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  1. 17 8月, 2009 2 次提交
    • E
      Security/SELinux: seperate lsm specific mmap_min_addr · 788084ab
      由 Eric Paris 提交于 
      Currently SELinux enforcement of controls on the ability to map low memory
is determined by the mmap_min_addr tunable.  This patch causes SELinux to
ignore the tunable and instead use a seperate Kconfig option specific to how
much space the LSM should protect.

The tunable will now only control the need for CAP_SYS_RAWIO and SELinux
permissions will always protect the amount of low memory designated by
CONFIG_LSM_MMAP_MIN_ADDR.

This allows users who need to disable the mmap_min_addr controls (usual reason
being they run WINE as a non-root user) to do so and still have SELinux
controls preventing confined domains (like a web server) from being able to
map some area of low memory.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      788084ab
    • E
      SELinux: call cap_file_mmap in selinux_file_mmap · 8cf948e7
      由 Eric Paris 提交于 
      Currently SELinux does not check CAP_SYS_RAWIO in the file_mmap hook.  This
means there is no DAC check on the ability to mmap low addresses in the
memory space.  This function adds the DAC check for CAP_SYS_RAWIO while
maintaining the selinux check on mmap_zero.  This means that processes
which need to mmap low memory will need CAP_SYS_RAWIO and mmap_zero but will
NOT need the SELinux sys_rawio capability.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      8cf948e7
  3. 11 8月, 2009 1 次提交
  5. 03 6月, 2009 1 次提交
  7. 05 5月, 2009 1 次提交
  9. 30 4月, 2009 3 次提交
  11. 28 3月, 2009 2 次提交
    • P
      selinux: Remove the "compat_net" compatibility code · 58bfbb51
      由 Paul Moore 提交于 
      The SELinux "compat_net" is marked as deprecated, the time has come to
finally remove it from the kernel.  Further code simplifications are
likely in the future, but this patch was intended to be a simple,
straight-up removal of the compat_net code.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      58bfbb51
    • P
      netlabel: Label incoming TCP connections correctly in SELinux · 389fb800
      由 Paul Moore 提交于 
      The current NetLabel/SELinux behavior for incoming TCP connections works but
only through a series of happy coincidences that rely on the limited nature of
standard CIPSO (only able to convey MLS attributes) and the write equality
imposed by the SELinux MLS constraints.  The problem is that network sockets
created as the result of an incoming TCP connection were not on-the-wire
labeled based on the security attributes of the parent socket but rather based
on the wire label of the remote peer.  The issue had to do with how IP options
were managed as part of the network stack and where the LSM hooks were in
relation to the code which set the IP options on these newly created child
sockets.  While NetLabel/SELinux did correctly set the socket's on-the-wire
label it was promptly cleared by the network stack and reset based on the IP
options of the remote peer.

This patch, in conjunction with a prior patch that adjusted the LSM hook
locations, works to set the correct on-the-wire label format for new incoming
connections through the security_inet_conn_request() hook.  Besides the
correct behavior there are many advantages to this change, the most significant
is that all of the NetLabel socket labeling code in SELinux now lives in hooks
which can return error codes to the core stack which allows us to finally get
ride of the selinux_netlbl_inode_permission() logic which greatly simplfies
the NetLabel/SELinux glue code.  In the process of developing this patch I
also ran into a small handful of AF_INET6 cleanliness issues that have been
fixed which should make the code safer and easier to extend in the future.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      389fb800
  13. 10 3月, 2009 1 次提交
  15. 06 3月, 2009 1 次提交
  17. 14 2月, 2009 3 次提交
  19. 02 2月, 2009 1 次提交
  21. 30 1月, 2009 18 次提交
  23. 19 1月, 2009 3 次提交
  25. 07 1月, 2009 2 次提交
    • D
      CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #3] · 3699c53c
      由 David Howells 提交于 
      Fix a regression in cap_capable() due to:

	commit 3b11a1de
	Author: David Howells <dhowells@redhat.com>
	Date:   Fri Nov 14 10:39:26 2008 +1100

	    CRED: Differentiate objective and effective subjective credentials on a task

The problem is that the above patch allows a process to have two sets of
credentials, and for the most part uses the subjective credentials when
accessing current's creds.

There is, however, one exception: cap_capable(), and thus capable(), uses the
real/objective credentials of the target task, whether or not it is the current
task.

Ordinarily this doesn't matter, since usually the two cred pointers in current
point to the same set of creds.  However, sys_faccessat() makes use of this
facility to override the credentials of the calling process to make its test,
without affecting the creds as seen from other processes.

