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* Merge tag 'lsm-pr-20241112' of ↵Linus Torvalds2024-11-191-2/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm Pull lsm updates from Paul Moore: "Thirteen patches, all focused on moving away from the current 'secid' LSM identifier to a richer 'lsm_prop' structure. This move will help reduce the translation that is necessary in many LSMs, offering better performance, and make it easier to support different LSMs in the future" * tag 'lsm-pr-20241112' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: lsm: remove lsm_prop scaffolding netlabel,smack: use lsm_prop for audit data audit: change context data from secid to lsm_prop lsm: create new security_cred_getlsmprop LSM hook audit: use an lsm_prop in audit_names lsm: use lsm_prop in security_inode_getsecid lsm: use lsm_prop in security_current_getsecid audit: update shutdown LSM data lsm: use lsm_prop in security_ipc_getsecid audit: maintain an lsm_prop in audit_context lsm: add lsmprop_to_secctx hook lsm: use lsm_prop in security_audit_rule_match lsm: add the lsm_prop data structure
| * lsm: add lsmprop_to_secctx hookCasey Schaufler2024-10-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | Add a new hook security_lsmprop_to_secctx() and its LSM specific implementations. The LSM specific code will use the lsm_prop element allocated for that module. This allows for the possibility that more than one module may be called upon to translate a secid to a string, as can occur in the audit code. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> [PM: subject line tweak] Signed-off-by: Paul Moore <paul@paul-moore.com>
| * lsm: use lsm_prop in security_audit_rule_matchCasey Schaufler2024-10-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the secid parameter of security_audit_rule_match to a lsm_prop structure pointer. Pass the entry from the lsm_prop structure for the approprite slot to the LSM hook. Change the users of security_audit_rule_match to use the lsm_prop instead of a u32. The scaffolding function lsmprop_init() fills the structure with the value of the old secid, ensuring that it is available to the appropriate module hook. The sources of the secid, security_task_getsecid() and security_inode_getsecid(), will be converted to use the lsm_prop structure later in the series. At that point the use of lsmprop_init() is dropped. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> [PM: subject line tweak] Signed-off-by: Paul Moore <paul@paul-moore.com>
* | selinux: Add netlink xperm supportThiébaud Weksteen2024-10-074-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reuse the existing extended permissions infrastructure to support policies based on the netlink message types. A new policy capability "netlink_xperm" is introduced. When disabled, the previous behaviour is preserved. That is, netlink_send will rely on the permission mappings defined in nlmsgtab.c (e.g, nlmsg_read for RTM_GETADDR on NETLINK_ROUTE). When enabled, the mappings are ignored and the generic "nlmsg" permission is used instead. The new "nlmsg" permission is an extended permission. The 16 bits of the extended permission are mapped to the nlmsg_type field. Example policy on Android, preventing regular apps from accessing the device's MAC address and ARP table, but allowing this access to privileged apps, looks as follows: allow netdomain self:netlink_route_socket { create read getattr write setattr lock append connect getopt setopt shutdown nlmsg }; allowxperm netdomain self:netlink_route_socket nlmsg ~{ RTM_GETLINK RTM_GETNEIGH RTM_GETNEIGHTBL }; allowxperm priv_app self:netlink_route_socket nlmsg { RTM_GETLINK RTM_GETNEIGH RTM_GETNEIGHTBL }; The constants in the example above (e.g., RTM_GETLINK) are explicitly defined in the policy. It is possible to generate policies to support kernels that may or may not have the capability enabled by generating a rule for each scenario. For instance: allow domain self:netlink_audit_socket nlmsg_read; allow domain self:netlink_audit_socket nlmsg; allowxperm domain self:netlink_audit_socket nlmsg { AUDIT_GET }; The approach of defining a new permission ("nlmsg") instead of relying on the existing permissions (e.g., "nlmsg_read", "nlmsg_readpriv" or "nlmsg_tty_audit") has been preferred because: 1. This is similar to the other extended permission ("ioctl"); 2. With the new extended permission, the coarse-grained mapping is not necessary anymore. It could eventually be removed, which would be impossible if the extended permission was defined below these. 3. Having a single extra extended permission considerably simplifies the implementation here and in libselinux. Signed-off-by: Thiébaud Weksteen <tweek@google.com> Signed-off-by: Bram Bonné <brambonne@google.com> [PM: manual merge fixes for sock_skip_has_perm()] Signed-off-by: Paul Moore <paul@paul-moore.com>
* | selinux: do not include <linux/*.h> headers from host programsMasahiro Yamada2024-10-032-3/+12
