linux/security
Justin Suess 6887c03bf2
landlock: Add LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS
Add a landlock_restrict_self(2) flag to set the no_new_privs attribute
of the calling thread only after enforcement of the ruleset:
no_new_privs is set if and only if the call succeeds.  This removes the
need for a prior prctl(2) PR_SET_NO_NEW_PRIVS call and guarantees that
a failed enforcement leaves the attribute unchanged.

Because no_new_privs is set by the call itself, the no_new_privs /
CAP_SYS_ADMIN requirement of landlock_restrict_self(2) is fulfilled by
construction, and the related EPERM check is skipped.

Unlike LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF, this flag always
requires a valid ruleset: with a ruleset_fd of -1, such a call would be
nothing more than a Landlock-flavored prctl(2) PR_SET_NO_NEW_PRIVS, and
there is no valid use case for setting no_new_privs (possibly with
LANDLOCK_RESTRICT_SELF_TSYNC) without also enforcing Landlock
restrictions.  Rejecting these calls also keeps the option of giving
them a meaning later.

The attribute is only set past the last point of failure, just before
committing the new credentials.  When combined with
LANDLOCK_RESTRICT_SELF_TSYNC, no_new_privs is set on the sibling threads
as well, in their commit phase, with the same ordering.

Bump the Landlock ABI version to 11, and include the minimal related
test changes to keep the tests bisectable.

Cc: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Justin Suess <utilityemal77@gmail.com>
Link: https://patch.msgid.link/20260809212459.2427878-1-utilityemal77@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-15 09:14:46 +02:00
..
apparmor apparmor: advertise the tcp fast open fix is applied 2026-06-23 22:15:15 -07:00
bpf bpf: Reject BPF_MAP_TYPE_INODE_STORAGE creation if BPF LSM is uninitialized 2026-06-30 16:31:56 +02:00
integrity ima: Support staging and deleting N measurements records 2026-06-08 11:43:34 -04:00
ipe treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
keys keys: make keyring key-chunk byte order agree with keyring_diff_objects() 2026-07-23 18:23:39 +03:00
landlock landlock: Add LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS 2026-08-15 09:14:46 +02:00
loadpin Convert 'alloc_flex' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
lockdown lockdown: move initcalls to the LSM framework 2025-10-22 19:24:27 -04:00
safesetid Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
selinux selinux: fix incorrect execmem checks on overlayfs 2026-07-14 18:10:20 -04:00
smack security,fs,nfs,net: update security_inode_listsecurity() interface 2026-05-01 11:29:33 -04:00
tomoyo tomoyo: use u64 for holding inode->i_ino value 2026-04-15 00:00:10 +09:00
yama Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
commoncap_test.c security: Add KUnit tests for kuid_root_in_ns and vfsuid_root_in_currentns 2026-01-09 11:28:28 -06:00
commoncap.c security: Add KUnit tests for kuid_root_in_ns and vfsuid_root_in_currentns 2026-01-09 11:28:28 -06:00
device_cgroup.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
inode.c securityfs: use kstrdup_const() to manage symlink targets 2026-03-17 17:13:36 -04:00
Kconfig proc: make PROC_MEM_FORCE_PTRACE the Kconfig default 2026-04-13 09:12:37 -07:00
Kconfig.hardening security/Kconfig.hardening: Remove tautological condition from CC_HAS_RANDSTRUCT 2026-05-27 15:20:04 -07:00
lsm_audit.c treewide: change inode->i_ino from unsigned long to u64 2026-03-06 14:31:28 +01:00
lsm_init.c lsm: add backing_file LSM hooks 2026-04-03 16:53:50 -04:00
lsm_notifier.c lsm: split the notifier code out into lsm_notifier.c 2025-10-22 19:24:15 -04:00
lsm_syscalls.c lsm: hold cred_guard_mutex for lsm_set_self_attr() 2026-05-14 16:47:59 -04:00
lsm.h lsm: add backing_file LSM hooks 2026-04-03 16:53:50 -04:00
Makefile lsm: split the init code out into lsm_init.c 2025-10-22 19:24:16 -04:00
min_addr.c lsm: preserve /proc/sys/vm/mmap_min_addr when !CONFIG_SECURITY 2026-01-29 13:56:53 -05:00
security.c security,fs,nfs,net: update security_inode_listsecurity() interface 2026-05-01 11:29:33 -04:00