One of the things sys_faccessat() does is to make an adjustment to the
effective capabilities mask, which cap_capable(), as it stands, then ignores.

The affected capability check is in generic_permission():

	if (!(mask & MAY_EXEC) || execute_ok(inode))
		if (capable(CAP_DAC_OVERRIDE))
			return 0;

This change passes the set of credentials to be tested down into the commoncap
and SELinux code.  The security functions called by capable() and
has_capability() select the appropriate set of credentials from the process
being checked.

This can be tested by compiling the following program from the XFS testsuite:

/*
 *  t_access_root.c - trivial test program to show permission bug.
 *
 *  Written by Michael Kerrisk - copyright ownership not pursued.
 *  Sourced from: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-10/6030.html
 */
#include <limits.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>

#define UID 500
#define GID 100
#define PERM 0
#define TESTPATH "/tmp/t_access"

static void
errExit(char *msg)
{
    perror(msg);
    exit(EXIT_FAILURE);
} /* errExit */

static void
accessTest(char *file, int mask, char *mstr)
{
    printf("access(%s, %s) returns %d\n", file, mstr, access(file, mask));
} /* accessTest */

int
main(int argc, char *argv[])
{
    int fd, perm, uid, gid;
    char *testpath;
    char cmd[PATH_MAX + 20];

    testpath = (argc > 1) ? argv[1] : TESTPATH;
    perm = (argc > 2) ? strtoul(argv[2], NULL, 8) : PERM;
    uid = (argc > 3) ? atoi(argv[3]) : UID;
    gid = (argc > 4) ? atoi(argv[4]) : GID;

    unlink(testpath);

    fd = open(testpath, O_RDWR | O_CREAT, 0);
    if (fd == -1) errExit("open");

    if (fchown(fd, uid, gid) == -1) errExit("fchown");
    if (fchmod(fd, perm) == -1) errExit("fchmod");
    close(fd);

    snprintf(cmd, sizeof(cmd), "ls -l %s", testpath);
    system(cmd);

    if (seteuid(uid) == -1) errExit("seteuid");

    accessTest(testpath, 0, "0");
    accessTest(testpath, R_OK, "R_OK");
    accessTest(testpath, W_OK, "W_OK");
    accessTest(testpath, X_OK, "X_OK");
    accessTest(testpath, R_OK | W_OK, "R_OK | W_OK");
    accessTest(testpath, R_OK | X_OK, "R_OK | X_OK");
    accessTest(testpath, W_OK | X_OK, "W_OK | X_OK");
    accessTest(testpath, R_OK | W_OK | X_OK, "R_OK | W_OK | X_OK");

    exit(EXIT_SUCCESS);
} /* main */

This can be run against an Ext3 filesystem as well as against an XFS
filesystem.  If successful, it will show:

	[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
	---------- 1 dhowells dhowells 0 2008-12-31 03:00 /tmp/xxx
	access(/tmp/xxx, 0) returns 0
	access(/tmp/xxx, R_OK) returns 0
	access(/tmp/xxx, W_OK) returns 0
	access(/tmp/xxx, X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK) returns 0
	access(/tmp/xxx, R_OK | X_OK) returns -1
	access(/tmp/xxx, W_OK | X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1

If unsuccessful, it will show:

	[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
	---------- 1 dhowells dhowells 0 2008-12-31 02:56 /tmp/xxx
	access(/tmp/xxx, 0) returns 0
	access(/tmp/xxx, R_OK) returns -1
	access(/tmp/xxx, W_OK) returns -1
	access(/tmp/xxx, X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK) returns -1
	access(/tmp/xxx, R_OK | X_OK) returns -1
	access(/tmp/xxx, W_OK | X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1

I've also tested the fix with the SELinux and syscalls LTP testsuites.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      3699c53c
    • J
      Revert "CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #2]" · 29881c45
      由 James Morris 提交于 
      This reverts commit 14eaddc9.

David has a better version to come.
      29881c45
  27. 05 1月, 2009 1 次提交
    • D
      CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #2] · 14eaddc9
      由 David Howells 提交于 
      Fix a regression in cap_capable() due to:

	commit 5ff7711e635b32f0a1e558227d030c7e45b4a465
	Author: David Howells <dhowells@redhat.com>
	Date:   Wed Dec 31 02:52:28 2008 +0000

	    CRED: Differentiate objective and effective subjective credentials on a task

The problem is that the above patch allows a process to have two sets of
credentials, and for the most part uses the subjective credentials when
accessing current's creds.

