kernel/linux.git/security/selinux/include, branch v6.6.151

lsm: infrastructure management of the sock security

2026-08-03T09:15:36+00:00

[ Upstream commit 2aff9d20d50ac45dd13a013ef5231f4fb8912356 ] 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 Reviewed-by: Kees Cook Reviewed-by: John Johansen Acked-by: Stephen Smalley Signed-off-by: Casey Schaufler [PM: subject tweak] Signed-off-by: Paul Moore Stable-dep-of: 56acfeb10019 ("selinux: avoid sk_socket dereference in selinux_sctp_bind_connect()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

selinux: fix overlayfs mmap() and mprotect() access checks

2026-07-04T11:42:23+00:00

[ Upstream commit 82544d36b1729153c8aeb179e84750f0c085d3b1 ] The existing SELinux security model for overlayfs is to allow access if the current task is able to access the top level file (the "user" file) and the mounter's credentials are sufficient to access the lower level file (the "backing" file). Unfortunately, the current code does not properly enforce these access controls for both mmap() and mprotect() operations on overlayfs filesystems. This patch makes use of the newly created security_mmap_backing_file() LSM hook to provide the missing backing file enforcement for mmap() operations, and leverages the backing file API and new LSM blob to provide the necessary information to properly enforce the mprotect() access controls. Cc: stable@vger.kernel.org Acked-by: Amir Goldstein Signed-off-by: Paul Moore [backing_file_user_path() not available Mainline uses backing_file_user_path(file) to obtain the user-visible path from a backing file. The 6.6.y version uses &file->f_path directly] Signed-off-by: Cai Xinchen Signed-off-by: Sasha Levin

ima: Avoid blocking in RCU read-side critical section

2024-07-11T10:49:18+00:00

commit 9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 upstream. 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 Acked-by: John Johansen Reviewed-by: Mimi Zohar Reviewed-by: Casey Schaufler [PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case] Signed-off-by: Paul Moore Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman

selinux: revert SECINITSID_INIT support

2023-08-09T14:51:13+00:00

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 Signed-off-by: Paul Moore

selinux: avoid implicit conversions in services code

2023-08-04T02:19:57+00:00

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 [PM: cleanup extra whitespace in subject] Signed-off-by: Paul Moore

selinux: update my email address

2023-07-19T15:27:02+00:00

Update my email address; MAINTAINERS was updated some time ago. Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore

selinux: de-brand SELinux

2023-07-18T22:42:57+00:00

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 Signed-off-by: Paul Moore

selinux: avoid implicit conversions regarding enforcing status

2023-07-18T22:29:50+00:00

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 [PM: subject line tweaks] Signed-off-by: Paul Moore

selinux: consistently use u32 as sequence number type in the status code

2023-07-18T22:29:47+00:00

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 [PM: subject line tweaks] Signed-off-by: Paul Moore

selinux: introduce an initial SID for early boot processes

2023-07-10T18:23:56+00:00

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 Signed-off-by: Paul Moore