summaryrefslogtreecommitdiff
path: root/security/selinux/hooks.c
AgeCommit message (Collapse)Author
2022-04-15LSM: general protection fault in legacy_parse_paramCasey Schaufler
[ Upstream commit ecff30575b5ad0eda149aadad247b7f75411fd47 ] The usual LSM hook "bail on fail" scheme doesn't work for cases where a security module may return an error code indicating that it does not recognize an input. In this particular case Smack sees a mount option that it recognizes, and returns 0. A call to a BPF hook follows, which returns -ENOPARAM, which confuses the caller because Smack has processed its data. The SELinux hook incorrectly returns 1 on success. There was a time when this was correct, however the current expectation is that it return 0 on success. This is repaired. Reported-by: syzbot+d1e3b1d92d25abf97943@syzkaller.appspotmail.com Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27selinux: fix potential memleak in selinux_add_opt()Bernard Zhao
[ Upstream commit 2e08df3c7c4e4e74e3dd5104c100f0bf6288aaa8 ] This patch try to fix potential memleak in error branch. Fixes: ba6418623385 ("selinux: new helper - selinux_add_opt()") Signed-off-by: Bernard Zhao <bernard@vivo.com> [PM: tweak the subject line, add Fixes tag] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-05selinux: initialize proto variable in selinux_ip_postroute_compat()Tom Rix
commit 732bc2ff080c447f8524f40c970c481f5da6eed3 upstream. Clang static analysis reports this warning hooks.c:5765:6: warning: 4th function call argument is an uninitialized value if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ selinux_parse_skb() can return ok without setting proto. The later call to selinux_xfrm_postroute_last() does an early check of proto and can return ok if the garbage proto value matches. So initialize proto. Cc: stable@vger.kernel.org Fixes: eef9b41622f2 ("selinux: cleanup selinux_xfrm_sock_rcv_skb() and selinux_xfrm_postroute_last()") Signed-off-by: Tom Rix <trix@redhat.com> [PM: typo/spelling and checkpatch.pl description fixes] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-17binder: use cred instead of task for selinux checksTodd Kjos
commit 52f88693378a58094c538662ba652aff0253c4fe upstream. Since binder was integrated with selinux, it has passed 'struct task_struct' associated with the binder_proc to represent the source and target of transactions. The conversion of task to SID was then done in the hook implementations. It turns out that there are race conditions which can result in an incorrect security context being used. Fix by using the 'struct cred' saved during binder_open and pass it to the selinux subsystem. Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables) Fixes: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.") Suggested-by: Jann Horn <jannh@google.com> Signed-off-by: Todd Kjos <tkjos@google.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handlingPaul Moore
[ Upstream commit 200ea5a2292dc444a818b096ae6a32ba3caa51b9 ] A previous fix, commit 83370b31a915 ("selinux: fix error initialization in inode_doinit_with_dentry()"), changed how failures were handled before a SELinux policy was loaded. Unfortunately that patch was potentially problematic for two reasons: it set the isec->initialized state without holding a lock, and it didn't set the inode's SELinux label to the "default" for the particular filesystem. The later can be a problem if/when a later attempt to revalidate the inode fails and SELinux reverts to the existing inode label. This patch should restore the default inode labeling that existed before the original fix, without affecting the LABEL_INVALID marking such that revalidation will still be attempted in the future. Fixes: 83370b31a915 ("selinux: fix error initialization in inode_doinit_with_dentry()") Reported-by: Sven Schnelle <svens@linux.ibm.com> Tested-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30selinux: fix error initialization in inode_doinit_with_dentry()Tianyue Ren
[ Upstream commit 83370b31a915493231e5b9addc72e4bef69f8d31 ] Mark the inode security label as invalid if we cannot find a dentry so that we will retry later rather than marking it initialized with the unlabeled SID. Fixes: 9287aed2ad1f ("selinux: Convert isec->lock into a spinlock") Signed-off-by: Tianyue Ren <rentianyue@kylinos.cn> [PM: minor comment tweaks] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01selinux: allow labeling before policy is loadedJonathan Lebon
[ Upstream commit 3e3e24b42043eceb97ed834102c2d094dfd7aaa6 ] Currently, the SELinux LSM prevents one from setting the `security.selinux` xattr on an inode without a policy first being loaded. However, this restriction is problematic: it makes it impossible to have newly created files with the correct label before actually loading the policy. This is relevant in distributions like Fedora, where the policy is loaded by systemd shortly after pivoting out of the initrd. In such instances, all files created prior to pivoting will be unlabeled. One then has to relabel them after pivoting, an operation which inherently races with other processes trying to access those same files. Going further, there are use cases for creating the entire root filesystem on first boot from the initrd (e.g. Container Linux supports this today[1], and we'd like to support it in Fedora CoreOS as well[2]). One can imagine doing this in two ways: at the block device level (e.g. laying down a disk image), or at the filesystem level. In the former, labeling can simply be part of the image. But even in the latter scenario, one still really wants to be able to set the right labels when populating the new filesystem. This patch enables this by changing behaviour in the following two ways: 1. allow `setxattr` if we're not initialized 2. don't try to set the in-core inode SID if we're not initialized; instead leave it as `LABEL_INVALID` so that revalidation may be attempted at a later time Note the first hunk of this patch is mostly the same as a previously discussed one[3], though it was part of a larger series which wasn't accepted. [1] https://coreos.com/os/docs/latest/root-filesystem-placement.html [2] https://github.com/coreos/fedora-coreos-tracker/issues/94 [3] https://www.spinics.net/lists/linux-initramfs/msg04593.html Co-developed-by: Victor Kamensky <kamensky@cisco.com> Signed-off-by: Victor Kamensky <kamensky@cisco.com> Signed-off-by: Jonathan Lebon <jlebon@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-06selinux: properly handle multiple messages in selinux_netlink_send()Paul Moore
