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* selinux: replace kmem_cache_create() with KMEM_CACHE()Eric Suen2024-08-273-11/+4
| | | | | | | | | | Based on guidance in include/linux/slab.h, replace kmem_cache_create() with KMEM_CACHE() for sources under security/selinux to simplify creation of SLAB caches. Signed-off-by: Eric Suen <ericsu@linux.microsoft.com> [PM: minor grammar nits in the description] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: Streamline type determination in security_compute_sidCanfeng Guo2024-07-291-17/+19
| | | | | | | | | | | Simplifies the logic for determining the security context type in security_compute_sid, enhancing readability and efficiency. Consolidates default type assignment logic next to type transition checks, removing redundancy and improving code flow. Signed-off-by: Canfeng Guo <guocanfeng@uniontech.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* Merge tag 'selinux-pr-20240715' of ↵Linus Torvalds2024-07-161-1/+1
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux update from Paul Moore: "A single SELinux patch to change the type of a pre-processor constant to better match its use" * tag 'selinux-pr-20240715' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: Use 1UL for EBITMAP_BIT to match maps type
| * selinux: Use 1UL for EBITMAP_BIT to match maps typeCanfeng Guo2024-07-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch modifies the definition of EBITMAP_BIT in security/selinux/ss/ebitmap.h from 1ULL to 1UL to match the type of elements in the ebitmap_node maps array. This change does not affect the functionality or correctness of the code but aims to enhance code quality by adhering to good programming practices and avoiding unnecessary type conversions. Signed-off-by: Canfeng Guo <guocanfeng@uniontech.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* | ima: Avoid blocking in RCU read-side critical sectionGUO Zihua2024-06-131-2/+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: constify source policy in cond_policydb_dup()Christian Göttsche2024-04-304-14/+17
| | | | | | | | | cond_policydb_dup() duplicates conditional parts of an existing policy. Declare the source policy const, since it should not be modified. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: various line length fixups] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: avoid printk_ratelimit()Christian Göttsche2024-04-301-2/+1
| | | | | | | | | | | | The usage of printk_ratelimit() is discouraged, see include/linux/printk.h, thus use pr_warn_ratelimited(). While editing this line address the following checkpatch warning: WARNING: Integer promotion: Using 'h' in '%hu' is unnecessary Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: clarify return code in filename_trans_read_helper_compat()Ondrej Mosnacek2024-04-041-0/+1
| | | | | | | | | | | | | | | | | | | | For the "conflicting/duplicate rules" branch in filename_trans_read_helper_compat() the Smatch static checker reports: security/selinux/ss/policydb.c:1953 filename_trans_read_helper_compat() warn: missing error code 'rc' While the value of rc will already always be zero here, it is not obvious that it's the case and that it's the intended return value (Smatch expects rc to be assigned within 5 lines from the goto). Therefore, add an explicit assignment just before the goto to make the intent more clear and the code less error-prone. Fixes: c3a276111ea2 ("selinux: optimize storage of filename transitions") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Link: https://lore.kernel.org/selinux/722b90c4-1f4b-42ff-a6c2-108ea262bd10@moroto.mountain/ Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: use u32 as bit position type in ebitmap codeChristian Göttsche2024-03-272-35/+34
| | | | | | | | | | | The extensible bitmap supports bit positions up to U32_MAX due to the type of the member highbit being u32. Use u32 consistently as the type for bit positions to announce to callers what range of values is supported. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: merge fuzz, subject line tweak] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: improve symtab string hashingChristian Göttsche2024-03-271-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The number of buckets is calculated by performing a binary AND against the mask of the hash table, which is one less than its size (which is a power of two). This leads to all top bits being discarded, requiring for short or similar inputs a hash function with a good avalanche effect. Use djb2a: # current common prefixes: 7 entries and 5/8 buckets used, longest chain length 2, sum of chain length^2 11 classes: 134 entries and 100/256 buckets used, longest chain length 5, sum of chain length^2 234 roles: 15 entries and 6/16 buckets used, longest chain length 5, sum of chain length^2 57 types: 4448 entries and 3016/8192 buckets used, longest chain length 41, sum of chain length^2 14922 users: 7 entries and 3/8 buckets used, longest chain length 3, sum of chain length^2 17 bools: 306 entries and 221/512 buckets used, longest chain length 4, sum of chain length^2 524 levels: 1 entries and 1/1 buckets used, longest chain length 1, sum of chain length^2 1 categories: 1024 entries and 400/1024 buckets used, longest chain length 4, sum of