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2018-07-12->file_open(): lose cred argumentAl Viro1-1/+1
Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-04security: add hook for socketpair()David Herrmann1-0/+7
Right now the LSM labels for socketpairs are always uninitialized, since there is no security hook for the socketpair() syscall. This patch adds the required hooks so LSMs can properly label socketpairs. This allows SO_PEERSEC to return useful information on those sockets. Note that the behavior of socketpair() can be emulated by creating a listener socket, connecting to it, and then discarding the initial listener socket. With this workaround, SO_PEERSEC would return the caller's security context. However, with socketpair(), the uninitialized context is returned unconditionally. This is unexpected and makes socketpair() less useful in situations where the security context is crucial to the application. With the new socketpair-hook this disparity can be solved by making socketpair() return the expected security context. Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Tom Gundersen <teg@jklm.no> Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-04-07Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-securityLinus Torvalds1-0/+6
Pull integrity updates from James Morris: "A mixture of bug fixes, code cleanup, and continues to close IMA-measurement, IMA-appraisal, and IMA-audit gaps. Also note the addition of a new cred_getsecid LSM hook by Matthew Garrett: For IMA purposes, we want to be able to obtain the prepared secid in the bprm structure before the credentials are committed. Add a cred_getsecid hook that makes this possible. which is used by a new CREDS_CHECK target in IMA: In ima_bprm_check(), check with both the existing process credentials and the credentials that will be committed when the new process is started. This will not change behaviour unless the system policy is extended to include CREDS_CHECK targets - BPRM_CHECK will continue to check the same credentials that it did previously" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: ima: Fallback to the builtin hash algorithm ima: Add smackfs to the default appraise/measure list evm: check for remount ro in progress before writing ima: Improvements in ima_appraise_measurement() ima: Simplify ima_eventsig_init() integrity: Remove unused macro IMA_ACTION_RULE_FLAGS ima: drop vla in ima_audit_measurement() ima: Fix Kconfig to select TPM 2.0 CRB interface evm: Constify *integrity_status_msg[] evm: Move evm_hmac and evm_hash from evm_main.c to evm_crypto.c fuse: define the filesystem as untrusted ima: fail signature verification based on policy ima: clear IMA_HASH ima: re-evaluate files on privileged mounted filesystems ima: fail file signature verification on non-init mounted filesystems IMA: Support using new creds in appraisal policy security: Add a cred_getsecid hook
2018-04-07Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-securityLinus Torvalds1-219/+220
Pull general security layer updates from James Morris: - Convert security hooks from list to hlist, a nice cleanup, saving about 50% of space, from Sargun Dhillon. - Only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill (as the secid can be determined from the cred), from Stephen Smalley. - Close a potential race in kernel_read_file(), by making the file unwritable before calling the LSM check (vs after), from Kees Cook. * 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: security: convert security hooks to use hlist exec: Set file unwritable before LSM check usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill
2018-04-06Merge tag 'selinux-pr-20180403' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds1-0/+36
Pull SELinux updates from Paul Moore: "A bigger than usual pull request for SELinux, 13 patches (lucky!) along with a scary looking diffstat. Although if you look a bit closer, excluding the usual minor tweaks/fixes, there are really only two significant changes in this pull request: the addition of proper SELinux access controls for SCTP and the encapsulation of a lot of internal SELinux state. The SCTP changes are the result of a multi-month effort (maybe even a year or longer?) between the SELinux folks and the SCTP folks to add proper SELinux controls. A special thanks go to Richard for seeing this through and keeping the effort moving forward. The state encapsulation work is a bit of janitorial work that came out of some early work on SELinux namespacing. The question of namespacing is still an open one, but I believe there is some real value in the encapsulation work so we've split that out and are now sending that up to you" * tag 'selinux-pr-20180403' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: wrap AVC state selinux: wrap selinuxfs state selinux: fix handling of uninitialized selinux state in get_bools/classes selinux: Update SELinux SCTP documentation selinux: Fix ltp test connect-syscall failure selinux: rename the {is,set}_enforcing() functions selinux: wrap global selinux state selinux: fix typo in selinux_netlbl_sctp_sk_clone declaration selinux: Add SCTP support sctp: Add LSM hooks sctp: Add ip option support security: Add support for SCTP security hooks netlabel: If PF_INET6, check sk_buff ip header version
2018-03-31security: convert security hooks to use hlistSargun Dhillon1-214/+214