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | The header, security/selinux/include/classmap.h, is included not only from kernel space but also from host programs. It includes <linux/capability.h> and <linux/socket.h>, which pull in more <linux/*.h> headers. This makes the host programs less portable, specifically causing build errors on macOS. Those headers are included for the following purposes: - <linux/capability.h> for checking CAP_LAST_CAP - <linux/socket.h> for checking PF_MAX These checks can be guarded by __KERNEL__ so they are skipped when building host programs. Testing them when building the kernel should be sufficient. The header, security/selinux/include/initial_sid_to_string.h, includes <linux/stddef.h> for the NULL definition, but this is not portable either. Instead, <stddef.h> should be included for host programs. Reported-by: Daniel Gomez <da.gomez@samsung.com> Closes: https://lore.kernel.org/lkml/20240807-macos-build-support-v1-6-4cd1ded85694@samsung.com/ Closes: https://lore.kernel.org/lkml/20240807-macos-build-support-v1-7-4cd1ded85694@samsung.com/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
* Merge tag 'lsm-pr-20240911' of ↵Linus Torvalds2024-09-161-0/+28
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm Pull lsm updates from Paul Moore: - Move the LSM framework to static calls This transitions the vast majority of the LSM callbacks into static calls. Those callbacks which haven't been converted were left as-is due to the general ugliness of the changes required to support the static call conversion; we can revisit those callbacks at a future date. - Add the Integrity Policy Enforcement (IPE) LSM This adds a new LSM, Integrity Policy Enforcement (IPE). There is plenty of documentation about IPE in this patches, so I'll refrain from going into too much detail here, but the basic motivation behind IPE is to provide a mechanism such that administrators can restrict execution to only those binaries which come from integrity protected storage, e.g. a dm-verity protected filesystem. You will notice that IPE requires additional LSM hooks in the initramfs, dm-verity, and fs-verity code, with the associated patches carrying ACK/review tags from the associated maintainers. We couldn't find an obvious maintainer for the initramfs code, but the IPE patchset has been widely posted over several years. Both Deven Bowers and Fan Wu have contributed to IPE's development over the past several years, with Fan Wu agreeing to serve as the IPE maintainer moving forward. Once IPE is accepted into your tree, I'll start working with Fan to ensure he has the necessary accounts, keys, etc. so that he can start submitting IPE pull requests to you directly during the next merge window. - Move the lifecycle management of the LSM blobs to the LSM framework Management of the LSM blobs (the LSM state buffers attached to various kernel structs, typically via a void pointer named "security" or similar) has been mixed, some blobs were allocated/managed by individual LSMs, others were managed by the LSM framework itself. Starting with this pull we move management of all the LSM blobs, minus the XFRM blob, into the framework itself, improving consistency across LSMs, and reducing the amount of duplicated code across LSMs. Due to some additional work required to migrate the XFRM blob, it has been left as a todo item for a later date; from a practical standpoint this omission should have little impact as only SELinux provides a XFRM LSM implementation. - Fix problems with the LSM's handling of F_SETOWN The LSM hook for the fcntl(F_SETOWN) operation had a couple of problems: it was racy with itself, and it was disconnected from the associated DAC related logic in such a way that the LSM state could be updated in cases where the DAC state would not. We fix both of these problems by moving the security_file_set_fowner() hook into the same section of code where the DAC attributes are updated. Not only does this resolve the DAC/LSM synchronization issue, but as that code block is protected by a lock, it also resolve the race condition. - Fix potential problems with the security_inode_free() LSM hook Due to use of RCU to protect inodes and the placement of the LSM hook associated with freeing the inode, there is a bit of a challenge when it comes to managing any LSM state associated with an inode. The VFS folks are not open to relocating the LSM hook so we have to get creative when it comes to releasing an inode's LSM state. Traditionally we have used a single LSM callback within the hook that is triggered when the inode is "marked for death", but not actually released due to RCU. Unfortunately, this causes problems for LSMs which want to take an action when the inode's associated LSM state is actually released; so we add an additional LSM callback, inode_free_security_rcu(), that is called when the inode's LSM state is released in the RCU free callback. - Refactor two LSM hooks to better fit the LSM return value patterns The vast majority of the LSM hooks follow the "return 0 on success, negative values on failure" pattern, however, there are a small handful that have unique return value behaviors which has caused confusion in the past and makes it difficult for the BPF verifier to properly vet BPF LSM programs. This includes patches to convert two of these"special" LSM