From ee009e4a0d4555ed522a631bae9896399674f064 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 7 Mar 2011 15:06:20 +0000 Subject: KEYS: Add an iovec version of KEYCTL_INSTANTIATE Add a keyctl op (KEYCTL_INSTANTIATE_IOV) that is like KEYCTL_INSTANTIATE, but takes an iovec array and concatenates the data in-kernel into one buffer. Since the KEYCTL_INSTANTIATE copies the data anyway, this isn't too much of a problem. Signed-off-by: David Howells Signed-off-by: James Morris --- security/keys/keyctl.c | 103 +++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 96 insertions(+), 7 deletions(-) (limited to 'security/keys/keyctl.c') diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 0d7b1946ff94..427fddcaeb19 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -912,6 +912,21 @@ static int keyctl_change_reqkey_auth(struct key *key) return commit_creds(new); } +/* + * Copy the iovec data from userspace + */ +static long copy_from_user_iovec(void *buffer, const struct iovec *iov, + unsigned ioc) +{ + for (; ioc > 0; ioc--) { + if (copy_from_user(buffer, iov->iov_base, iov->iov_len) != 0) + return -EFAULT; + buffer += iov->iov_len; + iov++; + } + return 0; +} + /* * Instantiate a key with the specified payload and link the key into the * destination keyring if one is given. @@ -921,10 +936,11 @@ static int keyctl_change_reqkey_auth(struct key *key) * * If successful, 0 will be returned. */ -long keyctl_instantiate_key(key_serial_t id, - const void __user *_payload, - size_t plen, - key_serial_t ringid) +long keyctl_instantiate_key_common(key_serial_t id, + const struct iovec *payload_iov, + unsigned ioc, + size_t plen, + key_serial_t ringid) { const struct cred *cred = current_cred(); struct request_key_auth *rka; @@ -953,7 +969,7 @@ long keyctl_instantiate_key(key_serial_t id, /* pull the payload in if one was supplied */ payload = NULL; - if (_payload) { + if (payload_iov) { ret = -ENOMEM; payload = kmalloc(plen, GFP_KERNEL); if (!payload) { @@ -965,8 +981,8 @@ long keyctl_instantiate_key(key_serial_t id, goto error; } - ret = -EFAULT; - if (copy_from_user(payload, _payload, plen) != 0) + ret = copy_from_user_iovec(payload, payload_iov, ioc); + if (ret < 0) goto error2; } @@ -996,6 +1012,72 @@ error: return ret; } +/* + * Instantiate a key with the specified payload and link the key into the + * destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +long keyctl_instantiate_key(key_serial_t id, + const void __user *_payload, + size_t plen, + key_serial_t ringid) +{ + if (_payload && plen) { + struct iovec iov[1] = { + [0].iov_base = (void __user *)_payload, + [0].iov_len = plen + }; + + return keyctl_instantiate_key_common(id, iov, 1, plen, ringid); + } + + return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); +} + +/* + * Instantiate a key with the specified multipart payload and link the key into + * the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +long keyctl_instantiate_key_iov(key_serial_t id, + const struct iovec __user *_payload_iov, + unsigned ioc, + key_serial_t ringid) +{ + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + long ret; + + if (_payload_iov == 0 || ioc == 0) + goto no_payload; + + ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc, + ARRAY_SIZE(iovstack), iovstack, &iov); + if (ret < 0) + return ret; + if (ret == 0) + goto no_payload_free; + + ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid); + + if (iov != iovstack) + kfree(iov); + return ret; + +no_payload_free: + if (iov != iovstack) + kfree(iov); +no_payload: + return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); +} + /* * Negatively instantiate the key with the given timeout (in seconds) and link * the key into the destination keyring if one is given. @@ -1528,6 +1610,13 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, (unsigned) arg4, (key_serial_t) arg5); + case KEYCTL_INSTANTIATE_IOV: + return keyctl_instantiate_key_iov( + (key_serial_t) arg2, + (const struct iovec __user *) arg3, + (unsigned) arg4, + (key_serial_t) arg5); + default: return -EOPNOTSUPP; } -- cgit v1.2.3-59-g8ed1b