This changes security_hook_heads to use hlist_heads instead of the circular doubly-linked list heads. This should cut down the size of the struct by about half. In addition, it allows mutation of the hooks at the tail of the callback list without having to modify the head. The longer-term purpose of this is to enable making the heads read only. Signed-off-by: Sargun Dhillon <sargun@sargun.me> Reviewed-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>
2018-03-23security: Add a cred_getsecid hookMatthew Garrett1-0/+6
For IMA purposes, we want to be able to obtain the prepared secid in the bprm structure before the credentials are committed. Add a cred_getsecid hook that makes this possible. Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-03-22msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue security hooksEric W. Biederman1-6/+6
All of the implementations of security hooks that take msg_queue only access q_perm the struct kern_ipc_perm member. This means the dependencies of the msg_queue security hooks can be simplified by passing the kern_ipc_perm member of msg_queue. Making this change will allow struct msg_queue to become private to ipc/msg.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-22shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooksEric W. Biederman1-5/+5
All of the implementations of security hooks that take shmid_kernel only access shm_perm the struct kern_ipc_perm member. This means the dependencies of the shm security hooks can be simplified by passing the kern_ipc_perm member of shmid_kernel.. Making this change will allow struct shmid_kernel to become private to ipc/shm.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-22sem/security: Pass kern_ipc_perm not sem_array into the sem security hooksEric W. Biederman1-5/+5
All of the implementations of security hooks that take sem_array only access sem_perm the struct kern_ipc_perm member. This means the dependencies of the sem security hooks can be simplified by passing the kern_ipc_perm member of sem_array. Making this change will allow struct sem and struct sem_array to become private to ipc/sem.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-03-07usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_killStephen Smalley1-2/+3
commit d178bc3a708f39cbfefc3fab37032d3f2511b4ec ("user namespace: usb: make usb urbs user namespace aware (v2)") changed kill_pid_info_as_uid to kill_pid_info_as_cred, saving and passing a cred structure instead of uids. Since the secid can be obtained from the cred, drop the secid fields from the usb_dev_state and async structures, and drop the secid argument to kill_pid_info_as_cred. Replace the secid argument to security_task_kill with the cred. Update SELinux, Smack, and AppArmor to use the cred, which avoids the need for Smack and AppArmor to use a secid at all in this hook. Further changes to Smack might still be required to take full advantage of this change, since it should now be possible to perform capability checking based on the supplied cred. The changes to Smack and AppArmor have only been compile-tested. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2018-02-22security: Add support for SCTP security hooksRichard Haines1-0/+36
The SCTP security hooks are explained in: Documentation/security/LSM-sctp.rst Signed-off-by: Richard Haines <richard_c_haines@btinternet.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-10-20security: bpf: Add LSM hooks for bpf object related syscallChenbo Feng1-0/+54
Introduce several LSM hooks for the syscalls that will allow the userspace to access to eBPF object such as eBPF programs and eBPF maps. The security check is aimed to enforce a per object security protection for eBPF object so only processes with the right priviliges can read/write to a specific map or use a specific eBPF program. Besides that, a general security hook is added before the multiplexer of bpf syscall to check the cmd and the attribute used for the command. The actual security module can decide which command need to be checked and how the cmd should be checked. Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-12Merge tag 'selinux-pr-20170831' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds1-7/+0
Pull selinux updates from Paul Moore: "A relatively quiet period for SELinux, 11 patches with only two/three having any substantive changes. These noteworthy changes include another tweak to the NNP/nosuid handling, per-file labeling for cgroups, and an object class fix for AF_UNIX/SOCK_RAW sockets; the rest of the changes are minor tweaks or administrative updates (Stephen's email update explains the file explosion in the diffstat). Everything passes the selinux-testsuite" [ Also a couple of small patches from the security tree from Tetsuo Handa for Tomoyo and LSM cleanup. The separation of security policy updates wasn't all that clean - Linus ] * tag 'selinux-pr-20170831' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: constify nf_hook_ops selinux: allow per-file labeling for cgroupfs lsm_audit: update my email address selinux: update my email address MAINTAINERS: update the NetLabel and Labeled Networking information selinux: use GFP_NOWAIT in the AVC kmem_caches selinux: Generalize support for NNP/nosuid SELinux domain transitions selinux: genheaders should fail if too many permissions are defined selinux: update the selinux info in MAINTAINERS credits: update Paul Moore's info selinux: Assign proper class to PF_UNIX/SOCK_RAW sockets tomoyo: Update URLs in Documentation/admin-guide/LSM/tomoyo.rst LSM: Remove security_task_create() hook.
