lwn.git/security/selinux/include/av_perm_to_string.h, branch v3.0.56

selinux: dynamic class/perm discovery

2009-10-07T10:56:42+00:00

Modify SELinux to dynamically discover class and permission values upon policy load, based on the dynamic object class/perm discovery logic from libselinux. A mapping is created between kernel-private class and permission indices used outside the security server and the policy values used within the security server. The mappings are only applied upon kernel-internal computations; similar mappings for the private indices of userspace object managers is handled on a per-object manager basis by the userspace AVC. The interfaces for compute_av and transition_sid are split for kernel vs. userspace; the userspace functions are distinguished by a _user suffix. The kernel-private class indices are no longer tied to the policy values and thus do not need to skip indices for userspace classes; thus the kernel class index values are compressed. The flask.h definitions were regenerated by deleting the userspace classes from refpolicy's definitions and then regenerating the headers. Going forward, we can just maintain the flask.h, av_permissions.h, and classmap.h definitions separately from policy as they are no longer tied to the policy values. The next patch introduces a utility to automate generation of flask.h and av_permissions.h from the classmap.h definitions. The older kernel class and permission string tables are removed and replaced by a single security class mapping table that is walked at policy load to generate the mapping. The old kernel class validation logic is completely replaced by the mapping logic. The handle unknown logic is reworked. reject_unknown=1 is handled when the mappings are computed at policy load time, similar to the old handling by the class validation logic. allow_unknown=1 is handled when computing and mapping decisions - if the permission was not able to be mapped (i.e. undefined, mapped to zero), then it is automatically added to the allowed vector. If the class was not able to be mapped (i.e. undefined, mapped to zero), then all permissions are allowed for it if allow_unknown=1. avc_audit leverages the new security class mapping table to lookup the class and permission names from the kernel-private indices. The mdp program is updated to use the new table when generating the class definitions and allow rules for a minimal boot policy for the kernel. It should be noted that this policy will not include any userspace classes, nor will its policy index values for the kernel classes correspond with the ones in refpolicy (they will instead match the kernel-private indices). Signed-off-by: Stephen Smalley Signed-off-by: James Morris

SELinux: add selinux_kernel_module_request

2009-08-14T01:18:40+00:00

This patch adds a new selinux hook so SELinux can arbitrate if a given process should be allowed to trigger a request for the kernel to try to load a module. This is a different operation than a process trying to load a module itself, which is already protected by CAP_SYS_MODULE. Signed-off-by: Eric Paris Acked-by: Serge Hallyn Signed-off-by: James Morris

SELinux: new permission between tty audit and audit socket

2009-03-05T21:50:21+00:00

New selinux permission to separate the ability to turn on tty auditing from the ability to set audit rules. Signed-off-by: Eric Paris Acked-by: Stephen Smalley Signed-off-by: James Morris

SELinux: open perm for sock files

2009-03-05T21:50:18+00:00

When I did open permissions I didn't think any sockets would have an open. Turns out AF_UNIX sockets can have an open when they are bound to the filesystem namespace. This patch adds a new SOCK_FILE__OPEN permission. It's safe to add this as the open perms are already predicated on capabilities and capabilities means we have unknown perm handling so systems should be as backwards compatible as the policy wants them to be. https://bugzilla.redhat.com/show_bug.cgi?id=475224 Signed-off-by: Eric Paris Acked-by: Stephen Smalley Signed-off-by: James Morris

CRED: Add a kernel_service object class to SELinux

2008-11-13T23:39:27+00:00

Add a 'kernel_service' object class to SELinux and give this object class two access vectors: 'use_as_override' and 'create_files_as'. The first vector is used to grant a process the right to nominate an alternate process security ID for the kernel to use as an override for the SELinux subjective security when accessing stuff on behalf of another process. For example, CacheFiles when accessing the cache on behalf on a process accessing an NFS file needs to use a subjective security ID appropriate to the cache rather then the one the calling process is using. The cachefilesd daemon will nominate the security ID to be used. The second vector is used to grant a process the right to nominate a file creation label for a kernel service to use. Signed-off-by: David Howells Signed-off-by: James Morris

SELinux: create new open permission

2008-04-18T10:26:06+00:00

Adds a new open permission inside SELinux when 'opening' a file. The idea is that opening a file and reading/writing to that file are not the same thing. Its different if a program had its stdout redirected to /tmp/output than if the program tried to directly open /tmp/output. This should allow policy writers to more liberally give read/write permissions across the policy while still blocking many design and programing flaws SELinux is so good at catching today. Signed-off-by: Eric Paris Acked-by: Stephen Smalley Reviewed-by: Paul Moore Signed-off-by: James Morris

selinux: support 64-bit capabilities

2008-02-11T09:30:02+00:00

Fix SELinux to handle 64-bit capabilities correctly, and to catch future extensions of capabilities beyond 64 bits to ensure that SELinux is properly updated. Signed-off-by: Stephen Smalley Signed-off-by: James Morris

SELinux: Add a new peer class and permissions to the Flask definitions

2008-01-29T21:17:24+00:00

Add additional Flask definitions to support the new "peer" object class and additional permissions to the netif, node, and packet object classes. Also, bring the kernel Flask definitions up to date with the Fedora SELinux policies by adding the "flow_in" and "flow_out" permissions to the "packet" class. Signed-off-by: Paul Moore Signed-off-by: James Morris

security: Protection for exploiting null dereference using mmap

2007-07-12T02:52:29+00:00

Add a new security check on mmap operations to see if the user is attempting to mmap to low area of the address space. The amount of space protected is indicated by the new proc tunable /proc/sys/vm/mmap_min_addr and defaults to 0, preserving existing behavior. This patch uses a new SELinux security class "memprotect." Policy already contains a number of allow rules like a_t self:process * (unconfined_t being one of them) which mean that putting this check in the process class (its best current fit) would make it useless as all user processes, which we also want to protect against, would be allowed. By taking the memprotect name of the new class it will also make it possible for us to move some of the other memory protect permissions out of 'process' and into the new class next time we bump the policy version number (which I also think is a good future idea) Acked-by: Stephen Smalley Acked-by: Chris Wright Signed-off-by: Eric Paris Signed-off-by: James Morris

selinux: remove userland security class and permission definitions

2007-04-26T05:35:58+00:00

Remove userland security class and permission definitions from the kernel as the kernel only needs to use and validate its own class and permission definitions and userland definitions may change. Signed-off-by: Stephen Smalley Signed-off-by: James Morris