hooks to the common 0/-ERRNO pattern. - Various cleanups and improvements A handful of patches to remove redundant code, better leverage the IS_ERR_OR_NULL() helper, add missing "static" markings, and do some minor style fixups. * tag 'lsm-pr-20240911' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (40 commits) security: Update file_set_fowner documentation fs: Fix file_set_fowner LSM hook inconsistencies lsm: Use IS_ERR_OR_NULL() helper function lsm: remove LSM_COUNT and LSM_CONFIG_COUNT ipe: Remove duplicated include in ipe.c lsm: replace indirect LSM hook calls with static calls lsm: count the LSMs enabled at compile time kernel: Add helper macros for loop unrolling init/main.c: Initialize early LSMs after arch code, static keys and calls. MAINTAINERS: add IPE entry with Fan Wu as maintainer documentation: add IPE documentation ipe: kunit test for parser scripts: add boot policy generation program ipe: enable support for fs-verity as a trust provider fsverity: expose verified fsverity built-in signatures to LSMs lsm: add security_inode_setintegrity() hook ipe: add support for dm-verity as a trust provider dm-verity: expose root hash digest and signature data to LSMs block,lsm: add LSM blob and new LSM hooks for block devices ipe: add permissive toggle ...
| * lsm: infrastructure management of the perf_event security blobCasey Schaufler2024-07-291-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Move management of the perf_event->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. There are no longer any modules that require the perf_event_free() hook. The hook definition has been removed. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com> [PM: subject tweak] Signed-off-by: Paul Moore <paul@paul-moore.com>
| * lsm: infrastructure management of the infiniband blobCasey Schaufler2024-07-291-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Move management of the infiniband security blob out of the individual security modules and into the LSM infrastructure. The security modules tell the infrastructure how much space they require at initialization. There are no longer any modules that require the ib_free() hook. The hook definition has been removed. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com> [PM: subject tweak, selinux style fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
| * lsm: infrastructure management of the dev_tun blobCasey Schaufler2024-07-291-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Move management of the dev_tun security blob out of the individual security modules and into the LSM infrastructure. The security modules tell the infrastructure how much space they require at initialization. There are no longer any modules that require the dev_tun_free hook. The hook definition has been removed. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com> [PM: subject tweak, selinux style fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
| * lsm: infrastructure management of the key security blobCasey Schaufler2024-07-291-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Move management of the key->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. There are no existing modules that require a key_free hook, so the call to it and the definition for it have been removed. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com> [PM: subject tweak] Signed-off-by: Paul Moore <paul@paul-moore.com>
| * lsm: infrastructure management of the sock securityCasey Schaufler2024-07-291-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move management of the sock->sk_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. Acked-by: Paul Moore <paul@paul-moore.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: John Johansen <john.johansen@canonical.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> [PM: subject tweak] Signed-off-by: Paul Moore <paul@paul-moore.com>
* | selinux: fix style problems in security/selinux/include/audit.hPaul Moore2024-09-041-23/+23
|/ | | | | | Remove the needless indent in the function comment header blocks. Signed-off-by: Paul Moore <paul@paul-moore.com>
* ima: Avoid blocking in RCU read-side critical sectionGUO Zihua2024-06-131-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A panic happens in ima_match_policy: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 42f873067 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 5 PID: 1286325 Comm: kubeletmonit.sh Kdump: loaded Tainted: P Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ima_match_policy+0x84/0x450 Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39 7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea 44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f RSP: 0018:ff71570009e07a80 EFLAGS: 00010207 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200 RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739 R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970 R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001 FS: 00007f5195b51740(0000) GS:ff3e278b12d40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ima_get_action+0x22/0x30 process_measurement+0xb0/0x830 ? page_add_file_rmap+0x15/0x170 ? alloc_set_pte+0x269/0x4c0 ? prep_new_page+0x81/0x140 ? simple_xattr_get+0x75/0xa0 ? selinux_file_open+0x9d/0xf0 ima_file_check+0x64/0x90 path_openat+0x571/0x1720 do_filp_open+0x9b/0x110 ? page_counter_try_charge+0x57/0xc0 ? files_cgroup_alloc_fd+0x38/0x60 ? __alloc_fd+0xd4/0x250 ? do_sys_open+0x1bd/0x250 do_sys_open+0x1bd/0x250 do_syscall_64+0x5d/0x1d0 entry_SYSCALL_64_after_hwframe+0x65/0xca Commit c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a RCU read-side critical section which contains kmalloc with GFP_KERNEL. This implies a possible sleep and violates limitations of RCU read-side critical sections on non-PREEMPT systems. Sleeping within RCU read-side critical section might cause synchronize_rcu() returning early and break RCU protection, allowing a UAF to happen. The root cause of this issue could be described as follows: | Thread A | Thread B | | |ima_match_policy | | | rcu_read_lock | |ima_lsm_update_rule | | | synchronize_rcu | | | | kmalloc(GFP_KERNEL)| | | sleep | ==> synchronize_rcu returns early | kfree(entry) | | | | entry = entry->next| ==> UAF happens and entry now becomes NULL (or could be anything). | | entry->action | ==> Accessing entry might cause panic. To fix this issue, we are converting all kmalloc that is called within RCU read-side critical section to use GFP_ATOMIC. Fixes: c7423dbdbc9e ("ima: Handle -ESTALE returned by ima_filter_rule_match()") Cc: stable@vger.kernel.org Signed-off-by: GUO Zihua <guozihua@huawei.com> Acked-by: John Johansen <john.johansen@canonical.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> [PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/initial_sid_to_string.hPaul Moore2023-12-231-29/+28
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/xfrm.hPaul Moore2023-12-231-2/+2
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/security.hPaul Moore2023-12-231-80/+75
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues with security/selinux/include/policycap_names.hPaul Moore2023-12-231-0/+3
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/policycap.hPaul Moore2023-12-231-0/+1
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/objsec.hPaul Moore2023-12-231-64/+65
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues with security/selinux/include/netlabel.hPaul Moore2023-12-231-33/+20
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/netif.hPaul Moore2023-12-231-2/+2
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/ima.hPaul Moore2023-12-231-1/+1
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/conditional.hPaul Moore2023-12-231-2/+2
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/classmap.hPaul Moore2023-12-231-210/+132
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/avc_ss.hPaul Moore2023-12-231-1/+1
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: align avc_has_perm_noaudit() prototype with definitionPaul Moore2023-12-231-1/+1
| | | | | | | | | | | A trivial correction to convert an 'unsigned' parameter into an 'unsigned int' parameter so the prototype matches the function definition. I really thought that someone submitted a patch for this a few years ago but sadly I can't find it now. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/avc.hPaul Moore2023-12-231-26/+15
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/include/audit.hPaul Moore2023-12-231-1/+0
| | | | | | | | | | | | As part of on ongoing effort to perform more automated testing and provide more tools for individual developers to validate their patches before submitting, we are trying to make our code "clang-format clean". My hope is that once we have fixed all of our style "quirks", developers will be able to run clang-format on their patches to help avoid silly formatting problems and ensure their changes fit in well with the rest of the SELinux kernel code. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: introduce an initial SID for early boot processesOndrej Mosnacek2023-11-224-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, SELinux doesn't allow distinguishing between kernel threads and userspace processes that are started before the policy is first loaded - both get the label corresponding to the kernel SID. The only way a process that persists from early boot can get a meaningful label is by doing a voluntary dyntransition or re-executing itself. Reusing the kernel label for userspace processes is problematic for several reasons: 1. The kernel is considered to be a privileged domain and generally needs to have a wide range of permissions allowed to work correctly, which prevents the policy writer from effectively hardening against early boot processes that might remain running unintentionally after the policy is loaded (they represent a potential extra attack surface that should be mitigated). 2. Despite the kernel being treated as a privileged domain, the policy writer may want to impose certain special limitations on kernel threads that may conflict with the requirements of intentional early boot processes. For example, it is a good hardening practice to limit what executables the kernel can execute as usermode helpers and to confine the resulting usermode helper processes. However, a (legitimate) process surviving from early boot may need to execute a different set of executables. 