There is, however, one exception: cap_capable(), and thus capable(), uses the
real/objective credentials of the target task, whether or not it is the current
task.

Ordinarily this doesn't matter, since usually the two cred pointers in current
point to the same set of creds.  However, sys_faccessat() makes use of this
facility to override the credentials of the calling process to make its test,
without affecting the creds as seen from other processes.

One of the things sys_faccessat() does is to make an adjustment to the
effective capabilities mask, which cap_capable(), as it stands, then ignores.

The affected capability check is in generic_permission():

	if (!(mask & MAY_EXEC) || execute_ok(inode))
		if (capable(CAP_DAC_OVERRIDE))
			return 0;

This change splits capable() from has_capability() down into the commoncap and
SELinux code.  The capable() security op now only deals with the current
process, and uses the current process's subjective creds.  A new security op -
task_capable() - is introduced that can check any task's objective creds.

strictly the capable() security op is superfluous with the presence of the
task_capable() op, however it should be faster to call the capable() op since
two fewer arguments need be passed down through the various layers.

This can be tested by compiling the following program from the XFS testsuite:

/*
 *  t_access_root.c - trivial test program to show permission bug.
 *
 *  Written by Michael Kerrisk - copyright ownership not pursued.
 *  Sourced from: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-10/6030.html
 */
#include <limits.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>

#define UID 500
#define GID 100
#define PERM 0
#define TESTPATH "/tmp/t_access"

static void
errExit(char *msg)
{
    perror(msg);
    exit(EXIT_FAILURE);
} /* errExit */

static void
accessTest(char *file, int mask, char *mstr)
{
    printf("access(%s, %s) returns %d\n", file, mstr, access(file, mask));
} /* accessTest */

int
main(int argc, char *argv[])
{
    int fd, perm, uid, gid;
    char *testpath;
    char cmd[PATH_MAX + 20];

    testpath = (argc > 1) ? argv[1] : TESTPATH;
    perm = (argc > 2) ? strtoul(argv[2], NULL, 8) : PERM;
    uid = (argc > 3) ? atoi(argv[3]) : UID;
    gid = (argc > 4) ? atoi(argv[4]) : GID;

    unlink(testpath);

    fd = open(testpath, O_RDWR | O_CREAT, 0);
    if (fd == -1) errExit("open");

    if (fchown(fd, uid, gid) == -1) errExit("fchown");
    if (fchmod(fd, perm) == -1) errExit("fchmod");
    close(fd);

    snprintf(cmd, sizeof(cmd), "ls -l %s", testpath);
    system(cmd);

    if (seteuid(uid) == -1) errExit("seteuid");

    accessTest(testpath, 0, "0");
    accessTest(testpath, R_OK, "R_OK");
    accessTest(testpath, W_OK, "W_OK");
    accessTest(testpath, X_OK, "X_OK");
    accessTest(testpath, R_OK | W_OK, "R_OK | W_OK");
    accessTest(testpath, R_OK | X_OK, "R_OK | X_OK");
    accessTest(testpath, W_OK | X_OK, "W_OK | X_OK");
    accessTest(testpath, R_OK | W_OK | X_OK, "R_OK | W_OK | X_OK");

    exit(EXIT_SUCCESS);
} /* main */

This can be run against an Ext3 filesystem as well as against an XFS
filesystem.  If successful, it will show:

	[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
	---------- 1 dhowells dhowells 0 2008-12-31 03:00 /tmp/xxx
	access(/tmp/xxx, 0) returns 0
	access(/tmp/xxx, R_OK) returns 0
	access(/tmp/xxx, W_OK) returns 0
	access(/tmp/xxx, X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK) returns 0
	access(/tmp/xxx, R_OK | X_OK) returns -1
	access(/tmp/xxx, W_OK | X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1

If unsuccessful, it will show:

	[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
	---------- 1 dhowells dhowells 0 2008-12-31 02:56 /tmp/xxx
	access(/tmp/xxx, 0) returns 0
	access(/tmp/xxx, R_OK) returns -1
	access(/tmp/xxx, W_OK) returns -1
	access(/tmp/xxx, X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK) returns -1
	access(/tmp/xxx, R_OK | X_OK) returns -1
	access(/tmp/xxx, W_OK | X_OK) returns -1
	access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1

I've also tested the fix with the SELinux and syscalls LTP testsuites.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
      14eaddc9