Update SELinux to cause the keycreate process attribute held in
/proc/self/attr/keycreate to be inherited across a fork and reset upon
execve. This is consistent with the handling of the other process
attributes provided by SELinux and also makes it simpler to adapt logon
programs to properly handle the keycreate attribute.
Signed-off-by: Michael LeMay <[email protected]>
Signed-off-by: David Howells <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Acked-by: James Morris <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Add a /proc/<pid>/attr/keycreate entry that stores the appropriate context for
newly-created keys. Modify the selinux_key_alloc hook to make use of the new
entry. Update the flask headers to include a new "setkeycreate" permission
for processes. Update the flask headers to include a new "create" permission
for keys. Use the create permission to restrict which SIDs each task can
assign to newly-created keys. Add a new parameter to the security hook
"security_key_alloc" to indicate whether it is being invoked by the kernel, or
from userspace. If it is being invoked by the kernel, the security hook
should never fail. Update the documentation to reflect these changes.
Signed-off-by: Michael LeMay <[email protected]>
Signed-off-by: James Morris <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Restrict /proc/keys such that only those keys to which the current task is
granted View permission are presented.
The documentation is also updated to reflect these changes.
Signed-off-by: Michael LeMay <[email protected]>
Signed-off-by: James Morris <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Cause key_alloc_serial() to generate key serial numbers randomly rather than
in linear sequence.
Using an linear sequence permits a covert communication channel to be
established, in which one process can communicate with another by creating or
not creating new keys within a certain timeframe. The second process can
probe for the expected next key serial number and judge its existence by the
error returned.
This is a problem as the serial number namespace is globally shared between
all tasks, regardless of their context.
For more information on this topic, this old TCSEC guide is recommended:
http://www.radium.ncsc.mil/tpep/library/rainbow/NCSC-TG-030.html
Signed-off-by: Michael LeMay <[email protected]>
Signed-off-by: James Morris <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Introduce SELinux hooks to support the access key retention subsystem
within the kernel. Incorporate new flask headers from a modified version
of the SELinux reference policy, with support for the new security class
representing retained keys. Extend the "key_alloc" security hook with a
task parameter representing the intended ownership context for the key
being allocated. Attach security information to root's default keyrings
within the SELinux initialization routine.
Has passed David's testsuite.
Signed-off-by: Michael LeMay <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: James Morris <[email protected]>
Acked-by: Chris Wright <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Michael LeMay