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r: 235098
b: refs/heads/master
c: ee009e4
h: refs/heads/master
v: v3
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David Howells authored and James Morris committed Mar 8, 2011
1 parent b491851 commit 759a508
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Showing 7 changed files with 168 additions and 12 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: fdd1b94581782a2ddf9124414e5b7a5f48ce2f9c
refs/heads/master: ee009e4a0d4555ed522a631bae9896399674f064
15 changes: 11 additions & 4 deletions trunk/Documentation/keys.txt
Original file line number Diff line number Diff line change
Expand Up @@ -637,6 +637,9 @@ The keyctl syscall functions are:
long keyctl(KEYCTL_INSTANTIATE, key_serial_t key,
const void *payload, size_t plen,
key_serial_t keyring);
long keyctl(KEYCTL_INSTANTIATE_IOV, key_serial_t key,
const struct iovec *payload_iov, unsigned ioc,
key_serial_t keyring);

If the kernel calls back to userspace to complete the instantiation of a
key, userspace should use this call to supply data for the key before the
Expand All @@ -652,6 +655,9 @@ The keyctl syscall functions are:

The payload and plen arguments describe the payload data as for add_key().

The payload_iov and ioc arguments describe the payload data in an iovec
array instead of a single buffer.


(*) Negatively instantiate a partially constructed key.

Expand Down Expand Up @@ -1244,10 +1250,11 @@ hand the request off to (perhaps a path held in placed in another key by, for
example, the KDE desktop manager).

The program (or whatever it calls) should finish construction of the key by
calling KEYCTL_INSTANTIATE, which also permits it to cache the key in one of
the keyrings (probably the session ring) before returning. Alternatively, the
key can be marked as negative with KEYCTL_NEGATE or KEYCTL_REJECT; this also
permits the key to be cached in one of the keyrings.
calling KEYCTL_INSTANTIATE or KEYCTL_INSTANTIATE_IOV, which also permits it to
cache the key in one of the keyrings (probably the session ring) before
returning. Alternatively, the key can be marked as negative with KEYCTL_NEGATE
or KEYCTL_REJECT; this also permits the key to be cached in one of the
keyrings.

If it returns with the key remaining in the unconstructed state, the key will
be marked as being negative, it will be added to the session keyring, and an
Expand Down
5 changes: 5 additions & 0 deletions trunk/arch/x86/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -2138,6 +2138,11 @@ config SYSVIPC_COMPAT
def_bool y
depends on COMPAT && SYSVIPC

config KEYS_COMPAT
bool
depends on COMPAT && KEYS
default y

endmenu


Expand Down
1 change: 1 addition & 0 deletions trunk/include/linux/keyctl.h
Original file line number Diff line number Diff line change
Expand Up @@ -54,5 +54,6 @@
#define KEYCTL_GET_SECURITY 17 /* get key security label */
#define KEYCTL_SESSION_TO_PARENT 18 /* apply session keyring to parent process */
#define KEYCTL_REJECT 19 /* reject a partially constructed key */
#define KEYCTL_INSTANTIATE_IOV 20 /* instantiate a partially constructed key */

#endif /* _LINUX_KEYCTL_H */
47 changes: 47 additions & 0 deletions trunk/security/keys/compat.c
Original file line number Diff line number Diff line change
Expand Up @@ -12,8 +12,51 @@
#include <linux/syscalls.h>
#include <linux/keyctl.h>
#include <linux/compat.h>
#include <linux/slab.h>
#include "internal.h"

/*
* Instantiate a key with the specified compatibility 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 compat_keyctl_instantiate_key_iov(
key_serial_t id,
const struct compat_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 = compat_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);
}

/*
* The key control system call, 32-bit compatibility version for 64-bit archs
*
Expand Down Expand Up @@ -88,6 +131,10 @@ asmlinkage long compat_sys_keyctl(u32 option,
case KEYCTL_REJECT:
return keyctl_reject_key(arg2, arg3, arg4, arg5);

case KEYCTL_INSTANTIATE_IOV:
return compat_keyctl_instantiate_key_iov(
arg2, compat_ptr(arg3), arg4, arg5);

default:
return -EOPNOTSUPP;
}
Expand Down
7 changes: 7 additions & 0 deletions trunk/security/keys/internal.h
Original file line number Diff line number Diff line change
Expand Up @@ -215,6 +215,13 @@ extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
size_t buflen);
extern long keyctl_session_to_parent(void);
extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
extern long keyctl_instantiate_key_iov(key_serial_t,
const struct iovec __user *,
unsigned, key_serial_t);

extern long keyctl_instantiate_key_common(key_serial_t,
const struct iovec __user *,
unsigned, size_t, key_serial_t);

/*
* Debugging key validation
Expand Down
103 changes: 96 additions & 7 deletions trunk/security/keys/keyctl.c
Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand All @@ -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;
Expand Down Expand Up @@ -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) {
Expand All @@ -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;
}

Expand Down Expand Up @@ -996,6 +1012,72 @@ long keyctl_instantiate_key(key_serial_t id,
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.
Expand Down Expand Up @@ -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;
}
Expand Down

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