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* SELinux: Auto-generate security_is_socket_classHarry Ciao2011-03-03
| | | | | | | | | | | The security_is_socket_class() is auto-generated by genheaders based on classmap.h to reduce maintenance effort when a new class is defined in SELinux kernel. The name for any socket class should be suffixed by "socket" and doesn't contain more than one substr of "socket". Signed-off-by: Harry Ciao <qingtao.cao@windriver.com> Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
* selinux: drop unused packet flow permissionsEric Paris2011-02-25
| | | | | | | | | These permissions are not used and can be dropped in the kernel definitions. Suggested-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
* SELinux: Use dentry name in new object labelingEric Paris2011-02-01
| | | | | | | | | | | | | | | Currently SELinux has rules which label new objects according to 3 criteria. The label of the process creating the object, the label of the parent directory, and the type of object (reg, dir, char, block, etc.) This patch adds a 4th criteria, the dentry name, thus we can distinguish between creating a file in an etc_t directory called shadow and one called motd. There is no file globbing, regex parsing, or anything mystical. Either the policy exactly (strcmp) matches the dentry name of the object or it doesn't. This patch has no changes from today if policy does not implement the new rules. Signed-off-by: Eric Paris <eparis@redhat.com>
* security: Define CAP_SYSLOGSerge E. Hallyn2010-11-28
| | | | | | | | | | | | | | | | | | | | | | | | Privileged syslog operations currently require CAP_SYS_ADMIN. Split this off into a new CAP_SYSLOG privilege which we can sanely take away from a container through the capability bounding set. With this patch, an lxc container can be prevented from messing with the host's syslog (i.e. dmesg -c). Changelog: mar 12 2010: add selinux capability2:cap_syslog perm Changelog: nov 22 2010: . port to new kernel . add a WARN_ONCE if userspace isn't using CAP_SYSLOG Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Acked-by: Andrew G. Morgan <morgan@kernel.org> Acked-By: Kees Cook <kees.cook@canonical.com> Cc: James Morris <jmorris@namei.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: "Christopher J. PeBenito" <cpebenito@tresys.com> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: allow userspace to read policy back out of the kernelEric Paris2010-10-20
| | | | | | | | | | There is interest in being able to see what the actual policy is that was loaded into the kernel. The patch creates a new selinuxfs file /selinux/policy which can be read by userspace. The actual policy that is loaded into the kernel will be written back out to userspace. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* secmark: make secmark object handling genericEric Paris2010-10-20
| | | | | | | | | | | | | Right now secmark has lots of direct selinux calls. Use all LSM calls and remove all SELinux specific knowledge. The only SELinux specific knowledge we leave is the mode. The only point is to make sure that other LSMs at least test this generic code before they assume it works. (They may also have to make changes if they do not represent labels as strings) Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Paul Moore <paul.moore@hp.com> Acked-by: Patrick McHardy <kaber@trash.net> Signed-off-by: James Morris <jmorris@namei.org>
* selinux: fix up style problem on /selinux/statusKaiGai Kohei2010-10-20
| | | | | | | | | | This patch fixes up coding-style problem at this commit: 4f27a7d49789b04404eca26ccde5f527231d01d5 selinux: fast status update interface (/selinux/status) Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Signed-off-by: James Morris <jmorris@namei.org>
* selinux: fast status update interface (/selinux/status)KaiGai Kohei2010-10-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch provides a new /selinux/status entry which allows applications read-only mmap(2). This region reflects selinux_kernel_status structure in kernel space. struct selinux_kernel_status { u32 length; /* length of this structure */ u32 sequence; /* sequence number of seqlock logic */ u32 enforcing; /* current setting of enforcing mode */ u32 policyload; /* times of policy reloaded */ u32 deny_unknown; /* current setting of deny_unknown */ }; When userspace object manager caches access control decisions provided by SELinux, it needs to invalidate the cache on policy reload and setenforce to keep consistency. However, the applications need to check the kernel state for each accesses on userspace avc, or launch a background worker process. In