2017-08-01LSM: drop bprm_secureexec hookKees Cook1-9/+5
This removes the bprm_secureexec hook since the logic has been folded into the bprm_set_creds hook for all LSMs now. Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: John Johansen <john.johansen@canonical.com> Acked-by: James Morris <james.l.morris@oracle.com> Acked-by: Serge Hallyn <serge@hallyn.com>
2017-07-25sync to Linus v4.13-rc2 for subsystem developers to work againstJames Morris1-15/+14
2017-07-19Merge tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linuxLinus Torvalds1-2/+2
Pull structure randomization updates from Kees Cook: "Now that IPC and other changes have landed, enable manual markings for randstruct plugin, including the task_struct. This is the rest of what was staged in -next for the gcc-plugins, and comes in three patches, largest first: - mark "easy" structs with __randomize_layout - mark task_struct with an optional anonymous struct to isolate the __randomize_layout section - mark structs to opt _out_ of automated marking (which will come later) And, FWIW, this continues to pass allmodconfig (normal and patched to enable gcc-plugins) builds of x86_64, i386, arm64, arm, powerpc, and s390 for me" * tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: randstruct: opt-out externally exposed function pointer structs task_struct: Allow randomized layout randstruct: Mark various structs for randomization
2017-07-18LSM: Remove security_task_create() hook.Tetsuo Handa1-7/+0
Since commit a79be238600d1a03 ("selinux: Use task_alloc hook rather than task_create hook") changed to use task_alloc hook, task_create hook is no longer used. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-07-05Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-securityLinus Torvalds1-1/+38
Pull security layer updates from James Morris: - a major update for AppArmor. From JJ: * several bug fixes and cleanups * the patch to add symlink support to securityfs that was floated on the list earlier and the apparmorfs changes that make use of securityfs symlinks * it introduces the domain labeling base code that Ubuntu has been carrying for several years, with several cleanups applied. And it converts the current mediation over to using the domain labeling base, which brings domain stacking support with it. This finally will bring the base upstream code in line with Ubuntu and provide a base to upstream the new feature work that Ubuntu carries. * This does _not_ contain any of the newer apparmor mediation features/controls (mount, signals, network, keys, ...) that Ubuntu is currently carrying, all of which will be RFC'd on top of this. - Notable also is the Infiniband work in SELinux, and the new file:map permission. From Paul: "While we're down to 21 patches for v4.13 (it was 31 for v4.12), the diffstat jumps up tremendously with over 2k of line changes. Almost all of these changes are the SELinux/IB work done by Daniel Jurgens; some other noteworthy changes include a NFS v4.2 labeling fix, a new file:map permission, and reporting of policy capabilities on policy load" There's also now genfscon labeling support for tracefs, which was lost in v4.1 with the separation from debugfs. - Smack incorporates a safer socket check in file_receive, and adds a cap_capable call in privilege check. - TPM as usual has a bunch of fixes and enhancements. - Multiple calls to security_add_hooks() can now be made for the same LSM, to allow LSMs to have hook declarations across multiple files. - IMA now supports different "ima_appraise=" modes (eg. log, fix) from the boot command line. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (126 commits) apparmor: put back designators in struct initialisers seccomp: Switch from atomic_t to recount_t seccomp: Adjust selftests to avoid double-join seccomp: Clean up core dump logic IMA: update IMA policy documentation to include pcr= option ima: Log the same audit cause whenever a file has no signature ima: Simplify policy_func_show. integrity: Small code improvements ima: fix get_binary_runtime_size() ima: use ima_parse_buf() to parse template data ima: use ima_parse_buf() to parse measurements headers ima: introduce ima_parse_buf() ima: Add cgroups2 to the defaults list ima: use memdup_user_nul ima: fix up #endif comments IMA: Correct Kconfig dependencies for hash selection ima: define is_ima_appraise_enabled() ima: define Kconfig IMA_APPRAISE_BOOTPARAM option ima: define a set of appraisal rules requiring file signatures ima: extend the "ima_policy" boot command line to support multiple policies ...