commit fb73974172ffaaf57a7c42f35424d9aece1a5af6 upstream. Fix the SELinux netlink_send hook to properly handle multiple netlink messages in a single sk_buff; each message is parsed and subject to SELinux access control. Prior to this patch, SELinux only inspected the first message in the sk_buff. Cc: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14selinux: fall back to ref-walk if audit is requiredStephen Smalley
commit 0188d5c025ca8fe756ba3193bd7d150139af5a88 upstream. commit bda0be7ad994 ("security: make inode_follow_link RCU-walk aware") passed down the rcu flag to the SELinux AVC, but failed to adjust the test in slow_avc_audit() to also return -ECHILD on LSM_AUDIT_DATA_DENTRY. Previously, we only returned -ECHILD if generating an audit record with LSM_AUDIT_DATA_INODE since this was only relevant from inode_permission. Move the handling of MAY_NOT_BLOCK to avc_audit() and its inlined equivalent in selinux_inode_permission() immediately after we determine that audit is required, and always fall back to ref-walk in this case. Fixes: bda0be7ad994 ("security: make inode_follow_link RCU-walk aware") Reported-by: Will Deacon <will@kernel.org> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14selinux: fix regression introduced by move_mount(2) syscallStephen Smalley
commit 98aa00345de54b8340dc2ddcd87f446d33387b5e upstream. commit 2db154b3ea8e ("vfs: syscall: Add move_mount(2) to move mounts around") introduced a new move_mount(2) system call and a corresponding new LSM security_move_mount hook but did not implement this hook for any existing LSM. This creates a regression for SELinux with respect to consistent checking of mounts; the existing selinux_mount hook checks mounton permission to the mount point path. Provide a SELinux hook implementation for move_mount that applies this same check for consistency. In the future we may wish to add a new move_mount filesystem permission and check as well, but this addresses the immediate regression. Fixes: 2db154b3ea8e ("vfs: syscall: Add move_mount(2) to move mounts around") Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14selinux: revert "stop passing MAY_NOT_BLOCK to the AVC upon follow_link"Stephen Smalley
commit 1a37079c236d55fb31ebbf4b59945dab8ec8764c upstream. This reverts commit e46e01eebbbc ("selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_link"). The correct fix is to instead fall back to ref-walk if audit is required irrespective of the specific audit data type. This is done in the next commit. Fixes: e46e01eebbbc ("selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_link") Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-23Merge tag 'selinux-pr-20190917' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: - Add LSM hooks, and SELinux access control hooks, for dnotify, fanotify, and inotify watches. This has been discussed with both the LSM and fs/notify folks and everybody is good with these new hooks. - The LSM stacking changes missed a few calls to current_security() in the SELinux code; we fix those and remove current_security() for good. - Improve our network object labeling cache so that we always return the object's label, even when under memory pressure. Previously we would return an error if we couldn't allocate a new cache entry, now we always return the label even if we can't create a new cache entry for it. - Convert the sidtab atomic_t counter to a normal u32 with READ/WRITE_ONCE() and memory barrier protection. - A few patches to policydb.c to clean things up (remove forward declarations, long lines, bad variable names, etc) * tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: lsm: remove current_security() selinux: fix residual uses of current_security() for the SELinux blob selinux: avoid atomic_t usage in sidtab fanotify, inotify, dnotify, security: add security hook for fs notifications selinux: always return a secid from the network caches if we find one selinux: policydb - rename type_val_to_struct_array selinux: policydb - fix some checkpatch.pl warnings selinux: shuffle around policydb.c to get rid of forward declarations
2019-09-04selinux: fix residual uses of current_security() for the SELinux blobStephen Smalley
We need to use selinux_cred() to fetch the SELinux cred blob instead of directly using current->security or current_security(). There were a couple of lingering uses of current_security() in the SELinux code that were apparently missed during the earlier conversions. IIUC, this would only manifest as a bug if multiple security modules including SELinux are enabled and SELinux is not first in the lsm order. After this change, there appear to be no other users of current_security() in-tree; perhaps we should remove it altogether. Fixes: bbd3662a8348 ("Infrastructure management of the cred security blob") Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-08-12fanotify, inotify, dnotify, security: add security hook for fs notificationsAaron Goidel