heuristic, frequency of invalidation is much less than frequency of making access control decision, so it is annoying to invoke a system call to check we don't need to invalidate the userspace cache. If we can use a background worker thread, it allows to receive invalidation messages from the kernel. But it requires us an invasive coding toward the base application in some cases; E.g, when we provide a feature performing with SELinux as a plugin module, it is unwelcome manner to launch its own worker thread from the module. If we could map /selinux/status to process memory space, application can know updates of selinux status; policy reload or setenforce. A typical application checks selinux_kernel_status::sequence when it tries to reference userspace avc. If it was changed from the last time when it checked userspace avc, it means something was updated in the kernel space. Then, the application can reset userspace avc or update current enforcing mode, without any system call invocations. This sequence number is updated according to the seqlock logic, so we need to wait for a while if it is odd number. Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Acked-by: Eric Paris <eparis@redhat.com> -- security/selinux/include/security.h | 21 ++++++ security/selinux/selinuxfs.c | 56 +++++++++++++++ security/selinux/ss/Makefile | 2 +- security/selinux/ss/services.c | 3 + security/selinux/ss/status.c | 129 +++++++++++++++++++++++++++++++++++ 5 files changed, 210 insertions(+), 1 deletions(-) Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: Move execmod to the common permsEric Paris2010-08-02
| | | | | | | | | | | | | | execmod "could" show up on non regular files and non chr files. The current implementation would actually make these checks against non-existant bits since the code assumes the execmod permission is same for all file types. To make this line up for chr files we had to define execute_no_trans and entrypoint permissions. These permissions are unreachable and only existed to to make FILE__EXECMOD and CHR_FILE__EXECMOD the same. This patch drops those needless perms as well. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* selinux: place open in the common file permsEric Paris2010-08-02
| | | | | | | | | kernel can dynamically remap perms. Drop the open lookup table and put open in the common file perms. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: special dontaudit for access checksEric Paris2010-08-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently there are a number of applications (nautilus being the main one) which calls access() on files in order to determine how they should be displayed. It is normal and expected that nautilus will want to see if files are executable or if they are really read/write-able. access() should return the real permission. SELinux policy checks are done in access() and can result in lots of AVC denials as policy denies RWX on files which DAC allows. Currently SELinux must dontaudit actual attempts to read/write/execute a file in order to silence these messages (and not flood the logs.) But dontaudit rules like that can hide real attacks. This patch addes a new common file permission audit_access. This permission is special in that it is meaningless and should never show up in an allow rule. Instead the only place this permission has meaning is in a dontaudit rule like so: dontaudit nautilus_t sbin_t:file audit_access With such a rule if nautilus just checks access() we will still get denied and thus userspace will still get the correct answer but we will not log the denial. If nautilus attempted to actually perform one of the forbidden actions (rather than just querying access(2) about it) we would still log a denial. This type of dontaudit rule should be used sparingly, as it could be a method for an attacker to probe the system permissions without detection. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* switch selinux delayed superblock handling to iterate_supers()Al Viro2010-05-21
| | | | | | ... kill their private list, while we are at it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* selinux: always call sk_security_struct sksecEric Paris2010-04-07
| | | | | | | | trying to grep everything that messes with a sk_security_struct isn't easy since we don't always call it sksec. Just rename everything sksec. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* Merge branch 'next-queue' into nextJames Morris2010-03-08
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| * selinux: const strings in tablesStephen Hemminger2010-03-07