chain length^2 2740 # patch common prefixes: 7 entries and 5/8 buckets used, longest chain length 2, sum of chain length^2 11 classes: 134 entries and 101/256 buckets used, longest chain length 3, sum of chain length^2 210 roles: 15 entries and 9/16 buckets used, longest chain length 3, sum of chain length^2 31 types: 4448 entries and 3459/8192 buckets used, longest chain length 5, sum of chain length^2 6778 users: 7 entries and 5/8 buckets used, longest chain length 3, sum of chain length^2 13 bools: 306 entries and 236/512 buckets used, longest chain length 5, sum of chain length^2 470 levels: 1 entries and 1/1 buckets used, longest chain length 1, sum of chain length^2 1 categories: 1024 entries and 518/1024 buckets used, longest chain length 7, sum of chain length^2 2992 Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: line length fixes in the commit message] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: dump statistics for more hash tablesChristian Göttsche2024-03-272-7/+19
| | | | | | | | | | Dump in the SELinux debug configuration the statistics for the conditional rules avtab, the role transition, and class and common permission hash tables. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: style fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: update numeric format specifiers for ebitmapsChristian Göttsche2024-03-271-6/+6
| | | | | | | | | | | | | Use the correct, according to Documentation/core-api/printk-formats.rst, format specifiers for numeric arguments in string formatting. The general bit type is u32 thus use %u, EBITMAP_SIZE is a constant computed via sizeof() thus use %zu. Fixes: 0142c56682fb ("selinux: reject invalid ebitmaps") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/linux-next/20240327131044.2c629921@canb.auug.org.au/ Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: reject invalid ebitmapsChristian Göttsche2024-03-261-0/+11
| | | | | | | | | | | Reject ebitmaps with a node containing an empty map or with an incorrect highbit. Both checks are already performed by userspace, the former since 2008 (patch 13cd4c896068 ("initial import from svn trunk revision 2950")), the latter since v2.7 in 2017 (patch 75b14a5de10a ("libsepol: ebitmap: reject loading bitmaps with incorrect high bit")). Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: fix style issues in security/selinux/ss/symtab.cPaul Moore2024-02-231-1/+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/ss/symtab.hPaul Moore2024-02-231-5/+4
| | | | | | | | | | | | 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/ss/sidtab.cPaul Moore2024-02-231-32/+37
| | | | | | | | | | | | 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/ss/sidtab.hPaul Moore2024-02-231-17/+19
| | | | | | | | | | | | 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/ss/services.hPaul Moore2024-02-231-1/+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/ss/policydb.cPaul Moore2024-02-231-192/+213
| | | | | | | | | | | | 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/ss/policydb.hPaul Moore2024-02-231-97/+95
| | | | | | | | | | | | 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/ss/mls_types.hPaul Moore2024-02-231-16/+16
| | | | | | | | | | | | 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/ss/mls.cPaul Moore2024-02-231-50/+33
| | | | | | | | | | | | 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/ss/mls.hPaul Moore2024-02-231-39/+19
| | | | | | | | | | | | 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/ss/hashtab.cPaul Moore2024-02-231-12/+11
| | | | | | | | | | | | 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/ss/hashtab.hPaul Moore2024-02-231-18/+17
| | | | | | | | | | | | 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/ss/ebitmap.cPaul Moore2024-02-231-28/+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/ss/ebitmap.hPaul Moore2024-02-231-19/+23
| | | | | | | | | | | | 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/ss/context.hPaul Moore2024-02-231-1/+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/ss/context.hPaul Moore2024-02-231-19/+22
| | | | | | | | | | | | 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/ss/constraint.hPaul Moore2024-02-231-33/+34
| | | | | | | | | | | | 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/ss/conditional.cPaul Moore2024-02-231-35/+33
| | | | | | | | | | | | 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/ss/conditional.hPaul Moore2024-02-231-12/+11
| | | | | | | | | | | | 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/ss/avtab.cPaul Moore2024-02-231-54/+51
| | | | | | | | | | | | 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/ss/avtab.hPaul Moore2024-02-231-37/+37
| | | | | | | | | | | | 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 Mosnacek2023-11-212-1/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: refactor avtab_node comparisonsJacob Satterfield2023-11-201-60/+41
| | | | | | | | | | | | | | In four separate functions within avtab, the same comparison logic is used. The only difference is how the result is handled or whether there is a unique specifier value to be checked for or used. Extracting this functionality into the avtab_node_cmp() function unifies the comparison logic between searching and insertion and gets rid of duplicative code so that the implementation is easier to maintain. Signed-off-by: Jacob Satterfield <jsatterfield.linux@gmail.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: update filenametr_hash() to use full_name_hash()Paul Moore2023-11-161-9/+2