As of now, setting watches on filesystem objects has, at most, applied a check for read access to the inode, and in the case of fanotify, requires CAP_SYS_ADMIN. No specific security hook or permission check has been provided to control the setting of watches. Using any of inotify, dnotify, or fanotify, it is possible to observe, not only write-like operations, but even read access to a file. Modeling the watch as being merely a read from the file is insufficient for the needs of SELinux. This is due to the fact that read access should not necessarily imply access to information about when another process reads from a file. Furthermore, fanotify watches grant more power to an application in the form of permission events. While notification events are solely, unidirectional (i.e. they only pass information to the receiving application), permission events are blocking. Permission events make a request to the receiving application which will then reply with a decision as to whether or not that action may be completed. This causes the issue of the watching application having the ability to exercise control over the triggering process. Without drawing a distinction within the permission check, the ability to read would imply the greater ability to control an application. Additionally, mount and superblock watches apply to all files within the same mount or superblock. Read access to one file should not necessarily imply the ability to watch all files accessed within a given mount or superblock. In order to solve these issues, a new LSM hook is implemented and has been placed within the system calls for marking filesystem objects with inotify, fanotify, and dnotify watches. These calls to the hook are placed at the point at which the target path has been resolved and are provided with the path struct, the mask of requested notification events, and the type of object on which the mark is being set (inode, superblock, or mount). The mask and obj_type have already been translated into common FS_* values shared by the entirety of the fs notification infrastructure. The path struct is passed rather than just the inode so that the mount is available, particularly for mount watches. This also allows for use of the hook by pathname-based security modules. However, since the hook is intended for use even by inode based security modules, it is not placed under the CONFIG_SECURITY_PATH conditional. Otherwise, the inode-based security modules would need to enable all of the path hooks, even though they do not use any of them. This only provides a hook at the point of setting a watch, and presumes that permission to set a particular watch implies the ability to receive all notification about that object which match the mask. This is all that is required for SELinux. If other security modules require additional hooks or infrastructure to control delivery of notification, these can be added by them. It does not make sense for us to propose hooks for which we have no implementation. The understanding that all notifications received by the requesting application are all strictly of a type for which the application has been granted permission shows that this implementation is sufficient in its coverage. Security modules wishing to provide complete control over fanotify must also implement a security_file_open hook that validates that the access requested by the watching application is authorized. Fanotify has the issue that it returns a file descriptor with the file mode specified during fanotify_init() to the watching process on event. This is already covered by the LSM security_file_open hook if the security module implements checking of the requested file mode there. Otherwise, a watching process can obtain escalated access to a file for which it has not been authorized. The selinux_path_notify hook implementation works by adding five new file permissions: watch, watch_mount, watch_sb, watch_reads, and watch_with_perm (descriptions about which will follow), and one new filesystem permission: watch (which is applied to superblock checks). The hook then decides which subset of these permissions must be held by the requesting application based on the contents of the provided mask and the obj_type. The selinux_file_open hook already checks the requested file mode and therefore ensures that a watching process cannot escalate its access through fanotify. The watch, watch_mount, and watch_sb permissions are the baseline permissions for setting a watch on an object and each are a requirement for any watch to be set on a file, mount, or superblock respectively. It should be noted that having either of the other two permissions (watch_reads and watch_with_perm) does not imply the watch, watch_mount, or watch_sb permission. Superblock watches further require the filesystem watch permission to the superblock. As there is no labeled object in view for mounts, there is no specific check for mount watches beyond watch_mount to the inode. Such a check could be added in the future, if a suitable labeled object existed representing the mount. The watch_reads permission is required to receive notifications from read-exclusive events on filesystem objects. These events include accessing a file for the purpose of reading and closing a file which has been opened read-only. This distinction has been drawn in order to provide a direct indication in the policy for this otherwise not obvious capability. Read access to a file should not necessarily imply the ability to observe read events on a file. Finally, watch_with_perm only applies to fanotify masks since it is the only way to set a mask which allows for the blocking, permission event. This permission is needed for any watch which is of this type. Though fanotify requires CAP_SYS_ADMIN, this is insufficient as it gives implicit trust to root, which we do not do, and does not support least privilege. Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-07-10Revert "Merge tag 'keys-acl-20190703' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" This reverts merge 0f75ef6a9cff49ff612f7ce0578bced9d0b38325 (and thus effectively commits 7a1ade847596 ("keys: Provide KEYCTL_GRANT_PERMISSION") 2e12256b9a76 ("keys: Replace uid/gid/perm permissions checking with an ACL") that the merge brought in). It turns out that it breaks booting with an encrypted volume, and Eric biggers reports that it also breaks the fscrypt tests [1] and loading of in-kernel X.509 certificates [2]. The root cause of all the breakage is likely the same, but David Howells is off email so rather than try to work it out it's getting reverted in order to not impact the rest of the merge window. [1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/ [2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/ Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/ Reported-by: Eric Biggers <ebiggers@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-08Merge branch 'next-integrity' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity updates from Mimi Zohar: "Bug fixes, code clean up, and new features: - IMA policy rules can be defined in terms of LSM labels, making the IMA policy dependent on LSM policy label changes, in particular LSM label deletions. The new environment, in which IMA-appraisal is being used, frequently updates the LSM policy and permits LSM label deletions. - Prevent an mmap'ed shared file opened for write from also being mmap'ed execute. In the long term, making this and other similar changes at the VFS layer would be preferable. - The IMA per policy rule template format support is needed for a couple of new/proposed features (eg. kexec boot command line measurement, appended signatures, and VFS provided file hashes). - Other than the "boot-aggregate" record in the IMA measuremeent list, all other measurements are of file data. Measuring and storing the kexec boot command line in the IMA measurement list is the first buffer based measurement included in the measurement list" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: integrity: Introduce struct evm_xattr ima: Update MAX_TEMPLATE_NAME_LEN to fit largest reasonable definition KEXEC: Call ima_kexec_cmdline to measure the boot command line args IMA: Define a new template field buf IMA: Define a new hook to measure the kexec boot command line arguments IMA: support for per policy rule template formats integrity: Fix __integrity_init_keyring() section mismatch ima: Use designated initializers for struct ima_event_data ima: use the lsm policy update notifier LSM: switch to blocking policy update notifiers x86/ima: fix the Kconfig dependency for IMA_ARCH_POLICY ima: Make arch_policy_entry static ima: prevent a file already mmap'ed write to be mmap'ed execute x86/ima: check EFI SetupMode too
2019-07-08Merge tag 'keys-acl-20190703' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull keyring ACL support from David Howells: "This changes the permissions model used by keys and keyrings to be based on an internal ACL by the following means: - Replace the permissions mask internally with an ACL that contains a list of ACEs, each with a specific subject with a permissions mask. Potted default ACLs are available for new keys and keyrings. ACE subjects can be macroised to indicate the UID and GID specified on the key (which remain). Future commits will be able to add additional subject types, such as specific UIDs or domain tags/namespaces. Also split a number of permissions to give finer control. Examples include splitting the revocation permit from the change-attributes permit, thereby allowing someone to be granted permission to revoke a key without allowing them to change the owner; also the ability to join a keyring is split from the ability to link to it, thereby stopping a process accessing a keyring by joining it and thus acquiring use of possessor permits. - Provide a keyctl to allow the granting or denial of one or more permits to a specific subject. Direct access to the ACL is not granted, and the ACL cannot be viewed" * tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: keys: Provide KEYCTL_GRANT_PERMISSION keys: Replace uid/gid/perm permissions checking with an ACL
2019-07-08Merge tag 'selinux-pr-20190702' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "Like the audit pull request this is a little early due to some upcoming vacation plans and uncertain network access while I'm away. Also like the audit PR, the list of patches here is pretty minor, the highlights include: - Explicitly use __le variables to make sure "sparse" can verify proper byte endian handling. - Remove some BUG_ON()s that are no longer needed. - Allow zero-byte writes to the "keycreate" procfs attribute without requiring key:create to make it easier for userspace to reset the keycreate label. - Consistently log the "invalid_context" field as an untrusted string in the AUDIT_SELINUX_ERR audit records" * tag 'selinux-pr-20190702' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: format all invalid context as untrusted selinux: fix empty write to keycreate file selinux: remove some no-op BUG_ONs selinux: provide __le variables explicitly
2019-06-27keys: Replace uid/gid/perm permissions checking with an ACLDavid Howells
Replace the uid/gid/perm permissions checking on a key with an ACL to allow the SETATTR and SEARCH permissions to be split. This will also allow a greater range of subjects to represented. ============ WHY DO THIS? ============ The problem is that SETATTR and SEARCH cover a slew of actions, not all of which should be grouped together. For SETATTR, this includes actions that are about controlling access to a key: (1) Changing a key's ownership. (2) Changing a key's security information. (3) Setting a keyring's restriction. And actions that are about managing a key's lifetime: (4) Setting an expiry time. (5) Revoking a key. and (proposed) managing a key as part of a cache: (6) Invalidating a key. Managing a key's lifetime doesn't really have anything to do with controlling access to that key. Expiry time is awkward since it's more about the lifetime of the content and so, in some ways goes better with WRITE permission. It can, however, be set unconditionally by a process with an appropriate authorisation token for instantiating a key, and can also be set by the key type driver when a key is instantiated, so lumping it with the access-controlling actions is probably okay. As for SEARCH permission, that currently covers: (1) Finding keys in a keyring tree during a search. (2) Permitting keyrings to be joined. (3) Invalidation. But these don't really belong together either, since these actions really need to be controlled separately. Finally, there are number of special cases to do with granting the administrator special rights to invalidate or clear keys that I would like to handle with the ACL rather than key flags and special checks. =============== WHAT IS CHANGED =============== The SETATTR permission is split to create two new permissions: (1) SET_SECURITY - which allows the key's owner, group and ACL to be changed and a restriction to be placed on a keyring. (2) REVOKE - which allows a key to be revoked. The SEARCH permission is split to create: (1) SEARCH - which allows a keyring to be search and a key to be