2017-06-30randstruct: Mark various structs for randomizationKees Cook1-2/+2
This marks many critical kernel structures for randomization. These are structures that have been targeted in the past in security exploits, or contain functions pointers, pointers to function pointer tables, lists, workqueues, ref-counters, credentials, permissions, or are otherwise sensitive. This initial list was extracted from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Left out of this list is task_struct, which requires special handling and will be covered in a subsequent patch. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-06-09security/selinux: allow security_sb_clone_mnt_opts to enable/disable native labeling behaviorScott Mayhew1-1/+3
When an NFSv4 client performs a mount operation, it first mounts the NFSv4 root and then does path walk to the exported path and performs a submount on that, cloning the security mount options from the root's superblock to the submount's superblock in the process. Unless the NFS server has an explicit fsid=0 export with the "security_label" option, the NFSv4 root superblock will not have SBLABEL_MNT set, and neither will the submount superblock after cloning the security mount options. As a result, setxattr's of security labels over NFSv4.2 will fail. In a similar fashion, NFSv4.2 mounts mounted with the context= mount option will not show the correct labels because the nfs_server->caps flags of the cloned superblock will still have NFS_CAP_SECURITY_LABEL set. Allowing the NFSv4 client to enable or disable SECURITY_LSM_NATIVE_LABELS behavior will ensure that the SBLABEL_MNT flag has the correct value when the client traverses from an exported path without the "security_label" option to one with the "security_label" option and vice versa. Similarly, checking to see if SECURITY_LSM_NATIVE_LABELS is set upon return from security_sb_clone_mnt_opts() and clearing NFS_CAP_SECURITY_LABEL if necessary will allow the correct labels to be displayed for NFSv4.2 mounts mounted with the context= mount option. Resolves: https://github.com/SELinuxProject/selinux-kernel/issues/35 Signed-off-by: Scott Mayhew <smayhew@redhat.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> Tested-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23IB/core: Enforce security on management datagramsDaniel Jurgens1-0/+8
Allocate and free a security context when creating and destroying a MAD agent. This context is used for controlling access to PKeys and sending and receiving SMPs. When sending or receiving a MAD check that the agent has permission to access the PKey for the Subnet Prefix of the port. During MAD and snoop agent registration for SMI QPs check that the calling process has permission to access the manage the subnet and register a callback with the LSM to be notified of policy changes. When notificaiton of a policy change occurs recheck permission and set a flag indicating sending and receiving SMPs is allowed. When sending and receiving MADs check that the agent has access to the SMI if it's on an SMI QP. Because security policy can change it's possible permission was allowed when creating the agent, but no longer is. Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Acked-by: Doug Ledford <dledford@redhat.com> [PM: remove the LSM hook init code] Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23IB/core: Enforce PKey security on QPsDaniel Jurgens1-0/+27
Add new LSM hooks to allocate and free security contexts and check for permission to access a PKey. Allocate and free a security context when creating and destroying a QP. This context is used for controlling access to PKeys. When a request is made to modify a QP that changes the port, PKey index, or alternate path, check that the QP has permission for the PKey in the PKey table index on the subnet prefix of the port. If the QP is shared make sure all handles to the QP also have access. Store which port and PKey index a QP is using. After the reset to init transition the user can modify the port, PKey index and alternate path independently. So port and PKey settings changes can be a merge of the previous settings and the new ones. In order to maintain access control if there are PKey table or subnet prefix change keep a list of all QPs are using each PKey index on each port. If a change occurs all QPs using that device and port must have access enforced for the new cache settings. These changes add a transaction to the QP modify process. Association with the old port and PKey index must be maintained if the modify fails, and must be removed if it succeeds. Association with the new port and PKey index must be established prior to the modify and removed if the modify fails. 1. When a QP is modified to a particular Port, PKey index or alternate path insert that QP into the appropriate lists. 2. Check permission to access the new settings. 3. If step 2 grants access attempt to modify the QP. 4a. If steps 2 and 3 succeed remove any prior associations. 4b. If ether fails remove the new setting associations. If a PKey table or subnet prefix changes walk the list of QPs and check that they have permission. If not send the QP to the error state and raise a fatal error event. If it's a shared QP make sure all the QPs that share the real_qp have permission as well. If the QP that owns a security structure is denied access the security structure is marked as such and the QP is added to an error_list. Once the moving the QP to error is complete the security structure mark is cleared. Maintaining the lists correctly turns QP destroy into a transaction. The hardware driver for the device frees the ib_qp structure, so while the destroy is in progress the ib_qp pointer in the ib_qp_security struct is undefined. When the destroy process begins the ib_qp_security structure is marked as destroying. This prevents any action from being taken on the QP pointer. After the QP is destroyed successfully it could still listed on an error_list wait for it to be processed by that flow before cleaning up the structure. If the destroy fails the QPs port and PKey settings are reinserted into the appropriate lists, the destroying flag is cleared, and access control is enforced, in case there were any cache changes during the destroy flow. To keep the security changes isolated a new file is used to hold security related functionality. Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Acked-by: Doug Ledford <dledford@redhat.com> [PM: merge fixup in ib_verbs.h and uverbs_cmd.c] Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-18doc: security: minor cleanups to build kernel-docKees Cook1-13/+12
