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  1. 10 Sep, 2009 5 commits
    • Roland McGrath's avatar
      binfmt_elf: fix PT_INTERP bss handling · 9f0ab4a3
      Roland McGrath authored 
      In fs/binfmt_elf.c, load_elf_interp() calls padzero() for .bss even if
the PT_LOAD has no PROT_WRITE and no .bss.  This generates EFAULT.

Here is a small test case.  (Yes, there are other, useful PT_INTERP
which have only .text and no .data/.bss.)

	----- ptinterp.S
	_start: .globl _start
		 nop
		 int3
	-----
	$ gcc -m32 -nostartfiles -nostdlib -o ptinterp ptinterp.S
	$ gcc -m32 -Wl,--dynamic-linker=ptinterp -o hello hello.c
	$ ./hello
	Segmentation fault  # during execve() itself

	After applying the patch:
	$ ./hello
	Trace trap  # user-mode execution after execve() finishes

If the ELF headers are actually self-inconsistent, then dying is fine.
But having no PROT_WRITE segment is perfectly normal and correct if
there is no segment with p_memsz > p_filesz (i.e. bss).  John Reiser
suggested checking for PROT_WRITE in the bss logic.  I think it makes
most sense to simply apply the bss logic only when there is bss.

This patch looks less trivial than it is due to some reindentation.
It just moves the "if (last_bss > elf_bss) {" test up to include the
partial-page bss logic as well as the more-pages bss logic.
Reported-by: default avatarJohn Reiser <jreiser@bitwagon.com>
Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      9f0ab4a3
    • Jason Gunthorpe's avatar
      TPM: Fixup boot probe timeout for tpm_tis driver · ec579358
      Jason Gunthorpe authored 
      When probing the device in tpm_tis_init the call request_locality
uses timeout_a, which wasn't being initalized until after
request_locality. This results in request_locality falsely timing
out if the chip is still starting. Move the initialization to before
request_locality.

This probably only matters for embedded cases (ie mine), a BIOS likely
gets the TPM into a state where this code path isn't necessary.
Signed-off-by: default avatarJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Acked-by: default avatarRajiv Andrade <srajiv@linux.vnet.ibm.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      ec579358
    • David P. Quigley's avatar
      sysfs: Add labeling support for sysfs · ddd29ec6
      David P. Quigley authored 
      This patch adds a setxattr handler to the file, directory, and symlink
inode_operations structures for sysfs. The patch uses hooks introduced in the
previous patch to handle the getting and setting of security information for
the sysfs inodes. As was suggested by Eric Biederman the struct iattr in the
sysfs_dirent structure has been replaced by a structure which contains the
iattr, secdata and secdata length to allow the changes to persist in the event
that the inode representing the sysfs_dirent is evicted. Because sysfs only
stores this information when a change is made all the optional data is moved
into one dynamically allocated field.

This patch addresses an issue where SELinux was denying virtd access to the PCI
configuration entries in sysfs. The lack of setxattr handlers for sysfs
required that a single label be assigned to all entries in sysfs. Granting virtd
access to every entry in sysfs is not an acceptable solution so fine grained
labeling of sysfs is required such that individual entries can be labeled
appropriately.

[sds:  Fixed compile-time warnings, coding style, and setting of inode security init flags.]
Signed-off-by: default avatarDavid P. Quigley <dpquigl@tycho.nsa.gov>
Signed-off-by: default avatarStephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      ddd29ec6
    • David P. Quigley's avatar
      LSM/SELinux: inode_{get,set,notify}secctx hooks to access LSM security context information. · 1ee65e37
      David P. Quigley authored 
      This patch introduces three new hooks. The inode_getsecctx hook is used to get
all relevant information from an LSM about an inode. The inode_setsecctx is
used to set both the in-core and on-disk state for the inode based on a context
derived from inode_getsecctx.The final hook inode_notifysecctx will notify the
LSM of a change for the in-core state of the inode in question. These hooks are
for use in the labeled NFS code and addresses concerns of how to set security
on an inode in a multi-xattr LSM. For historical reasons Stephen Smalley's
explanation of the reason for these hooks is pasted below.