3. As currently implemented, overlayfs remembers the security context of the process that created an overlayfs mount and uses it to bound subsequent operations on files using this context. If an overlayfs mount is created before the SELinux policy is loaded, these "mounter" checks are made against the kernel context, which may clash with restrictions on the kernel domain (see 2.). To resolve this, introduce a new initial SID (reusing the slot of the former "init" initial SID) that will be assigned to any userspace process started before the policy is first loaded. This is easy to do, as we can simply label any process that goes through the bprm_creds_for_exec LSM hook with the new init-SID instead of propagating the kernel SID from the parent. To provide backwards compatibility for existing policies that are unaware of this new semantic of the "init" initial SID, introduce a new policy capability "userspace_initial_context" and set the "init" SID to the same context as the "kernel" SID unless this capability is set by the policy. Another small backwards compatibility measure is needed in security_sid_to_context_core() for before the initial SELinux policy load - see the code comment for explanation. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> [PM: edited comments based on feedback/discussion] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: revert SECINITSID_INIT supportPaul Moore2023-08-094-9/+1
| | | | | | | | | | | | | | | This commit reverts 5b0eea835d4e ("selinux: introduce an initial SID for early boot processes") as it was found to cause problems on distros with old SELinux userspace tools/libraries, specifically Ubuntu 16.04. Hopefully we will be able to re-add this functionality at a later date, but let's revert this for now to help ensure a stable and backwards compatible SELinux tree. Link: https://lore.kernel.org/selinux/87edkseqf8.fsf@mail.lhotse Acked-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: avoid implicit conversions in services codeChristian Göttsche2023-08-041-2/+2
| | | | | | | | | | | | | | | | | | Use u32 as the output parameter type in security_get_classes() and security_get_permissions(), based on the type of the symtab nprim member. Declare the read-only class string parameter of security_get_permissions() const. Avoid several implicit conversions by using the identical type for the destination. Use the type identical to the source for local variables. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: cleanup extra whitespace in subject] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: update my email addressStephen Smalley2023-07-194-4/+4
| | | | | | | Update my email address; MAINTAINERS was updated some time ago. Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: de-brand SELinuxStephen Smalley2023-07-191-1/+1
| | | | | | | | | | | | | | Change "NSA SELinux" to just "SELinux" in Kconfig help text and comments. While NSA was the original primary developer and continues to help maintain SELinux, SELinux has long since transitioned to a wide community of developers and maintainers. SELinux has been part of the mainline Linux kernel for nearly 20 years now [1] and has received contributions from many individuals and organizations. [1] https://lore.kernel.org/lkml/Pine.LNX.4.44.0308082228470.1852-100000@home.osdl.org/ Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: avoid implicit conversions regarding enforcing statusChristian Göttsche2023-07-191-1/+1
| | | | | | | | | | | Use the type bool as parameter type in selinux_status_update_setenforce(). The related function enforcing_enabled() returns the type bool, while the struct selinux_kernel_status member enforcing uses an u32. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: subject line tweaks] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: consistently use u32 as sequence number type in the status codeChristian Göttsche2023-07-191-1/+1
| | | | | | | | | Align the type with the one used in selinux_notify_policy_change() and the sequence member of struct selinux_kernel_status. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: subject line tweaks] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: introduce an initial SID for early boot processesOndrej Mosnacek2023-07-104-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, SELinux doesn't allow distinguishing between kernel threads and userspace processes that are started before the policy is first loaded - both get the label corresponding to the kernel SID. The only way a process that persists from early boot can get a meaningful label is by doing a voluntary dyntransition or re-executing itself. Reusing the kernel label for userspace processes is problematic for several reasons: 1. The kernel is considered to be a privileged domain and generally needs to have a wide range of permissions allowed to work correctly, which prevents the policy writer from effectively hardening against early boot processes that might remain running unintentionally after the policy is loaded (they represent a potential extra attack surface that should be mitigated). 