| | | | | | | | | | | | | | | | Several places strings tables are used that should be declared const. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: James Morris <jmorris@namei.org>
* | selinux: allow MLS->non-MLS and vice versa upon policy reloadGuido Trentalancia2010-02-03
| | | | | | | | | | | | | | | | | | Allow runtime switching between different policy types (e.g. from a MLS/MCS policy to a non-MLS/non-MCS policy or viceversa). Signed-off-by: Guido Trentalancia <guido@trentalancia.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* | selinux: change the handling of unknown classesStephen Smalley2010-01-17
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | If allow_unknown==deny, SELinux treats an undefined kernel security class as an error condition rather than as a typical permission denial and thus does not allow permissions on undefined classes even when in permissive mode. Change the SELinux logic so that this case is handled as a typical permission denial, subject to the usual permissive mode and permissive domain handling. Also drop the 'requested' argument from security_compute_av() and helpers as it is a legacy of the original security server interface and is unused. Changes: - Handle permissive domains consistently by moving up the test for a permissive domain. - Make security_compute_av_user() consistent with security_compute_av(); the only difference now is that security_compute_av() performs mapping between the kernel-private class and permission indices and the policy values. In the userspace case, this mapping is handled by libselinux. - Moved avd_init inside the policy lock. Based in part on a patch by Paul Moore <paul.moore@hp.com>. Reported-by: Andrew Worsley <amworsley@gmail.com> Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov> Reviewed-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
* selinux: generate flask headers during kernel buildStephen Smalley2009-10-07
| | | | | | | | | | | Add a simple utility (scripts/selinux/genheaders) and invoke it to generate the kernel-private class and permission indices in flask.h and av_permissions.h automatically during the kernel build from the security class mapping definitions in classmap.h. Adding new kernel classes and permissions can then be done just by adding them to classmap.h. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* selinux: dynamic class/perm discoveryStephen Smalley2009-10-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* selinux: Support for the new TUN LSM hooksPaul Moore2009-08-31
| | | | | | | | | | | | | | | | 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: Paul Moore <paul.moore@hp.com> Acked-by: Eric Paris <eparis@parisplace.org> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: Convert avc_audit to use lsm_audit.hThomas Liu2009-08-16
| | | | | | | | | | | | | | | | | | | | | | | | | Convert avc_audit in security/selinux/avc.c to use lsm_audit.h, for better maintainability. - changed selinux to use common_audit_data instead of avc_audit_data - eliminated code in avc.c and used code from lsm_audit.h instead. Had to add a LSM_AUDIT_NO_AUDIT to lsm_audit.h so that avc_audit can call common_lsm_audit and do the pre and post callbacks without doing the actual dump. This makes it so that the patched version behaves the same way as the unpatched version. Also added a denied field to the selinux_audit_data private space, once again to make it so that the patched version behaves like the unpatched. I've tested and confirmed that AVCs look the same before and after this patch. Signed-off-by: Thomas Liu <tliu@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: add selinux_kernel_module_requestEric Paris2009-08-13
| | | | | | | | | | | 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 <eparis@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* Revert "SELinux: Convert avc_audit to use lsm_audit.h"James Morris2009-07-12
| | | | | | | | This reverts commit 8113a8d80f4c6a3dc3724b39b470f3fee9c426b6. The patch causes a stack overflow on my system during boot. Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: Convert avc_audit to use lsm_audit.hThomas Liu2009-07-12
| | | | | | | | | | | | | | | | Convert avc_audit in security/selinux/avc.c to use lsm_audit.h, for better maintainability and for less code duplication. - changed selinux to use common_audit_data instead of avc_audit_data - eliminated code in avc.c and used code from lsm_audit.h instead. I have tested to make sure that the avcs look the same before and after this patch. Signed-off-by: Thomas Liu <tliu@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* selinux: clean up avc node cache when disabling selinuxThomas Liu2009-06-24