Quote Stephen Smalley

inode_setsecctx:  Change the security context of an inode.  Updates the
in core security context managed by the security module and invokes the
fs code as needed (via __vfs_setxattr_noperm) to update any backing
xattrs that represent the context.  Example usage:  NFS server invokes
this hook to change the security context in its incore inode and on the
backing file system to a value provided by the client on a SETATTR
operation.

inode_notifysecctx:  Notify the security module of what the security
context of an inode should be.  Initializes the incore security context
managed by the security module for this inode.  Example usage:  NFS
client invokes this hook to initialize the security context in its
incore inode to the value provided by the server for the file when the
server returned the file's attributes to the client.
Signed-off-by: default avatarDavid P. Quigley <dpquigl@tycho.nsa.gov>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      1ee65e37
    • David P. Quigley's avatar
      VFS: Factor out part of vfs_setxattr so it can be called from the SELinux hook for inode_setsecctx. · b1ab7e4b
      David P. Quigley authored 
      This factors out the part of the vfs_setxattr function that performs the
setting of the xattr and its notification. This is needed so the SELinux
implementation of inode_setsecctx can handle the setting of the xattr while
maintaining the proper separation of layers.
Signed-off-by: default avatarDavid P. Quigley <dpquigl@tycho.nsa.gov>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      b1ab7e4b
  3. 09 Sep, 2009 1 commit
  5. 07 Sep, 2009 3 commits
  7. 03 Sep, 2009 1 commit
  9. 02 Sep, 2009 9 commits
    • David Howells's avatar
      KEYS: Add a keyctl to install a process's session keyring on its parent [try #6] · ee18d64c
      David Howells authored 
      Add a keyctl to install a process's session keyring onto its parent.  This
replaces the parent's session keyring.  Because the COW credential code does
not permit one process to change another process's credentials directly, the
change is deferred until userspace next starts executing again.  Normally this
will be after a wait*() syscall.

To support this, three new security hooks have been provided:
cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in
the blank security creds and key_session_to_parent() - which asks the LSM if
the process may replace its parent's session keyring.

The replacement may only happen if the process has the same ownership details
as its parent, and the process has LINK permission on the session keyring, and
the session keyring is owned by the process, and the LSM permits it.

Note that this requires alteration to each architecture's notify_resume path.
This has been done for all arches barring blackfin, m68k* and xtensa, all of
which need assembly alteration to support TIF_NOTIFY_RESUME.  This allows the
replacement to be performed at the point the parent process resumes userspace
execution.

This allows the userspace AFS pioctl emulation to fully emulate newpag() and
the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to
alter the parent process's PAG membership.  However, since kAFS doesn't use
PAGs per se, but rather dumps the keys into the session keyring, the session
keyring of the parent must be replaced if, for example, VIOCSETTOK is passed
the newpag flag.

This can be tested with the following program:

	#include <stdio.h>
	#include <stdlib.h>
	#include <keyutils.h>

	#define KEYCTL_SESSION_TO_PARENT	18

	#define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0)

	int main(int argc, char **argv)
	{
		key_serial_t keyring, key;
		long ret;

		keyring = keyctl_join_session_keyring(argv[1]);
		OSERROR(keyring, "keyctl_join_session_keyring");

		key = add_key("user", "a", "b", 1, keyring);
		OSERROR(key, "add_key");

		ret = keyctl(KEYCTL_SESSION_TO_PARENT);
		OSERROR(ret, "KEYCTL_SESSION_TO_PARENT");

		return 0;
	}

Compiled and linked with -lkeyutils, you should see something like:

	[dhowells@andromeda ~]$ keyctl show
	Session Keyring
	       -3 --alswrv   4043  4043  keyring: _ses
	355907932 --alswrv   4043    -1   \_ keyring: _uid.4043
	[dhowells@andromeda ~]$ /tmp/newpag
	[dhowells@andromeda ~]$ keyctl show
	Session Keyring
	       -3 --alswrv   4043  4043  keyring: _ses
	1055658746 --alswrv   4043  4043   \_ user: a
	[dhowells@andromeda ~]$ /tmp/newpag hello
	[dhowells@andromeda ~]$ keyctl show
	Session Keyring
	       -3 --alswrv   4043  4043  keyring: hello
	340417692 --alswrv   4043  4043   \_ user: a

Where the test program creates a new session keyring, sticks a user key named
'a' into it and then installs it on its parent.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      ee18d64c
    • David Howells's avatar
      KEYS: Extend TIF_NOTIFY_RESUME to (almost) all architectures [try #6] · d0420c83
      David Howells authored 
      Implement TIF_NOTIFY_RESUME for most of those architectures in which isn't yet
available, and, whilst we're at it, have it call the appropriate tracehook.

After this patch, blackfin, m68k* and xtensa still lack support and need
alteration of assembly code to make it work.

Resume notification can then be used (by a later patch) to install a new
session keyring on the parent of a process.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>

cc: linux-arch@vger.kernel.org
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      d0420c83
    • David Howells's avatar
      KEYS: Do some whitespace cleanups [try #6] · 7b1b9164
      David Howells authored 
      Do some whitespace cleanups in the key management code.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      7b1b9164
    • Serge E. Hallyn's avatar
      KEYS: Make /proc/keys use keyid not numread as file position [try #6] · ad73a717
      Serge E. Hallyn authored 
      Make the file position maintained by /proc/keys represent the ID of the key
just read rather than the number of keys read.  This should make it faster to
perform a lookup as we don't have to scan the key ID tree from the beginning to
find the current position.
Signed-off-by: default avatarSerge E. Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      ad73a717
    • David Howells's avatar
      KEYS: Add garbage collection for dead, revoked and expired keys. [try #6] · 5d135440
      David Howells authored 
      Add garbage collection for dead, revoked and expired keys.  This involved
erasing all links to such keys from keyrings that point to them.  At that
point, the key will be deleted in the normal manner.