These fixes were needed to parse lsm_hooks.h kernel-doc. More work is needed, but this is the first step. Acked-by: James Morris <james.l.morris@oracle.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-03-28LSM: Revive security_task_alloc() hook and per "struct task_struct" security blob.Tetsuo Handa1-1/+8
We switched from "struct task_struct"->security to "struct cred"->security in Linux 2.6.29. But not all LSM modules were happy with that change. TOMOYO LSM module is an example which want to use per "struct task_struct" security blob, for TOMOYO's security context is defined based on "struct task_struct" rather than "struct cred". AppArmor LSM module is another example which want to use it, for AppArmor is currently abusing the cred a little bit to store the change_hat and setexeccon info. Although security_task_free() hook was revived in Linux 3.4 because Yama LSM module wanted to release per "struct task_struct" security blob, security_task_alloc() hook and "struct task_struct"->security field were not revived. Nowadays, we are getting proposals of lightweight LSM modules which want to use per "struct task_struct" security blob. We are already allowing multiple concurrent LSM modules (up to one fully armored module which uses "struct cred"->security field or exclusive hooks like security_xfrm_state_pol_flow_match(), plus unlimited number of lightweight modules which do not use "struct cred"->security nor exclusive hooks) as long as they are built into the kernel. But this patch does not implement variable length "struct task_struct"->security field which will become needed when multiple LSM modules want to use "struct task_struct"-> security field. Although it won't be difficult to implement variable length "struct task_struct"->security field, let's think about it after we merged this patch. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Tested-by: Djalal Harouni <tixxdz@gmail.com> Acked-by: José Bollo <jobol@nonadev.net> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@parisplace.org> Cc: Kees Cook <keescook@chromium.org> Cc: James Morris <james.l.morris@oracle.com> Cc: José Bollo <jobol@nonadev.net> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-03-06security: introduce CONFIG_SECURITY_WRITABLE_HOOKSJames Morris1-0/+7
Subsequent patches will add RO hardening to LSM hooks, however, SELinux still needs to be able to perform runtime disablement after init to handle architectures where init-time disablement via boot parameters is not feasible. Introduce a new kernel configuration parameter CONFIG_SECURITY_WRITABLE_HOOKS, and a helper macro __lsm_ro_after_init, to handle this case. Signed-off-by: James Morris <james.l.morris@oracle.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Kees Cook <keescook@chromium.org>
2017-03-06prlimit,security,selinux: add a security hook for prlimitStephen Smalley1-3/+15
When SELinux was first added to the kernel, a process could only get and set its own resource limits via getrlimit(2) and setrlimit(2), so no MAC checks were required for those operations, and thus no security hooks were defined for them. Later, SELinux introduced a hook for setlimit(2) with a check if the hard limit was being changed in order to be able to rely on the hard limit value as a safe reset point upon context transitions. Later on, when prlimit(2) was added to the kernel with the ability to get or set resource limits (hard or soft) of another process, LSM/SELinux was not updated other than to pass the target process to the setrlimit hook. This resulted in incomplete control over both getting and setting the resource limits of another process. Add a new security_task_prlimit() hook to the check_prlimit_permission() function to provide complete mediation. The hook is only called when acting on another task, and only if the existing DAC/capability checks would allow access. Pass flags down to the hook to indicate whether the prlimit(2) call will read, write, or both read and write the resource limits of the target process. The existing security_task_setrlimit() hook is left alone; it continues to serve a purpose in supporting the ability to make decisions based on the old and/or new resource limit values when setting limits. This is consistent with the DAC/capability logic, where check_prlimit_permission() performs generic DAC/capability checks for acting on another task, while do_prlimit() performs a capability check based on a comparison of the old and new resource limits. Fix the inline documentation for the hook to match the code. Implement the new hook for SELinux. For setting resource limits, we reuse the existing setrlimit permission. Note that this does overload the setrlimit permission to mean the ability to set the resource limit (soft or hard) of another process or the ability to change one's own hard limit. For getting resource limits, a new getrlimit permission is defined. This was not originally defined since getrlimit(2) could only be used to obtain a process' own limits. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-02-10Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/selinux into nextJames Morris1-9/+1
2017-01-19LSM: Add /sys/kernel/security/lsmCasey Schaufler1-8/+4
I am still tired of having to find indirect ways to determine what security modules are active on a system. I have added /sys/kernel/security/lsm, which contains a comma separated list of the active security modules. No more groping around in /proc/filesystems or other clever hacks. Unchanged from previous versions except for being updated to the latest security next branch. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-01-12security,selinux,smack: kill security_task_wait hookStephen Smalley1-7/+0