| | | | | | | | Using full_name_hash() instead of partial_name_hash() should result in cleaner and better performing code. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: simplify avtab_insert_node() prototypeJacob Satterfield2023-10-031-13/+7
| | | | | | | | | | __hashtab_insert() in hashtab.h has a cleaner interface that allows the caller to specify the chain node location that the new node is being inserted into so that it can update the node that currently occupies it. Signed-off-by: Jacob Satterfield <jsatterfield.linux@gmail.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: hweight optimization in avtab_read_itemJacob Satterfield2023-09-131-5/+2
| | | | | | | | | | | | | | | | | | | | | avtab_read_item() is a hot function called when reading each rule in a binary policydb. With the current Fedora policy and refpolicy, this function is called nearly 100,000 times per policy load. A single avtab node is only permitted to have a single specifier to describe the data it holds. As such, a check is performed to make sure only one specifier is set. Previously this was done via a for-loop. However, there is already an optimal function for finding the number of bits set (hamming weight) and on some architectures, dedicated instructions (popcount) which can be executed much more efficiently. Even when using -mcpu=generic on a x86-64 Fedora 38 VM, this commit results in a modest 2-4% speedup for policy loading due to a substantial reduction in the number of instructions executed. Signed-off-by: Jacob Satterfield <jsatterfield.linux@gmail.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: improve role transition hashingChristian Göttsche2023-09-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | The number of buckets is calculated by performing a binary AND against the mask of the hash table, which is one less than its size (which is a power of two). This leads to all top bits being discarded, e.g. with the Reference Policy on Debian there exists 376 entries, leading to a size of 512, discarding the top 23 bits. Use jhash to improve the hash table utilization: # current roletr: 376 entries and 124/512 buckets used, longest chain length 8, sum of chain length^2 1496 # patch roletr: 376 entries and 266/512 buckets used, longest chain length 4, sum of chain length^2 646 Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> [PM: line wrap in the commit description] Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: simplify avtab slot calculationChristian Göttsche2023-09-131-7/+1
| | | | | | | | | | | | | Instead of dividing by 8 and then performing log2 by hand, use a more readable calculation. The behavior of rounddown_pow_of_two() for an input of 0 is undefined, so handle that case and small values manually to achieve the same results. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: print sum of chain lengths^2 for hash tablesChristian Göttsche2023-09-134-3/+9
| | | | | | | | | | | | Print the sum of chain lengths squared as a metric for hash tables to provide more insights, similar to avtabs. While on it add a comma in the avtab message to improve readability of the output. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* selinux: Annotate struct sidtab_str_cache with __counted_byKees Cook2023-09-121-1/+1
| | | | | | | | | | | | | | | | | | | | | Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct sidtab_str_cache. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Eric Paris <eparis@parisplace.org> Cc: Ondrej Mosnacek <omosnace@redhat.com> Cc: selinux@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
* Merge tag 'selinux-pr-20230829' of ↵Linus Torvalds2023-08-3020-152/+147
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "Thirty three SELinux patches, which is a pretty big number for us, but there isn't really anything scary in here; in fact we actually manage to remove 10 lines of code with this :) - Promote the SELinux DEBUG_HASHES macro to CONFIG_SECURITY_SELINUX_DEBUG The DEBUG_HASHES macro was a buried SELinux specific preprocessor debug macro that was a problem waiting to happen. Promoting the debug macro to a proper Kconfig setting should help both improve the visibility of the feature as well enable improved test coverage. We've moved some additional debug functions under the CONFIG_SECURITY_SELINUX_DEBUG flag and we may see more work in the future. - Emit a pr_notice() message if virtual memory is executable by default As this impacts the SELinux access control policy enforcement, if the system's configuration is such that virtual memory is executable by default we print a single line notice to the console. - Drop avtab_search() in favor of avtab_search_node() Both functions are nearly identical so we removed avtab_search() and converted the callers to avtab_search_node(). - Add some SELinux network auditing helpers The helpers not only reduce a small amount of code duplication, but they provide an opportunity to improve UDP flood performance slightly by delaying initialization of the audit data in some cases. - Convert GFP_ATOMIC allocators