| | | | | | | | | | Added a call to free the avc_node_cache when inside selinux_disable because it should not waste resources allocated during avc_init if SELinux is disabled and the cache will never be used. Signed-off-by: Thomas Liu <tliu@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* Merge branch 'master' into nextJames Morris2009-06-18
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| * SELinux: move SELINUX_MAGIC into magic.hEric Paris2009-05-18
| | | | | | | | | | | | | | | | | | The selinuxfs superblock magic is used inside the IMA code, but is being defined in two places and could someday get out of sync. This patch moves the declaration into magic.h so it is only done once. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
| * Permissive domain in userspace object managerKaiGai Kohei2009-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables applications to handle permissive domain correctly. Since the v2.6.26 kernel, SELinux has supported an idea of permissive domain which allows certain processes to work as if permissive mode, even if the global setting is enforcing mode. However, we don't have an application program interface to inform what domains are permissive one, and what domains are not. It means applications focuses on SELinux (XACE/SELinux, SE-PostgreSQL and so on) cannot handle permissive domain correctly. This patch add the sixth field (flags) on the reply of the /selinux/access interface which is used to make an access control decision from userspace. If the first bit of the flags field is positive, it means the required access control decision is on permissive domain, so application should allow any required actions, as the kernel doing. This patch also has a side benefit. The av_decision.flags is set at context_struct_compute_av(). It enables to check required permissions without read_lock(&policy_rwlock). Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Eric Paris <eparis@redhat.com> -- security/selinux/avc.c | 2 +- security/selinux/include/security.h | 4 +++- security/selinux/selinuxfs.c | 4 ++-- security/selinux/ss/services.c | 30 +++++------------------------- 4 files changed, 11 insertions(+), 29 deletions(-) Signed-off-by: James Morris <jmorris@namei.org>
* | Add audit messages on type boundary violationsKaiGai Kohei2009-06-18
|/ | | | | | | | | | | | | | | | | | | | | | | | | | The attached patch adds support to generate audit messages on two cases. The first one is a case when a multi-thread process tries to switch its performing security context using setcon(3), but new security context is not bounded by the old one. type=SELINUX_ERR msg=audit(1245311998.599:17): \ op=security_bounded_transition result=denied \ oldcontext=system_u:system_r:httpd_t:s0 \ newcontext=system_u:system_r:guest_webapp_t:s0 The other one is a case when security_compute_av() masked any permissions due to the type boundary violation. type=SELINUX_ERR msg=audit(1245312836.035:32): \ op=security_compute_av reason=bounds \ scontext=system_u:object_r:user_webapp_t:s0 \ tcontext=system_u:object_r:shadow_t:s0:c0 \ tclass=file perms=getattr,open Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* netlabel: Label incoming TCP connections correctly in SELinuxPaul Moore2009-03-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Paul Moore <paul.moore@hp.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: new permission between tty audit and audit socketEric Paris2009-03-05
| | | | | | | | | New selinux permission to separate the ability to turn on tty auditing from the ability to set audit rules. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: open perm for sock filesEric Paris2009-03-05
| | | | | | | | | | | | | | | | 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 <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: remove unused av.decided fieldEric Paris2009-02-13
| | | | | | | | | | | | | | | | It appears there was an intention to have the security server only decide certain permissions and leave other for later as some sort of a portential performance win. We are currently always deciding all 32 bits of permissions and this is a useless couple of branches and wasted space. This patch completely drops the av.decided concept. This in a 17% reduction in the time spent in avc_has_perm_noaudit based on oprofile sampling of a tbench benchmark. Signed-off-by: Eric Paris <eparis@redhat.com> Reviewed-by: Paul Moore <paul.moore@hp.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: Add new security mount option to indicate security label support.David P. Quigley2009-01-18