found. (2) JOIN - which allows a keyring to be joined as a session keyring. (3) INVAL - which allows a key to be invalidated. The WRITE permission is also split to create: (1) WRITE - which allows a key's content to be altered and links to be added, removed and replaced in a keyring. (2) CLEAR - which allows a keyring to be cleared completely. This is split out to make it possible to give just this to an administrator. (3) REVOKE - see above. Keys acquire ACLs which consist of a series of ACEs, and all that apply are unioned together. An ACE specifies a subject, such as: (*) Possessor - permitted to anyone who 'possesses' a key (*) Owner - permitted to the key owner (*) Group - permitted to the key group (*) Everyone - permitted to everyone Note that 'Other' has been replaced with 'Everyone' on the assumption that you wouldn't grant a permit to 'Other' that you wouldn't also grant to everyone else. Further subjects may be made available by later patches. The ACE also specifies a permissions mask. The set of permissions is now: VIEW Can view the key metadata READ Can read the key content WRITE Can update/modify the key content SEARCH Can find the key by searching/requesting LINK Can make a link to the key SET_SECURITY Can change owner, ACL, expiry INVAL Can invalidate REVOKE Can revoke JOIN Can join this keyring CLEAR Can clear this keyring The KEYCTL_SETPERM function is then deprecated. The KEYCTL_SET_TIMEOUT function then is permitted if SET_SECURITY is set, or if the caller has a valid instantiation auth token. The KEYCTL_INVALIDATE function then requires INVAL. The KEYCTL_REVOKE function then requires REVOKE. The KEYCTL_JOIN_SESSION_KEYRING function then requires JOIN to join an existing keyring. The JOIN permission is enabled by default for session keyrings and manually created keyrings only. ====================== BACKWARD COMPATIBILITY ====================== To maintain backward compatibility, KEYCTL_SETPERM will translate the permissions mask it is given into a new ACL for a key - unless KEYCTL_SET_ACL has been called on that key, in which case an error will be returned. It will convert possessor, owner, group and other permissions into separate ACEs, if each portion of the mask is non-zero. SETATTR permission turns on all of INVAL, REVOKE and SET_SECURITY. WRITE permission turns on WRITE, REVOKE and, if a keyring, CLEAR. JOIN is turned on if a keyring is being altered. The KEYCTL_DESCRIBE function translates the ACL back into a permissions mask to return depending on possessor, owner, group and everyone ACEs. It will make the following mappings: (1) INVAL, JOIN -> SEARCH (2) SET_SECURITY -> SETATTR (3) REVOKE -> WRITE if SETATTR isn't already set (4) CLEAR -> WRITE Note that the value subsequently returned by KEYCTL_DESCRIBE may not match the value set with KEYCTL_SETATTR. ======= TESTING ======= This passes the keyutils testsuite for all but a couple of tests: (1) tests/keyctl/dh_compute/badargs: The first wrong-key-type test now returns EOPNOTSUPP rather than ENOKEY as READ permission isn't removed if the type doesn't have ->read(). You still can't actually read the key. (2) tests/keyctl/permitting/valid: The view-other-permissions test doesn't work as Other has been replaced with Everyone in the ACL. Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-14LSM: switch to blocking policy update notifiersJanne Karhunen
Atomic policy updaters are not very useful as they cannot usually perform the policy updates on their own. Since it seems that there is no strict need for the atomicity, switch to the blocking variant. While doing so, rename the functions accordingly. Signed-off-by: Janne Karhunen <janne.karhunen@gmail.com> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-06-12selinux: fix empty write to keycreate fileOndrej Mosnacek
When sid == 0 (we are resetting keycreate_sid to the default value), we should skip the KEY__CREATE check. Before this patch, doing a zero-sized write to /proc/self/keycreate would check if the current task can create unlabeled keys (which would usually fail with -EACCESS and generate an AVC). Now it skips the check and correctly sets the task's keycreate_sid to 0. Bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1719067 Tested using the reproducer from the report above. Fixes: 4eb582cf1fbd ("[PATCH] keys: add a way to store the appropriate context for newly-created keys") Reported-by: Kir Kolyshkin <kir@sacred.ru> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-06-12selinux: fix a missing-check bug in selinux_sb_eat_lsm_opts()Gen Zhang
In selinux_sb_eat_lsm_opts(), 'arg' is allocated by kmemdup_nul(). It returns NULL when fails. So 'arg' should be checked. And 'mnt_opts' should be freed when error. Signed-off-by: Gen Zhang <blackgod016574@gmail.com> Fixes: 99dbbb593fe6 ("selinux: rewrite selinux_sb_eat_lsm_opts()") Cc: <stable@vger.kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-06-12selinux: fix a missing-check bug in selinux_add_mnt_opt( )Gen Zhang
In selinux_add_mnt_opt(), 'val' is allocated by kmemdup_nul(). It returns NULL when fails. So 'val' should be checked. And 'mnt_opts' should be freed when error. Signed-off-by: Gen Zhang <blackgod016574@gmail.com> Fixes: 757cbe597fe8 ("LSM: new method: ->sb_add_mnt_opt()") Cc: <stable@vger.kernel.org> [PM: fixed some indenting problems] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-05-20selinux: do not report error on connect(AF_UNSPEC)Paolo Abeni
calling connect(AF_UNSPEC) on an already connected TCP socket is an established way to disconnect() such socket. After commit 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure") it no longer works and, in the above scenario connect() fails with EAFNOSUPPORT. Fix the above explicitly early checking for AF_UNSPEC family, and returning success in that case. Reported-by: Tom Deseyn <tdeseyn@redhat.com> Cc: stable@vger.kernel.org Fixes: 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure") Suggested-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-05-10Revert "selinux: do not report error on connect(AF_UNSPEC)"Paolo Abeni
