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -37,8 +37,6 @@ static int key_get_type_from_user(char *type,
		return ret;
		if (ret == 0 \|\| ret >= len)
		return -EINVAL;
		if (type[0] == '.')
		return -EPERM;
		type[len - 1] = '\0';
		return 0;
		}
		@@ -86,6 +84,10 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
		if (!*description) {
		kfree(description);
		description = NULL;
		} else if ((description[0] == '.') &&
		(strncmp(type, "keyring", 7) == 0)) {
		ret = -EPERM;
		goto error2;
		}
		}

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