| | | | | | | | | | | | There is no easy way to tell if a file system supports SELinux security labeling. Because of this a new flag is being added to the super block security structure to indicate that the particular super block supports labeling. This flag is set for file systems using the xattr, task, and transition labeling methods unless that behavior is overridden by context mounts. Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@macbook.localdomain>
* SELinux: Condense super block security structure flags and cleanup necessary ↵David P. Quigley2009-01-18
| | | | | | | | | | | | | | | code. The super block security structure currently has three fields for what are essentially flags. The flags field is used for mount options while two other char fields are used for initialization and proc flags. These latter two fields are essentially bit fields since the only used values are 0 and 1. These fields have been collapsed into the flags field and new bit masks have been added for them. The code is also fixed to work with these new flags. Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@macbook.localdomain>
* SELinux: shrink sizeof av_inhert selinux_class_perm and contextEric Paris2009-01-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I started playing with pahole today and decided to put it against the selinux structures. Found we could save a little bit of space on x86_64 (and no harm on i686) just reorganizing some structs. Object size changes: av_inherit: 24 -> 16 selinux_class_perm: 48 -> 40 context: 80 -> 72 Admittedly there aren't many of av_inherit or selinux_class_perm's in the kernel (33 and 1 respectively) But the change to the size of struct context reverberate out a bit. I can get some hard number if they are needed, but I don't see why they would be. We do change which cacheline context->len and context->str would be on, but I don't see that as a problem since we are clearly going to have to load both if the context is to be of any value. I've run with the patch and don't seem to be having any problems. An example of what's going on using struct av_inherit would be: form: to: struct av_inherit { struct av_inherit { u16 tclass; const char **common_pts; const char **common_pts; u32 common_base; u32 common_base; u16 tclass; }; (notice all I did was move u16 tclass to the end of the struct instead of the beginning) Memory layout before the change: struct av_inherit { u16 tclass; /* 2 */ /* 6 bytes hole */ const char** common_pts; /* 8 */ u32 common_base; /* 4 */ /* 4 byes padding */ /* size: 24, cachelines: 1 */ /* sum members: 14, holes: 1, sum holes: 6 */ /* padding: 4 */ }; Memory layout after the change: struct av_inherit { const char ** common_pts; /* 8 */ u32 common_base; /* 4 */ u16 tclass; /* 2 */ /* 2 bytes padding */ /* size: 16, cachelines: 1 */ /* sum members: 14, holes: 0, sum holes: 0 */ /* padding: 2 */ }; Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* CRED: Add a kernel_service object class to SELinuxDavid Howells2008-11-13
| | | | | | | | | | | | | | | | | | | | 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 <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* CRED: Make execve() take advantage of copy-on-write credentialsDavid Howells2008-11-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make execve() take advantage of copy-on-write credentials, allowing it to set up the credentials in advance, and then commit the whole lot after the point of no return. This patch and the preceding patches have been tested with the LTP SELinux testsuite. This patch makes several logical sets of alteration: (1) execve(). The credential bits from struct linux_binprm are, for the most part, replaced with a single credentials pointer (bprm->cred). This means that all the creds can be calculated in advance and then applied at the point of no return with no possibility of failure. I would like to replace bprm->cap_effective with: cap_isclear(bprm->cap_effective) but this seems impossible due to special behaviour for processes of pid 1 (they always retain their parent's capability masks where normally they'd be changed - see cap_bprm_set_creds()). The following sequence of events now happens: (a) At the start of do_execve, the current task's cred_exec_mutex is locked to prevent PTRACE_ATTACH from obsoleting the calculation of creds that we make. (a) prepare_exec_creds() is then called to make a copy of the current task's credentials and prepare it. This copy is then assigned to bprm->cred. This renders security_bprm_alloc() and security_bprm_free() unnecessary, and so they've been removed. (b) The determination of unsafe execution is now performed immediately after (a) rather than later on in the code. The result is stored in bprm->unsafe for future reference. (c) prepare_binprm() is