2. Despite the kernel being treated as a privileged domain, the policy writer may want to impose certain special limitations on kernel threads that may conflict with the requirements of intentional early boot processes. For example, it is a good hardening practice to limit what executables the kernel can execute as usermode helpers and to confine the resulting usermode helper processes. However, a (legitimate) process surviving from early boot may need to execute a different set of executables. 3. As currently implemented, overlayfs remembers the security context of the process that created an overlayfs mount and uses it to bound subsequent operations on files using this context. If an overlayfs mount is created before the SELinux policy is loaded, these "mounter" checks are made against the kernel context, which may clash with restrictions on the kernel domain (see 2.). To resolve this, introduce a new initial SID (reusing the slot of the former "init" initial SID) that will be assigned to any userspace process started before the policy is first loaded. This is easy to do, as we can simply label any process that goes through the bprm_creds_for_exec LSM hook with the new init-SID instead of propagating the kernel SID from the parent. To provide backwards compatibility for existing policies that are unaware of this new semantic of the "init" initial SID, introduce a new policy capability "userspace_initial_context" and set the "init" SID to the same context as the "kernel" SID unless this capability is set by the policy. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: cleanup the policycap accessor functionsPaul Moore2023-07-101-24/+11
| | | | | | | | | In the process of reverting back to directly accessing the global selinux_state pointer we left behind some artifacts in the selinux_policycap_XXX() helper functions. This patch cleans up some of that left-behind cruft. Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: make labeled NFS work when mounted before policy loadOndrej Mosnacek2023-05-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, when an NFS filesystem that supports passing LSM/SELinux labels is mounted during early boot (before the SELinux policy is loaded), it ends up mounted without the labeling support (i.e. with Fedora policy all files get the generic NFS label system_u:object_r:nfs_t:s0). This is because the information that the NFS mount supports passing labels (communicated to the LSM layer via the kern_flags argument of security_set_mnt_opts()) gets lost and when the policy is loaded the mount is initialized as if the passing is not supported. Fix this by noting the "native labeling" in newsbsec->flags (using a new SE_SBNATIVE flag) on the pre-policy-loaded call of selinux_set_mnt_opts() and then making sure it is respected on the second call from delayed_superblock_init(). Additionally, make inode_doinit_with_dentry() initialize the inode's label from its extended attributes whenever it doesn't find it already intitialized by the filesystem. This is needed to properly initialize pre-existing inodes when delayed_superblock_init() is called. It should not trigger in any other cases (and if it does, it's still better to initialize the correct label instead of leaving the inode unlabeled). Fixes: eb9ae686507b ("SELinux: Add new labeling type native labels") Tested-by: Scott Mayhew <smayhew@redhat.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> [PM: fixed 'Fixes' tag format] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: cleanup exit_sel_fs() declarationXiu Jianfeng2023-05-301-1/+0
| | | | | | | | exit_sel_fs() has been removed since commit f22f9aaf6c3d ("selinux: remove the runtime disable functionality"). Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: make header files self-includingChristian Göttsche2023-05-182-0/+4
| | | | | | | | | | | Include all necessary headers in header files to enable third party applications, like LSP servers, to resolve all used symbols. ibpkey.h: include "flask.h" for SECINITSID_UNLABELED initial_sid_to_string.h: include <linux/stddef.h> for NULL Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: avc: drop unused function avc_disable()Christian Göttsche2023-05-081-3/+0
| | | | | | | | Since commit f22f9aaf6c3d ("selinux: remove the runtime disable functionality") the function avc_disable() is no longer used. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: adjust typos in commentsChristian Göttsche2023-05-082-2/+2