Keyrings from which garbage collection occurs are shrunk and their quota
consumption reduced as appropriate.

Dead keys (for which the key type has been removed) will be garbage collected
immediately.

Revoked and expired keys will hang around for a number of seconds, as set in
/proc/sys/kernel/keys/gc_delay before being automatically removed.  The default
is 5 minutes.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      5d135440
    • David Howells's avatar
      KEYS: Flag dead keys to induce EKEYREVOKED [try #6] · f041ae2f
      David Howells authored 
      Set the KEY_FLAG_DEAD flag on keys for which the type has been removed.  This
causes the key_permission() function to return EKEYREVOKED in response to
various commands.  It does not, however, prevent unlinking or clearing of
keyrings from detaching the key.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      f041ae2f
    • David Howells's avatar
      KEYS: Allow keyctl_revoke() on keys that have SETATTR but not WRITE perm [try #6] · 0c2c9a3f
      David Howells authored 
      Allow keyctl_revoke() to operate on keys that have SETATTR but not WRITE
permission, rather than only on keys that have WRITE permission.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      0c2c9a3f
    • David Howells's avatar
      KEYS: Deal with dead-type keys appropriately [try #6] · 5593122e
      David Howells authored 
      Allow keys for which the key type has been removed to be unlinked.  Currently
dead-type keys can only be disposed of by completely clearing the keyrings
that point to them.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      5593122e
    • David Howells's avatar
      CRED: Add some configurable debugging [try #6] · e0e81739
      David Howells authored 
      Add a config option (CONFIG_DEBUG_CREDENTIALS) to turn on some debug checking
for credential management.  The additional code keeps track of the number of
pointers from task_structs to any given cred struct, and checks to see that
this number never exceeds the usage count of the cred struct (which includes
all references, not just those from task_structs).

Furthermore, if SELinux is enabled, the code also checks that the security
pointer in the cred struct is never seen to be invalid.

This attempts to catch the bug whereby inode_has_perm() faults in an nfsd
kernel thread on seeing cred->security be a NULL pointer (it appears that the
credential struct has been previously released):

	http://www.kerneloops.org/oops.php?number=252883Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      e0e81739
  11. 31 Aug, 2009 2 commits
    • Paul Moore's avatar
      selinux: Support for the new TUN LSM hooks · ed6d76e4
      Paul Moore authored 
      Add support for the new TUN LSM hooks: security_tun_dev_create(),
security_tun_dev_post_create() and security_tun_dev_attach().  This includes
the addition of a new object class, tun_socket, which represents the socks
associated with TUN devices.  The _tun_dev_create() and _tun_dev_post_create()
hooks are fairly similar to the standard socket functions but _tun_dev_attach()
is a bit special.  The _tun_dev_attach() is unique because it involves a
domain attaching to an existing TUN device and its associated tun_socket
object, an operation which does not exist with standard sockets and most
closely resembles a relabel operation.
Signed-off-by: default avatarPaul Moore <paul.moore@hp.com>
Acked-by: default avatarEric Paris <eparis@parisplace.org>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      ed6d76e4
    • Paul Moore's avatar
      lsm: Add hooks to the TUN driver · 2b980dbd
      Paul Moore authored 
      The TUN driver lacks any LSM hooks which makes it difficult for LSM modules,
such as SELinux, to enforce access controls on network traffic generated by
TUN users; this is particularly problematic for virtualization apps such as
QEMU and KVM.  This patch adds three new LSM hooks designed to control the
creation and attachment of TUN devices, the hooks are:

 * security_tun_dev_create()
   Provides access control for the creation of new TUN devices

 * security_tun_dev_post_create()
   Provides the ability to create the necessary socket LSM state for newly
   created TUN devices

 * security_tun_dev_attach()
   Provides access control for attaching to existing, persistent TUN devices
   and the ability to update the TUN device's socket LSM state as necessary
Signed-off-by: default avatarPaul Moore <paul.moore@hp.com>
Acked-by: default avatarEric Paris <eparis@parisplace.org>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      2b980dbd
  13. 24 Aug, 2009 1 commit
  15. 21 Aug, 2009 2 commits
  17. 19 Aug, 2009 12 commits
  19. 18 Aug, 2009 4 commits