called, possibly multiple times. (i) This applies the result of set[ug]id binaries to the new creds attached to bprm->cred. Personality bit clearance is recorded, but now deferred on the basis that the exec procedure may yet fail. (ii) This then calls the new security_bprm_set_creds(). This should calculate the new LSM and capability credentials into *bprm->cred. This folds together security_bprm_set() and parts of security_bprm_apply_creds() (these two have been removed). Anything that might fail must be done at this point. (iii) bprm->cred_prepared is set to 1. bprm->cred_prepared is 0 on the first pass of the security calculations, and 1 on all subsequent passes. This allows SELinux in (ii) to base its calculations only on the initial script and not on the interpreter. (d) flush_old_exec() is called to commit the task to execution. This performs the following steps with regard to credentials: (i) Clear pdeath_signal and set dumpable on certain circumstances that may not be covered by commit_creds(). (ii) Clear any bits in current->personality that were deferred from (c.i). (e) install_exec_creds() [compute_creds() as was] is called to install the new credentials. This performs the following steps with regard to credentials: (i) Calls security_bprm_committing_creds() to apply any security requirements, such as flushing unauthorised files in SELinux, that must be done before the credentials are changed. This is made up of bits of security_bprm_apply_creds() and security_bprm_post_apply_creds(), both of which have been removed. This function is not allowed to fail; anything that might fail must have been done in (c.ii). (ii) Calls commit_creds() to apply the new credentials in a single assignment (more or less). Possibly pdeath_signal and dumpable should be part of struct creds. (iii) Unlocks the task's cred_replace_mutex, thus allowing PTRACE_ATTACH to take place. (iv) Clears The bprm->cred pointer as the credentials it was holding are now immutable. (v) Calls security_bprm_committed_creds() to apply any security alterations that must be done after the creds have been changed. SELinux uses this to flush signals and signal handlers. (f) If an error occurs before (d.i), bprm_free() will call abort_creds() to destroy the proposed new credentials and will then unlock cred_replace_mutex. No changes to the credentials will have been made. (2) LSM interface. A number of functions have been changed, added or removed: (*) security_bprm_alloc(), ->bprm_alloc_security() (*) security_bprm_free(), ->bprm_free_security() Removed in favour of preparing new credentials and modifying those. (*) security_bprm_apply_creds(), ->bprm_apply_creds() (*) security_bprm_post_apply_creds(), ->bprm_post_apply_creds() Removed; split between security_bprm_set_creds(), security_bprm_committing_creds() and security_bprm_committed_creds(). (*) security_bprm_set(), ->bprm_set_security() Removed; folded into security_bprm_set_creds(). (*) security_bprm_set_creds(), ->bprm_set_creds() New. The new credentials in bprm->creds should be checked and set up as appropriate. bprm->cred_prepared is 0 on the first call, 1 on the second and subsequent calls. (*) security_bprm_committing_creds(), ->bprm_committing_creds() (*) security_bprm_committed_creds(), ->bprm_committed_creds() New. Apply the security effects of the new credentials. This includes closing unauthorised files in SELinux. This function may not fail. When the former is called, the creds haven't yet been applied to the process; when the latter is called, they have. The former may access bprm->cred, the latter may not. (3) SELinux. SELinux has a number of changes, in addition to those to support the LSM interface changes mentioned above: (a) The bprm_security_struct struct has been removed in favour of using the credentials-under-construction approach. (c) flush_unauthorized_files() now takes a cred pointer and passes it on to inode_has_perm(), file_has_perm() and dentry_open(). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* Merge branch 'master' of ↵James Morris2008-10-10
|\ | | | | | | git://git.infradead.org/users/pcmoore/lblnet-2.6_next into next
| * selinux: Cache NetLabel secattrs in the socket's security structPaul Moore2008-10-10
| | | | | | | | | | | | | | | | | | | | | | | | Previous work enabled the use of address based NetLabel selectors, which while highly useful, brought the potential for additional per-packet overhead when used. This patch attempts to mitigate some of that overhead by caching the NetLabel security attribute struct within the SELinux socket security structure. This should help eliminate the need to recreate the NetLabel secattr structure for each packet resulting in less overhead. Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: James Morris <jmorris@namei.org>