This reverts commit c7e0d6cca86581092cbbf2cd868b3601495554cf. It was agreed a slightly different fix via the selinux tree. v1 -> v2: - use the correct reverted commit hash Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-08selinux: do not report error on connect(AF_UNSPEC)Paolo Abeni
calling connect(AF_UNSPEC) on an already connected TCP socket is an established way to disconnect() such socket. After commit 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure") it no longer works and, in the above scenario connect() fails with EAFNOSUPPORT. Fix the above falling back to the generic/old code when the address family is not AF_INET{4,6}, but leave the SCTP code path untouched, as it has specific constraints. Fixes: 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure") Reported-by: Tom Deseyn <tdeseyn@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-15selinux: Check address length before reading address familyTetsuo Handa
KMSAN will complain if valid address length passed to bind()/connect() is shorter than sizeof("struct sockaddr"->sa_family) bytes. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-04-04kernfs: fix xattr name handling in LSM helpersOndrej Mosnacek
The implementation of kernfs_security_xattr_*() helpers reuses the kernfs_node_xattr_*() functions, which take the suffix of the xattr name and extract full xattr name from it using xattr_full_name(). However, this function relies on the fact that the suffix passed to xattr handlers from VFS is always constructed from the full name by just incerementing the pointer. This doesn't necessarily hold for the callers of kernfs_security_xattr_*(), so their usage will easily lead to out-of-bounds access. Fix this by moving the xattr name reconstruction to the VFS xattr handlers and replacing the kernfs_security_xattr_*() helpers with more general kernfs_xattr_*() helpers that take full xattr name and allow accessing all kernfs node's xattrs. Reported-by: kernel test robot <rong.a.chen@intel.com> Fixes: b230d5aba2d1 ("LSM: add new hook for kernfs node initialization") Fixes: ec882da5cda9 ("selinux: implement the kernfs_init_security hook") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-22selinux: Make selinux_kernfs_init_security staticYueHaibing
Fix sparse warning: security/selinux/hooks.c:3389:5: warning: symbol 'selinux_kernfs_init_security' was not declared. Should it be static? Signed-off-by: YueHaibing <yuehaibing@huawei.com> Acked-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20selinux: implement the kernfs_init_security hookOndrej Mosnacek
The hook applies the same logic as selinux_determine_inode_label(), with the exception of the super_block handling, which will be enforced on the actual inodes later by other hooks. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> [PM: minor merge fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20selinux: try security xattr after genfs for kernfs filesystemsOndrej Mosnacek
Since kernfs supports the security xattr handlers, we can simply use these to determine the inode's context, dropping the need to update it from kernfs explicitly using a security_inode_notifysecctx() call. We achieve this by setting a new sbsec flag SE_SBGENFS_XATTR to all mounts that are known to use kernfs under the hood and then fetching the xattrs after determining the fallback genfs sid in inode_doinit_with_dentry() when this flag is set. This will allow implementing full security xattr support in kernfs and removing the ...notifysecctx() call in a subsequent patch. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> [PM: more manual merge fixups] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-13Merge tag 'selinux-pr-20190312' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux fixes from Paul Moore: "Two small fixes for SELinux in v5.1: one adds a buffer length check to the SELinux SCTP code, the other ensures that the SELinux labeling for a NFS mount is not disabled if the filesystem is mounted twice" * tag 'selinux-pr-20190312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock selinux: add the missing walk_size + len check in selinux_sctp_bind_connect
2019-03-12Merge branch 'work.mount' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs mount infrastructure updates from Al Viro: "The rest of core infrastructure; no new syscalls in that pile, but the old parts are switched to new infrastructure. At that point conversions of individual filesystems can happen independently; some are done here (afs, cgroup, procfs, etc.), there's also a large series outside of that pile dealing with NFS (quite a bit of option-parsing stuff is getting used there - it's one of the most convoluted filesystems in terms of mount-related logics), but NFS bits are the next cycle fodder. It got seriously simplified since the last cycle; documentation is probably the weakest bit at the moment - I considered dropping the commit introducing Documentation/filesystems/mount_api.txt (cutting the size increase by quarter ;-), but decided that it would be better to fix it up after -rc1 instead. That pile allows to do followup work in independent branches, which should make life much easier for the next cycle. fs/super.c size increase is unpleasant; there's a followup series that allows to shrink it considerably, but I decided to leave that until the next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits) afs: Use fs_context to pass parameters over automount afs: Add fs_context support vfs: Add some logging to the core users of the fs_context log vfs: Implement logging through fs_context vfs: Provide documentation for new mount API vfs: Remove kern_mount_data() hugetlbfs: Convert to fs_context cpuset: Use fs_context kernfs, sysfs, cgroup, intel_rdt: Support fs_context cgroup: store a reference to cgroup_ns into cgroup_fs_context cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper cgroup_do_mount(): massage calling conventions cgroup: stash cgroup_root reference into cgroup_fs_context cgroup2: switch to option-by-option parsing cgroup1: switch to option-by-option parsing cgroup: take options parsing into ->parse_monolithic() cgroup: fold cgroup1_mount() into cgroup1_get_tree() cgroup: start switching to fs_context ipc: Convert mqueue fs to fs_context proc: Add fs_context support to procfs ...