to GFP_KERNEL when reading SELinux policy There were two SELinux policy load helper functions that were allocating memory using GFP_ATOMIC, they have been converted to GFP_KERNEL. - Quiet a KMSAN warning in selinux_inet_conn_request() A one-line error path (re)set patch that resolves a KMSAN warning. It is important to note that this doesn't represent a real bug in the current code, but it quiets KMSAN and arguably hardens the code against future changes. - Cleanup the policy capability accessor functions This is a follow-up to the patch which reverted SELinux to using a global selinux_state pointer. This patch cleans up some artifacts of that change and turns each accessor into a one-line READ_ONCE() call into the policy capabilities array. - A number of patches from Christian Göttsche Christian submitted almost two-thirds of the patches in this pull request as he worked to harden the SELinux code against type differences, variable overflows, etc. - Support for separating early userspace from the kernel in policy, with a later revert We did have a patch that added a new userspace initial SID which would allow SELinux to distinguish between early user processes created before the initial policy load and the kernel itself. Unfortunately additional post-merge testing revealed a problematic interaction with an old SELinux userspace on an old version of Ubuntu so we've reverted the patch until we can resolve the compatibility issue. - Remove some outdated comments dealing with LSM hook registration When we removed the runtime disable functionality we forgot to remove some old comments discussing the importance of LSM hook registration ordering. - Minor administrative changes Stephen Smalley updated his email address and "debranded" SELinux from "NSA SELinux" to simply "SELinux". We've come a long way from the original NSA submission and I would consider SELinux a true community project at this point so removing the NSA branding just makes sense" * tag 'selinux-pr-20230829' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: (33 commits) selinux: prevent KMSAN warning in selinux_inet_conn_request() selinux: use unsigned iterator in nlmsgtab code selinux: avoid implicit conversions in policydb code selinux: avoid implicit conversions in selinuxfs code selinux: make left shifts well defined selinux: update type for number of class permissions in services code selinux: avoid implicit conversions in avtab code selinux: revert SECINITSID_INIT support selinux: use GFP_KERNEL while reading binary policy selinux: update comment on selinux_hooks[] selinux: avoid implicit conversions in services code selinux: avoid implicit conversions in mls code selinux: use identical iterator type in hashtab_duplicate() selinux: move debug functions into debug configuration selinux: log about VM being executable by default selinux: fix a 0/NULL mistmatch in ad_net_init_from_iif() selinux: introduce SECURITY_SELINUX_DEBUG configuration selinux: introduce and use lsm_ad_net_init*() helpers selinux: update my email address selinux: add missing newlines in pr_err() statements ...
| * selinux: avoid implicit conversions in policydb codeChristian Göttsche2023-08-091-32/+37
| | | | | | | | | | | | | | | | | | | | | | Use the identical type for local variables, e.g. loop counters. Declare members of struct policydb_compat_info unsigned to consistently use unsigned iterators. They hold read-only non-negative numbers in the global variable policydb_compat. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
| * selinux: make left shifts well definedChristian Göttsche2023-08-091-6/+6
| | | | | | | | | | | | | | | | | | | | The loops upper bound represent the number of permissions used (for the current class or in general). The limit for this is 32, thus we might left shift of one less, 31. Shifting a base of 1 results in undefined behavior; use (u32)1 as base. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
| * selinux: update type for number of class permissions in services codeChristian Göttsche2023-08-092-2/+2
| | | | | | | | | | | | | | | | Security classes have only up to 32 permissions, hence using an u16 is sufficient (while improving padding in struct selinux_mapping). Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
| * selinux: avoid implicit conversions in avtab codeChristian Göttsche2023-08-091-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Return u32 from avtab_hash() instead of int, since the hashing is done on u32 and the result is used as an index on the hash array. Use the type of the limit in for loops. Avoid signed to unsigned conversion of multiplication result in avtab_hash_eval() and perform multiplication in destination type. Use unsigned loop iterator for index operations, to avoid sign extension. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
| * selinux: revert SECINITSID_INIT supportPaul Moore2023-08-091-27/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: use GFP_KERNEL while reading binary policyChristian Göttsche2023-08-081-5/+5
| | | | | | | | | | | | | | | | Use GFP_KERNEL instead of GFP_ATOMIC while reading a binary policy in sens_read() and cat_read(), similar to surrounding code. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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