| * selinux: Set socket NetLabel based on connection endpointPaul Moore2008-10-10
| | | | | | | | | | | | | | | | | | | | | | | | Previous work enabled the use of address based NetLabel selectors, which while highly useful, brought the potential for additional per-packet overhead when used. This patch attempts to solve that by applying NetLabel socket labels when sockets are connect()'d. This should alleviate the per-packet NetLabel labeling for all connected sockets (yes, it even works for connected DGRAM sockets). Signed-off-by: Paul Moore <paul.moore@hp.com> Reviewed-by: James Morris <jmorris@namei.org>
| * netlabel: Add functionality to set the security attributes of a packetPaul Moore2008-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch builds upon the new NetLabel address selector functionality by providing the NetLabel KAPI and CIPSO engine support needed to enable the new packet-based labeling. The only new addition to the NetLabel KAPI at this point is shown below: * int netlbl_skbuff_setattr(skb, family, secattr) ... and is designed to be called from a Netfilter hook after the packet's IP header has been populated such as in the FORWARD or LOCAL_OUT hooks. This patch also provides the necessary SELinux hooks to support this new functionality. Smack support is not currently included due to uncertainty regarding the permissions needed to expand the Smack network access controls. Signed-off-by: Paul Moore <paul.moore@hp.com> Reviewed-by: James Morris <jmorris@namei.org>
| * selinux: Fix missing calls to netlbl_skbuff_err()Paul Moore2008-10-10
| | | | | | | | | | | | | | | | | | At some point I think I messed up and dropped the calls to netlbl_skbuff_err() which are necessary for CIPSO to send error notifications to remote systems. This patch re-introduces the error handling calls into the SELinux code. Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: James Morris <jmorris@namei.org>
* | SELinux: add boundary support and thread context assignmentKaiGai Kohei2008-08-28
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The purpose of this patch is to assign per-thread security context under a constraint. It enables multi-threaded server application to kick a request handler with its fair security context, and helps some of userspace object managers to handle user's request. When we assign a per-thread security context, it must not have wider permissions than the original one. Because a multi-threaded process shares a single local memory, an arbitary per-thread security context also means another thread can easily refer violated information. The constraint on a per-thread security context requires a new domain has to be equal or weaker than its original one, when it tries to assign a per-thread security context. Bounds relationship between two types is a way to ensure a domain can never have wider permission than its bounds. We can define it in two explicit or implicit ways. The first way is using new TYPEBOUNDS statement. It enables to define a boundary of types explicitly. The other one expand the concept of existing named based hierarchy. If we defines a type with "." separated name like "httpd_t.php", toolchain implicitly set its bounds on "httpd_t". This feature requires a new policy version. The 24th version (POLICYDB_VERSION_BOUNDARY) enables to ship them into kernel space, and the following patch enables to handle it. Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* Revert "SELinux: allow fstype unknown to policy to use xattrs if present"James Morris2008-07-15
| | | | | | | | | This reverts commit 811f3799279e567aa354c649ce22688d949ac7a9. From Eric Paris: "Please drop this patch for now. It deadlocks on ntfs-3g. I need to rework it to handle fuse filesystems better. (casey was right)"
* SELinux: allow fstype unknown to policy to use xattrs if presentEric Paris2008-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently if a FS is mounted for which SELinux policy does not define an fs_use_* that FS will either be genfs labeled or not labeled at all. This decision is based on the existence of a genfscon rule in policy and is irrespective of the capabilities of the filesystem itself. This patch allows the kernel to check if the filesystem supports security xattrs and if so will use those if there is no fs_use_* rule in policy. An fstype with a no fs_use_* rule but with a genfs rule will use xattrs if available and will follow the genfs rule. This can be particularly interesting for things like ecryptfs which actually overlays a real underlying FS. If we define excryptfs in policy to use xattrs we will likely get this wrong at times, so with this path we just don't need to define it! Overlay ecryptfs on top of NFS with no xattr support: SELinux: initialized (dev ecryptfs, type ecryptfs), uses genfs_contexts Overlay ecryptfs on top of ext4 with xattr support: SELinux: initialized (dev ecryptfs, type ecryptfs), uses xattr It is also useful as the kernel adds new FS we don't need to add them in policy if they support xattrs and that is how we want to handle them. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: remove inherit field from inode_security_structJames Morris2008-07-14