As reported by yangshukui, a permission denial from security_task_wait() can lead to a soft lockup in zap_pid_ns_processes() since it only expects sys_wait4() to return 0 or -ECHILD. Further, security_task_wait() can in general lead to zombies; in the absence of some way to automatically reparent a child process upon a denial, the hook is not useful. Remove the security hook and its implementations in SELinux and Smack. Smack already removed its check from its hook. Reported-by: yangshukui <yangshukui@huawei.com> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-01-10security: Fix inode_getattr documentationMickaël Salaün1-2/+1
Replace arguments @mnt and @dentry with @path. Signed-off-by: Mickaël Salaün <mic@digikod.net> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-01-09proc,security: move restriction on writing /proc/pid/attr nodes to procStephen Smalley1-2/+1
Processes can only alter their own security attributes via /proc/pid/attr nodes. This is presently enforced by each individual security module and is also imposed by the Linux credentials implementation, which only allows a task to alter its own credentials. Move the check enforcing this restriction from the individual security modules to proc_pid_attr_write() before calling the security hook, and drop the unnecessary task argument to the security hook since it can only ever be the current task. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-09-19Merge branch 'stable-4.9' of git://git.infradead.org/users/pcmoore/selinux into nextJames Morris1-0/+36
2016-08-09module: Fully remove the kernel_module_from_file hookMickaël Salaün1-1/+0
Remove remaining kernel_module_from_file hook left by commit a1db74209483 ("module: replace copy_module_from_fd with kernel version") Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-08-08security, overlayfs: Provide hook to correctly label newly created filesVivek Goyal1-0/+15
During a new file creation we need to make sure new file is created with the right label. New file is created in upper/ so effectively file should get label as if task had created file in upper/. We switched to mounter's creds for actual file creation. Also if there is a whiteout present, then file will be created in work/ dir first and then renamed in upper. In none of the cases file will be labeled as we want it to be. This patch introduces a new hook dentry_create_files_as(), which determines the label/context dentry will get if it had been created by task in upper and modify passed set of creds appropriately. Caller makes use of these new creds for file creation. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: fix whitespace issues found with checkpatch.pl] [PM: changes to use stat->mode in ovl_create_or_link()] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-08-08security,overlayfs: Provide security hook for copy up of xattrs for overlay fileVivek Goyal1-0/+10
Provide a security hook which is called when xattrs of a file are being copied up. This hook is called once for each xattr and LSM can return 0 if the security module wants the xattr to be copied up, 1 if the security module wants the xattr to be discarded on the copy, -EOPNOTSUPP if the security module does not handle/manage the xattr, or a -errno upon an error. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: whitespace cleanup for checkpatch.pl] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-08-08security, overlayfs: provide copy up security hook for unioned filesVivek Goyal1-0/+11
Provide a security hook to label new file correctly when a file is copied up from lower layer to upper layer of a overlay/union mount. This hook can prepare a new set of creds which are suitable for new file creation during copy up. Caller will use new creds to create file and then revert back to old creds and release new creds. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: whitespace cleanup to appease checkpatch.pl] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-07-20qstr: constify dentry_init_securityAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-19Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-securityLinus Torvalds1-1/+5
Pull security subsystem updates from James Morris: "Highlights: - A new LSM, "LoadPin", from Kees Cook is added, which allows forcing of modules and firmware to be loaded from a specific device (this is from ChromeOS, where the device as a whole is verified cryptographically via dm-verity). This is disabled by default but can be configured to be enabled by default (don't do this if you don't know what you're doing). - Keys: allow authentication data to be stored in an asymmetric key. Lots of general fixes and updates. - SELinux: add restrictions for loading of kernel modules via finit_module(). Distinguish non-init user namespace capability checks. Apply execstack check on thread stacks" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (48 commits) LSM: LoadPin: provide enablement CONFIG Yama: use atomic allocations when reporting seccomp: Fix comment typo ima: add support for creating files using the mknodat syscall ima: fix ima_inode_post_setattr vfs: forbid write access when reading a file into memory fs: fix over-zealous use of "const" selinux: apply execstack check on thread stacks selinux: distinguish non-init user namespace capability checks LSM: LoadPin for kernel file loading restrictions fs: define a string representation of the kernel_read_file_id enumeration Yama: consolidate error reporting string_helpers: add kstrdup_quotable_file string_helpers: add kstrdup_quotable_cmdline string_helpers: add kstrdup_quotable selinux: check ss_initialized before revalidating an inode label selinux: delay inode label lookup as long as possible selinux: don't revalidate an inode's label when explicitly setting it selinux: Change bool variable name to index. KEYS: Add KEYCTL_DH_COMPUTE command ...
2016-05-17Merge branch 'work.const-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-14/+14
Pull 'struct path' constification update from Al Viro: "'struct path' is passed by reference to a bunch of Linux security methods; in theory, there's nothing to stop them from modifying the damn thing and LSM community being what it is, sooner or later some enterprising soul is going to decide that it's a good idea. Let's remove the temptation and constify all of those..." * 'work.const-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: constify ima_d_path() constify security_sb_pivotroot() constify security_path_chroot() constify security_path_{link,rename} apparmor: remove useless checks for NULL ->mnt constify security_path_{mkdir,mknod,symlink} constify security_path_{unlink,rmdir} apparmor: constify common_perm_...() apparmor: constify aa_path_link() apparmor: new helper - common_path_perm() constify chmod_common/security_path_chmod constify security_sb_mount() constify chown_common/security_path_chown tomoyo: constify assorted struct path * apparmor_path_truncate(): path->mnt is never NULL constify vfs_truncate() constify security_path_truncate() [apparmor] constify struct path * in a bunch of helpers
2016-04-22security: Introduce security_settime64()Baolin Wang1-2/+3
security_settime() uses a timespec, which is not year 2038 safe on 32bit systems. Thus this patch introduces the security_settime64() function with timespec64 type. We also convert the cap_settime() helper function to use the 64bit types. This patch then moves security_settime() to the header file as an inline helper function so that existing users can be iteratively converted. None of the existing hooks is using the timespec argument and therefor the patch is not making any functional changes. Cc: Serge Hallyn <serge.hallyn@canonical.com>, Cc: James Morris <james.l.morris@oracle.com>, Cc: "Serge E. Hallyn" <serge@hallyn.com>, Cc: Paul Moore <pmoore@redhat.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Kees Cook <keescook@chromium.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> [jstultz: Reworded commit message] Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-04-21LSM: LoadPin for kernel file loading restrictionsKees Cook1-0/+5
This LSM enforces that kernel-loaded files (modules, firmware, etc) must all come from the same filesystem, with the expectation that such a filesystem is backed by a read-only device such as dm-verity or CDROM. This allows systems that have a verified and/or unchangeable filesystem to enforce module and firmware loading restrictions without needing to sign the files individually. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-04-11security: drop the unused hook skb_owned_byPaolo Abeni1-1/+0
The skb_owned_by hook was added with the commit ca10b9e9a8ca ("selinux: add a skb_owned_by() hook") and later removed when said commit was reverted. Later on, when switching to list of hooks, a field named 'skb_owned_by' was included into the security_hook_head struct, but without any users nor caller. This commit removes the said left-over field. Fixes: b1d9e6b0646d ("LSM: Switch to lists of hooks") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Paul Moore <pmoore@paul-moore.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-03-28constify security_sb_pivotroot()Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28constify security_path_chroot()Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28constify security_path_{link,rename}Al Viro1-3/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28constify security_path_{mkdir,mknod,symlink}Al Viro1-3/+3
... as well as unix_mknod() and may_o_create() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28constify security_path_{unlink,rmdir}Al Viro1-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28constify chmod_common/security_path_chmodAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28constify security_sb_mount()Al Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>