| | | | | | | Found by codespell(1) Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: remove the runtime disable functionalityPaul Moore2023-03-201-21/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After working with the larger SELinux-based distros for several years, we're finally at a place where we can disable the SELinux runtime disable functionality. The existing kernel deprecation notice explains the functionality and why we want to remove it: The selinuxfs "disable" node allows SELinux to be disabled at runtime prior to a policy being loaded into the kernel. If disabled via this mechanism, SELinux will remain disabled until the system is rebooted. The preferred method of disabling SELinux is via the "selinux=0" boot parameter, but the selinuxfs "disable" node was created to make it easier for systems with primitive bootloaders that did not allow for easy modification of the kernel command line. Unfortunately, allowing for SELinux to be disabled at runtime makes it difficult to secure the kernel's LSM hooks using the "__ro_after_init" feature. It is that last sentence, mentioning the '__ro_after_init' hardening, which is the real motivation for this change, and if you look at the diffstat you'll see that the impact of this patch reaches across all the different LSMs, helping prevent tampering at the LSM hook level. From a SELinux perspective, it is important to note that if you continue to disable SELinux via "/etc/selinux/config" it may appear that SELinux is disabled, but it is simply in an uninitialized state. If you load a policy with `load_policy -i`, you will see SELinux come alive just as if you had loaded the policy during early-boot. It is also worth noting that the "/sys/fs/selinux/disable" file is always writable now, regardless of the Kconfig settings, but writing to the file has no effect on the system, other than to display an error on the console if a non-zero/true value is written. Finally, in the several years where we have been working on deprecating this functionality, there has only been one instance of someone mentioning any user visible breakage. In this particular case it was an individual's kernel test system, and the workaround documented in the deprecation notice ("selinux=0" on the kernel command line) resolved the issue without problem. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: remove the 'checkreqprot' functionalityPaul Moore2023-03-201-9/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We originally promised that the SELinux 'checkreqprot' functionality would be removed no sooner than June 2021, and now that it is March 2023 it seems like it is a good time to do the final removal. The deprecation notice in the kernel provides plenty of detail on why 'checkreqprot' is not desirable, with the key point repeated below: This was a compatibility mechanism for legacy userspace and for the READ_IMPLIES_EXEC personality flag. However, if set to 1, it weakens security by allowing mappings to be made executable without authorization by policy. The default value of checkreqprot at boot was changed starting in Linux v4.4 to 0 (i.e. check the actual protection), and Android and Linux distributions have been explicitly writing a "0" to /sys/fs/selinux/checkreqprot during initialization for some time. Along with the official deprecation notice, we have been discussing this on-list and directly with several of the larger SELinux-based distros and everyone is happy to see this feature finally removed. In an attempt to catch all of the smaller, and DIY, Linux systems we have been writing a deprecation notice URL into the kernel log, along with a growing ssleep() penalty, when admins enabled checkreqprot at runtime or via the kernel command line. We have yet to have anyone come to us and raise an objection to the deprecation or planned removal. It is worth noting that while this patch removes the checkreqprot functionality, it leaves the user visible interfaces (kernel command line and selinuxfs file) intact, just inert. This should help prevent breakages with existing userspace tools that correctly, but unnecessarily, disable checkreqprot at boot or runtime. Admins that attempt to enable checkreqprot will be met with a removal message in the kernel log. Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: stop passing selinux_state pointers and their offspringStephen Smalley2023-03-145-135/+82
| | | | | | | | | | | | | | | | | | | Linus observed that the pervasive passing of selinux_state pointers introduced by me in commit aa8e712cee93 ("selinux: wrap global selinux state") adds overhead and complexity without providing any benefit. The original idea was to pave the way for SELinux namespaces but those have not yet been implemented and there isn't currently a concrete plan to do so. Remove the passing of the selinux_state pointers, reverting to direct use of the single global selinux_state, and likewise remove passing of child pointers like the selinux_avc. The selinux_policy pointer remains as it is needed for atomic switching of policies. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202303101057.mZ3Gv5fK-lkp@intel.com/ Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* Merge tag 'lsm-pr-20221003' of ↵Linus Torvalds2022-10-041-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm Pull LSM updates from Paul Moore: "Seven patches for the LSM layer and we've got a mix of trivial and significant patches. Highlights below, starting with the smaller bits first so they don't get lost in the discussion of the larger items: - Remove some redundant NULL pointer checks in the common LSM audit code. - Ratelimit the lockdown LSM's access denial messages. With this change there is a chance that the last visible lockdown message on the console is outdated/old, but it does help preserve the initial series of lockdown denials that started the denial message flood and my gut feeling is that these might be the more valuable messages. - Open userfaultfds as readonly instead of read/write. While this code obviously lives outside the LSM, it does have a noticeable impact on the LSMs with Ondrej explaining the situation in the commit description. It is worth noting that this patch languished on the VFS list for over a year without any comments (objections or otherwise) so I took the liberty of pulling it into the LSM tree after giving fair notice. It has been in linux-next since the end of August without any noticeable problems. - Add a LSM hook for user namespace creation, with implementations for both the BPF LSM and SELinux. Even though the changes are fairly small, this is the bulk of the diffstat as we are also including BPF LSM selftests for the new hook. It's also the most contentious of the changes in this pull request with Eric Biederman NACK'ing the LSM hook multiple times during its development and discussion upstream. While I've never taken NACK's lightly, I'm sending these patches to you because it is my belief that they are of good quality, satisfy a long-standing need of users and distros, and are in keeping with the existing nature of the LSM layer and the Linux Kernel as a whole. The patches in implement a LSM hook for user namespace creation that allows for a granular approach, configurable at runtime, which enables both monitoring and control of user namespaces. The general consensus has been that this is far preferable to the other solutions that have been adopted downstream including outright removal from the kernel, disabling via system wide sysctls, or various other out-of-tree mechanisms that users have been forced to adopt since we haven't been able to provide them an upstream solution for their requests. Eric has been steadfast in his objections to this LSM hook, explaining that any restrictions on the user namespace could have significant impact on userspace. While there is the possibility of impacting userspace, it is important to note that this solution only impacts userspace when it is requested based on the runtime configuration supplied by the distro/admin/user. Frederick (the pathset author), the LSM/security community, and myself have tried to work with Eric during development of this patchset to find a mutually acceptable solution, but Eric's approach and unwillingness to engage in a meaningful way have made this impossible. I have CC'd Eric directly on this pull request so he has a chance to provide his side of the story; there have been no objections outside of Eric's" * tag 'lsm-pr-20221003' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: lockdown: ratelimit denial messages userfaultfd: open userfaultfds with O_RDONLY selinux: Implement userns_create hook selftests/bpf: Add tests verifying bpf lsm userns_create hook bpf-lsm: Make bpf_lsm_userns_create() sleepable security, lsm: Introduce security_create_user_ns() lsm: clean up redundant NULL pointer check
| * selinux: Implement userns_create hookFrederick Lawler2022-08-161-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unprivileged user namespace creation is an intended feature to enable sandboxing, however this feature is often used to as an initial step to perform a privilege escalation attack. This patch implements a new user_namespace { create } access control permission to restrict which domains allow or deny user namespace creation. This is necessary for system administrators to quickly protect their systems while waiting for vulnerability patches to be applied. This permission can be used in the following way: allow domA_t domA_t : user_namespace { create }; Signed-off-by: Frederick Lawler <fred@cloudflare.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* | selinux: implement the security_uring_cmd() LSM hookPaul Moore2022-08-261-1/+1
|/ | | | | | | | | | | | | | | | Add a SELinux access control for the iouring IORING_OP_URING_CMD command. This includes the addition of a new permission in the existing "io_uring" object class: "cmd". The subject of the new permission check is the domain of the process requesting access, the object is the open file which points to the device/file that is the target of the IORING_OP_URING_CMD operation. A sample policy rule is shown below: allow <domain> <file>:io_uring { cmd }; Cc: stable@vger.kernel.org Fixes: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd") Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix typos in commentsJonas Lindner2022-06-101-1/+1
| | | | | | Signed-off-by: Jonas Lindner <jolindner@gmx.de> [PM: fixed duplicated subject line] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: add __randomize_layout to selinux_audit_dataGONG, Ruiqi2022-06-071-1/+1
| | | | | | | | | | | Randomize the layout of struct selinux_audit_data as suggested in [1], since it contains a pointer to struct selinux_state, an already randomized strucure. [1]: https://github.com/KSPP/linux/issues/188 Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>