| | | | | | | Remove inherit field from inode_security_struct, per Stephen Smalley: "Let's just drop inherit altogether - dead field." Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: reorder inode_security_struct to increase objs/slab on 64bitRichard Kennedy2008-07-14
| | | | | | | | | reorder inode_security_struct to remove padding on 64 bit builds size reduced from 72 to 64 bytes increasing objects per slab to 64. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: James Morris <jmorris@namei.org>
* SELinux: keep the code clean formating and syntaxEric Paris2008-07-14
| | | | | | | | | | | | | | | Formatting and syntax changes whitespace, tabs to spaces, trailing space put open { on same line as struct def remove unneeded {} after if statements change printk("Lu") to printk("llu") convert asm/uaccess.h to linux/uaacess.h includes remove unnecessary asm/bug.h includes convert all users of simple_strtol to strict_strtol Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* selinux: support deferred mapping of contextsStephen Smalley2008-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce SELinux support for deferred mapping of security contexts in the SID table upon policy reload, and use this support for inode security contexts when the context is not yet valid under the current policy. Only processes with CAP_MAC_ADMIN + mac_admin permission in policy can set undefined security contexts on inodes. Inodes with such undefined contexts are treated as having the unlabeled context until the context becomes valid upon a policy reload that defines the context. Context invalidation upon policy reload also uses this support to save the context information in the SID table and later recover it upon a subsequent policy reload that defines the context again. This support is to enable package managers and similar programs to set down file contexts unknown to the system policy at the time the file is created in order to better support placing loadable policy modules in packages and to support build systems that need to create images of different distro releases with different policies w/o requiring all of the contexts to be defined or legal in the build host policy. With this patch applied, the following sequence is possible, although in practice it is recommended that this permission only be allowed to specific program domains such as the package manager. # rmdir baz # rm bar # touch bar # chcon -t foo_exec_t bar # foo_exec_t is not yet defined chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument # mkdir -Z system_u:object_r:foo_exec_t baz mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument # cat setundefined.te policy_module(setundefined, 1.0) require { type unconfined_t; type unlabeled_t; } files_type(unlabeled_t) allow unconfined_t self:capability2 mac_admin; # make -f /usr/share/selinux/devel/Makefile setundefined.pp # semodule -i setundefined.pp # chcon -t foo_exec_t bar # foo_exec_t is not yet defined # mkdir -Z system_u:object_r:foo_exec_t baz # ls -Zd bar baz -rw-r--r-- root root system_u:object_r:unlabeled_t bar drwxr-xr-x root root system_u:object_r:unlabeled_t baz # cat foo.te policy_module(foo, 1.0) type foo_exec_t; files_type(foo_exec_t) # make -f /usr/share/selinux/devel/Makefile foo.pp # semodule -i foo.pp # defines foo_exec_t # ls -Zd bar baz -rw-r--r-- root root user_u:object_r:foo_exec_t bar drwxr-xr-x root root system_u:object_r:foo_exec_t baz # semodule -r foo # ls -Zd bar baz -rw-r--r-- root root system_u:object_r:unlabeled_t bar drwxr-xr-x root root system_u:object_r:unlabeled_t baz # semodule -i foo.pp # ls -Zd bar baz -rw-r--r-- root root user_u:object_r:foo_exec_t bar drwxr-xr-x root root system_u:object_r:foo_exec_t baz # semodule -r setundefined foo # chcon -t foo_exec_t bar # no longer defined and not allowed chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument # rmdir baz # mkdir -Z system_u:object_r:foo_exec_t baz mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>