2019-03-11security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblockJ. Bruce Fields
In the case when we're reusing a superblock, selinux_sb_clone_mnt_opts() fails to set set_kern_flags, with the result that nfs_clone_sb_security() incorrectly clears NFS_CAP_SECURITY_LABEL. The result is that if you mount the same NFS filesystem twice, NFS security labels are turned off, even if they would work fine if you mounted the filesystem only once. ("fixes" may be not exactly the right tag, it may be more like "fixed-other-cases-but-missed-this-one".) Cc: Scott Mayhew <smayhew@redhat.com> Cc: stable@vger.kernel.org Fixes: 0b4d3452b8b4 "security/selinux: allow security_sb_clone_mnt_opts..." Signed-off-by: J. Bruce Fields <bfields@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-11selinux: add the missing walk_size + len check in selinux_sctp_bind_connectXin Long
As does in __sctp_connect(), when checking addrs in a while loop, after get the addr len according to sa_family, it's necessary to do the check walk_size + af->sockaddr_len > addrs_size to make sure it won't access an out-of-bounds addr. The same thing is needed in selinux_sctp_bind_connect(), otherwise an out-of-bounds issue can be triggered: [14548.772313] BUG: KASAN: slab-out-of-bounds in selinux_sctp_bind_connect+0x1aa/0x1f0 [14548.927083] Call Trace: [14548.938072] dump_stack+0x9a/0xe9 [14548.953015] print_address_description+0x65/0x22e [14548.996524] kasan_report.cold.6+0x92/0x1a6 [14549.015335] selinux_sctp_bind_connect+0x1aa/0x1f0 [14549.036947] security_sctp_bind_connect+0x58/0x90 [14549.058142] __sctp_setsockopt_connectx+0x5a/0x150 [sctp] [14549.081650] sctp_setsockopt.part.24+0x1322/0x3ce0 [sctp] Cc: stable@vger.kernel.org Fixes: d452930fd3b9 ("selinux: Add SCTP support") Reported-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-09Merge tag 'docs-5.1' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "A fairly routine cycle for docs - lots of typo fixes, some new documents, and more translations. There's also some LICENSES adjustments from Thomas" * tag 'docs-5.1' of git://git.lwn.net/linux: (74 commits) docs: Bring some order to filesystem documentation Documentation/locking/lockdep: Drop last two chars of sample states doc: rcu: Suspicious RCU usage is a warning docs: driver-api: iio: fix errors in documentation Documentation/process/howto: Update for 4.x -> 5.x versioning docs: Explicitly state that the 'Fixes:' tag shouldn't split lines doc: security: Add kern-doc for lsm_hooks.h doc: sctp: Merge and clean up rst files Docs: Correct /proc/stat path scripts/spdxcheck.py: fix C++ comment style detection doc: fix typos in license-rules.rst Documentation: fix admin-guide/README.rst minimum gcc version requirement doc: process: complete removal of info about -git patches doc: translations: sync translations 'remove info about -git patches' perf-security: wrap paragraphs on 72 columns perf-security: elaborate on perf_events/Perf privileged users perf-security: document collected perf_events/Perf data categories perf-security: document perf_events/Perf resource control sysfs.txt: add note on available attribute macros docs: kernel-doc: typo "if ... if" -> "if ... is" ...
2019-03-07Merge tag 'selinux-pr-20190305' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull SELinux updates from Paul Moore: "Nine SELinux patches for v5.1, all bug fixes. As far as I'm concerned, nothing really jumps out as risky or special to me, but each commit has a decent description so you can judge for yourself. As usual, everything passes the selinux-testsuite; please merge for v5.1" * tag 'selinux-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: fix avc audit messages selinux: replace BUG_ONs with WARN_ONs in avc.c selinux: log invalid contexts in AVCs selinux: replace some BUG_ON()s with a WARN_ON() selinux: inline some AVC functions used only once selinux: do not override context on context mounts selinux: never allow relabeling on context mounts selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_link selinux: avoid silent denials in permissive mode under RCU walk
2019-02-28introduce cloning of fs_contextAl Viro
new primitive: vfs_dup_fs_context(). Comes with fs_context method (->dup()) for copying the filesystem-specific parts of fs_context, along with LSM one (->fs_context_dup()) for doing the same to LSM parts. [needs better commit message, and change of Author:, anyway] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28selinux: Implement the new mount API LSM hooksDavid Howells
Implement the new mount API LSM hooks for SELinux. At some point the old hooks will need to be removed. Signed-off-by: David Howells <dhowells@redhat.com> cc: Paul Moore <paul@paul-moore.com> cc: Stephen Smalley <sds@tycho.nsa.gov> cc: selinux@tycho.nsa.gov cc: linux-security-module@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-22doc: sctp: Merge and clean up rst filesKees Cook
The SCTP sections were ending up at the top-level table of contents under the security section when they should have be sections with the SCTP chapters. In addition to correcting the section and subsection headings, this merges the SCTP documents into a single file to organize the chapters more clearly, internally linkifies them, and adds the missing SPDX header. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-01-18LSM: Make lsm_early_cred() and lsm_early_task() local functions.Tetsuo Handa
Since current->cred == current->real_cred when ordered_lsm_init() is called, and lsm_early_cred()/lsm_early_task() need to be called between the amount of required bytes is determined and module specific initialization function is called, we can move these calls from individual modules to ordered_lsm_init(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-01-10selinux: do not override context on context mountsOndrej Mosnacek
Ignore all selinux_inode_notifysecctx() calls on mounts with SBLABEL_MNT flag unset. This is achived by returning -EOPNOTSUPP for this case in selinux_inode_setsecurtity() (because that function should not be called in such case anyway) and translating this error to 0 in selinux_inode_notifysecctx(). This fixes behavior of kernfs-based filesystems when mounted with the 'context=' option. Before this patch, if a node's context had been explicitly set to a non-default value and later the filesystem has been remounted with the 'context=' option, then this node would show up as having the manually-set context and not the mount-specified one. Steps to reproduce: # mount -t cgroup2 cgroup2 /sys/fs/cgroup/unified # chcon unconfined_u:object_r:user_home_t:s0 /sys/fs/cgroup/unified/cgroup.stat # ls -lZ /sys/fs/cgroup/unified total 0 -r--r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Dec 13 10:41 cgroup.controllers -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Dec 13 10:41 cgroup.max.depth -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Dec 13 10:41 cgroup.max.descendants -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Dec 13 10:41 cgroup.procs -r--r--r--. 1 root root unconfined_u:object_r:user_home_t:s0 0 Dec 13 10:41 cgroup.stat -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Dec 13 10:41 cgroup.subtree_control -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Dec 13 10:41 cgroup.threads # umount /sys/fs/cgroup/unified # mount -o context=system_u:object_r:tmpfs_t:s0 -t cgroup2 cgroup2 /sys/fs/cgroup/unified Result before: # ls -lZ /sys/fs/cgroup/unified total 0 -r--r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.controllers -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.max.depth -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.max.descendants -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.procs -r--r--r--. 1 root root unconfined_u:object_r:user_home_t:s0 0 Dec 13 10:41 cgroup.stat -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.subtree_control -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.threads Result after: # ls -lZ /sys/fs/cgroup/unified total 0 -r--r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.controllers -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.max.depth -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.max.descendants -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.procs -r--r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.stat -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.subtree_control -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.threads Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-10selinux: never allow relabeling on context mountsOndrej Mosnacek
In the SECURITY_FS_USE_MNTPOINT case we never want to allow relabeling files/directories, so we should never set the SBLABEL_MNT flag. The 'special handling' in selinux_is_sblabel_mnt() is only intended for when the behavior is set to SECURITY_FS_USE_GENFS. While there, make the logic in selinux_is_sblabel_mnt() more explicit and add a BUILD_BUG_ON() to make sure that introducing a new SECURITY_FS_USE_* forces a review of the logic. Fixes: d5f3a5f6e7e7 ("selinux: add security in-core xattr support for pstore and debugfs") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-10selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_linkStephen Smalley
commit bda0be7ad9948 ("security: make inode_follow_link RCU-walk aware") switched selinux_inode_follow_link() to use avc_has_perm_flags() and pass down the MAY_NOT_BLOCK flag if called during RCU walk. However, the only test of MAY_NOT_BLOCK occurs during slow_avc_audit() and only if passing an inode as audit data (LSM_AUDIT_DATA_INODE). Since selinux_inode_follow_link() passes a dentry directly, passing MAY_NOT_BLOCK here serves no purpose. Switch selinux_inode_follow_link() to use avc_has_perm() and drop avc_has_perm_flags() since there are no other users. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-10selinux: avoid silent denials in permissive mode under RCU walkStephen Smalley
commit 0dc1ba24f7fff6 ("SELINUX: Make selinux cache VFS RCU walks safe") results in no audit messages at all if in permissive mode because the cache is updated during the rcu walk and thus no denial occurs on the subsequent ref walk. Fix this by not updating the cache when performing a non-blocking permission check. This only affects search and symlink read checks during rcu walk. Fixes: 0dc1ba24f7fff6 ("SELINUX: Make selinux cache VFS RCU walks safe") Reported-by: BMK <bmktuwien@gmail.com> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-10LSM: generalize flag passing to security_capableMicah Morton
This patch provides a general mechanism for passing flags to the security_capable LSM hook. It replaces the specific 'audit' flag that is used to tell security_capable whether it should log an audit message for the given capability check. The reason for generalizing this flag passing is so we can add an additional flag that signifies whether security_capable is being called by a setid syscall (which is needed by the proposed SafeSetID LSM). Signed-off-by: Micah Morton <mortonm@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-01-08LSM: Infrastructure management of the ipc security blobCasey Schaufler
Move management of the kern_ipc_perm->security and msg_msg->security blobs out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08SELinux: Abstract use of ipc security blobsCasey Schaufler
Don't use the ipc->security pointer directly. Don't use the msg_msg->security pointer directly. Provide helper functions that provides the security blob pointers. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08LSM: Infrastructure management of the inode securityCasey Schaufler
Move management of the inode->i_security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>