linux-toradex.git/security, branch v2.6.13-rc7

[PATCH] Destruction of failed keyring oopses

2005-08-04T20:11:14+00:00

The attached patch makes sure that a keyring that failed to instantiate
properly is destroyed without oopsing [CAN-2005-2099].

The problem occurs in three stages:

 (1) The key allocator initialises the type-specific data to all zeroes. In
     the case of a keyring, this will become a link in the keyring name list
     when the keyring is instantiated.

 (2) If a user (any user) attempts to add a keyring with anything other than
     an empty payload, the keyring instantiation function will fail with an
     error and won't add the keyring to the name list.

 (3) The keyring's destructor then sees that the keyring has a description
     (name) and tries to remove the keyring from the name list, which oopses
     because the link pointers are both zero.

This bug permits any user to take down a box trivially.

Signed-Off-By: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Error during attempt to join key management session can leave semaphore pinned

2005-08-04T20:11:14+00:00

The attached patch prevents an error during the key session joining operation
from hanging future joins in the D state [CAN-2005-2098].

The problem is that the error handling path for the KEYCTL_JOIN_SESSION_KEYRING
operation has one error path that doesn't release the session management
semaphore. Further attempts to get the semaphore will then sleep for ever in
the D state.

This can happen in four situations, all involving an attempt to allocate a new
session keyring:

 (1) ENOMEM.

 (2) The users key quota being reached.

 (3) A keyring name that is an empty string.

 (4) A keyring name that is too long.

Any user may attempt this operation, and so any user can cause the problem to
occur.

Signed-Off-By: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Keys: Fix key management syscall interface bugs

2005-08-04T15:20:47+00:00

This fixes five bugs in the key management syscall interface:

 (1) add_key() returns 0 rather than EINVAL if the key type is "".

     Checking the key type isn't "" should be left to lookup_user_key().

 (2) request_key() returns ENOKEY rather than EPERM if the key type begins
     with a ".".

     lookup_user_key() can't do this because internal key types begin with a
     ".".

 (3) Key revocation always returns 0, even if it fails.

 (4) Key read can return EAGAIN rather than EACCES under some circumstances.

     A key is permitted to by read by a process if it doesn't grant read
     access, but it does grant search access and it is in the process's
     keyrings. That search returns EAGAIN if it fails, and this needs
     translating to EACCES.

 (5) request_key() never adds the new key to the destination keyring if one is
     supplied.

     The wrong macro was being used to test for an error condition: PTR_ERR()
     will always return true, whether or not there's an error; this should've
     been IS_ERR().

Signed-Off-By: David Howells 
Signed-Off-By: Linus Torvalds

[PATCH] selinux: Fix address length checks in connect hook

2005-07-29T04:46:05+00:00

This patch fixes the address length checks in the selinux_socket_connect
hook to be no more restrictive than the underlying ipv4 and ipv6 code;
otherwise, this hook can reject valid connect calls.  This patch is in
response to a bug report where an application was calling connect on an
INET6 socket with an address that didn't include the optional scope id and
failing due to these checks.

Signed-off-by: Stephen Smalley 
Signed-off-by: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] SELinux: default labeling of MLS field

2005-07-28T15:39:02+00:00

Implement kernel labeling of the MLS (multilevel security) field of
security contexts for files which have no existing MLS field.  This is to
enable upgrades of a system from non-MLS to MLS without performing a full
filesystem relabel including all of the mountpoints, which would be quite
painful for users.

With this patch, with MLS enabled, if a file has no MLS field, the kernel
internally adds an MLS field to the in-core inode (but not to the on-disk
file).  This MLS field added is the default for the superblock, allowing
per-mountpoint control over the values via fixed policy or mount options.

This patch has been tested by enabling MLS without relabeling its
filesystem, and seems to be working correctly.

Signed-off-by: James Morris 
Signed-off-by: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Keys: Base keyring size on key pointer not key struct

2005-07-08T01:23:46+00:00

The attached patch makes the keyring functions calculate the new size of a
keyring's payload based on the size of pointer to the key struct, not the size
of the key struct itself.

Signed-Off-By: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] selinux_sb_copy_data() should not require a whole page

2005-06-30T15:45:09+00:00

Currently selinux_sb_copy_data requires an entire page be allocated to
*orig when the function is called.  This "requirement" is based on the fact
that we call copy_page(in_save, nosec_save) and in_save = orig when the
data is not FS_BINARY_MOUNTDATA.  This means that if a caller were to call
do_kern_mount with only about 10 bytes of options, they would get passed
here and then we would corrupt PAGE_SIZE - 10 bytes of memory (with all
zeros.)

Currently it appears all in kernel FS's use one page of data so this has
not been a problem.  An out of kernel FS did just what is described above
and it would almost always panic shortly after they tried to mount.  From
looking else where in the kernel it is obvious that this string of data
must always be null terminated.  (See example in do_mount where it always
zeros the last byte.) Thus I suggest we use strcpy in place of copy_page.
In this way we make sure the amount we copy is always less than or equal to
the amount we received and since do_mount is zeroing the last byte this
should be safe for all.

Signed-off-by: Eric Paris 
Cc: Stephen Smalley 
Acked-by: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] selinux: kfree cleanup

2005-06-25T23:25:00+00:00

kfree(NULL) is legal.

Signed-off-by: Jesper Juhl 
Acked-by: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] RCU: clean up a few remaining synchronize_kernel() calls

2005-06-25T23:24:38+00:00

2.6.12-rc6-mm1 has a few remaining synchronize_kernel()s, some (but not
all) in comments.  This patch changes these synchronize_kernel() calls (and
comments) to synchronize_rcu() or synchronize_sched() as follows:

- arch/x86_64/kernel/mce.c mce_read(): change to synchronize_sched() to
  handle races with machine-check exceptions (synchronize_rcu() would not cut
  it given RCU implementations intended for hardcore realtime use.

- drivers/input/serio/i8042.c i8042_stop(): change to synchronize_sched() to
  handle races with i8042_interrupt() interrupt handler.  Again,
  synchronize_rcu() would not cut it given RCU implementations intended for
  hardcore realtime use.

- include/*/kdebug.h comments: change to synchronize_sched() to handle races
  with NMIs.  As before, synchronize_rcu() would not cut it...

- include/linux/list.h comment: change to synchronize_rcu(), since this
  comment is for list_del_rcu().

- security/keys/key.c unregister_key_type(): change to synchronize_rcu(),
  since this is interacting with RCU read side.

- security/keys/process_keys.c install_session_keyring(): change to
  synchronize_rcu(), since this is interacting with RCU read side.

Signed-off-by: "Paul E. McKenney" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] selinux: add executable heap check

2005-06-25T23:24:26+00:00

This patch,based on sample code by Roland McGrath, adds an execheap
permission check that controls the ability to make the heap executable so
that this can be prevented in almost all cases (the X server is presently
an exception, but this will hopefully be resolved in the future) so that
even programs with execmem permission will need to have the anonymous
memory mapped in order to make it executable.

The only reason that we use a permission check for such restriction (vs.
making it unconditional) is that the X module loader presently needs it; it
could possibly be made unconditional in the future when X is changed.

The policy patch for the execheap permission is available at:
http://pearls.tuxedo-es.org/patches/selinux/policy-execheap.patch

Signed-off-by: Lorenzo Hernandez Garcia-Hierro 
Acked-by: James Morris 
Acked-by:  Stephen Smalley 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds