From fe81536af3978f26a1383e4da7f135b973eb4209 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Mon, 31 Mar 2025 12:47:07 +0200 Subject: landlock: Remove incorrect warning MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit landlock_put_hierarchy() can be called when an error occurs in landlock_merge_ruleset() due to insufficient memory. In this case, the domain's audit details might not have been allocated yet, which would cause landlock_free_hierarchy_details() to print a warning (but still safely handle this case). We could keep the WARN_ON_ONCE(!hierarchy) but it's not worth it for this kind of function, so let's remove it entirely. Cc: Paul Moore Reported-by: syzbot+8bca99e91de7e060e4ea@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20250331104709.897062-1-mic@digikod.net Reviewed-by: Günther Noack Signed-off-by: Mickaël Salaün --- security/landlock/domain.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security') diff --git a/security/landlock/domain.h b/security/landlock/domain.h index ed0d348e214c..7fb70b25f85a 100644 --- a/security/landlock/domain.h +++ b/security/landlock/domain.h @@ -130,7 +130,7 @@ int landlock_init_hierarchy_log(struct landlock_hierarchy *const hierarchy); static inline void landlock_free_hierarchy_details(struct landlock_hierarchy *const hierarchy) { - if (WARN_ON_ONCE(!hierarchy || !hierarchy->details)) + if (!hierarchy || !hierarchy->details) return; put_pid(hierarchy->details->pid); -- cgit v1.2.3 From 4767af82a08ffaa5e55fe71febfa8cdef201b620 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Thu, 10 Apr 2025 19:17:21 +0200 Subject: landlock: Log the TGID of the domain creator MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As for other Audit's "pid" fields, Landlock should use the task's TGID instead of its TID. Fix this issue by keeping a reference to the TGID of the domain creator. Existing tests already check for the PID but only with the thread group leader, so always the TGID. A following patch adds dedicated tests for non-leader thread. Remove the current_real_cred() check which does not make sense because we only reference a struct pid, whereas a previous version did reference a struct cred instead. Cc: Christian Brauner Cc: Paul Moore Reviewed-by: Günther Noack Link: https://lore.kernel.org/r/20250410171725.1265860-1-mic@digikod.net Signed-off-by: Mickaël Salaün --- security/landlock/domain.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'security') diff --git a/security/landlock/domain.c b/security/landlock/domain.c index bae2e9909013..a647b68e8d06 100644 --- a/security/landlock/domain.c +++ b/security/landlock/domain.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include "access.h" @@ -99,8 +100,7 @@ static struct landlock_details *get_current_details(void) return ERR_PTR(-ENOMEM); memcpy(details->exe_path, path_str, path_size); - WARN_ON_ONCE(current_cred() != current_real_cred()); - details->pid = get_pid(task_pid(current)); + details->pid = get_pid(task_tgid(current)); details->uid = from_kuid(&init_user_ns, current_uid()); get_task_comm(details->comm, current); return details; -- cgit v1.2.3 From f5c68a4e84f9feca3be578199ec648b676db2030 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 9 Apr 2025 08:11:58 -0700 Subject: hardening: Disable GCC randstruct for COMPILE_TEST There is a GCC crash bug in the randstruct for latest GCC versions that is being tickled by landlock[1]. Temporarily disable GCC randstruct for COMPILE_TEST builds to unbreak CI systems for the coming -rc2. This can be restored once the bug is fixed. Suggested-by: Mark Brown Link: https://lore.kernel.org/all/20250407-kbuild-disable-gcc-plugins-v1-1-5d46ae583f5e@kernel.org/ [1] Acked-by: Mark Brown Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/20250409151154.work.872-kees@kernel.org Signed-off-by: Kees Cook --- security/Kconfig.hardening | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security') diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index c17366ce8224..3fe9d7b945c4 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -344,7 +344,7 @@ config CC_HAS_RANDSTRUCT choice prompt "Randomize layout of sensitive kernel structures" - default RANDSTRUCT_FULL if COMPILE_TEST && (GCC_PLUGINS || CC_HAS_RANDSTRUCT) + default RANDSTRUCT_FULL if COMPILE_TEST && CC_HAS_RANDSTRUCT default RANDSTRUCT_NONE help If you enable this, the layouts of structures that are entirely -- cgit v1.2.3 From 50492f942c281af4a48f8028f8409d7b8f2655d9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Wed, 16 Apr 2025 17:47:11 +0200 Subject: landlock: Fix documentation for landlock_create_ruleset(2) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Move and fix the flags documentation, and improve formatting. It makes more sense and it eases maintenance to document syscall flags in landlock.h, where they are defined. This is already the case for landlock_restrict_self(2)'s flags. The flags are now rendered like the syscall's parameters and description. Cc: Günther Noack Cc: Paul Moore Link: https://lore.kernel.org/r/20250416154716.1799902-1-mic@digikod.net Signed-off-by: Mickaël Salaün --- security/landlock/syscalls.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'security') diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c index 54a9f29e6ebb..9515dc92b99f 100644 --- a/security/landlock/syscalls.c +++ b/security/landlock/syscalls.c @@ -169,20 +169,16 @@ const int landlock_abi_version = 7; * the new ruleset. * @size: Size of the pointed &struct landlock_ruleset_attr (needed for * backward and forward compatibility). - * @flags: Supported value: + * @flags: Supported values: + * * - %LANDLOCK_CREATE_RULESET_VERSION * - %LANDLOCK_CREATE_RULESET_ERRATA * * This system call enables to create a new Landlock ruleset, and returns the * related file descriptor on success. * - * If @flags is %LANDLOCK_CREATE_RULESET_VERSION and @attr is NULL and @size is - * 0, then the returned value is the highest supported Landlock ABI version - * (starting at 1). - * - * If @flags is %LANDLOCK_CREATE_RULESET_ERRATA and @attr is NULL and @size is - * 0, then the returned value is a bitmask of fixed issues for the current - * Landlock ABI version. + * If %LANDLOCK_CREATE_RULESET_VERSION or %LANDLOCK_CREATE_RULESET_ERRATA is + * set, then @attr must be NULL and @size must be 0. * * Possible returned errors are: * @@ -191,6 +187,9 @@ const int landlock_abi_version = 7; * - %E2BIG: @attr or @size inconsistencies; * - %EFAULT: @attr or @size inconsistencies; * - %ENOMSG: empty &landlock_ruleset_attr.handled_access_fs. + * + * .. kernel-doc:: include/uapi/linux/landlock.h + * :identifiers: landlock_create_ruleset_flags */ SYSCALL_DEFINE3(landlock_create_ruleset, const struct landlock_ruleset_attr __user *const, attr, -- cgit v1.2.3 From 25b1fc1cdc8931cf26e8d169f65ad07dfd653ca2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Wed, 16 Apr 2025 17:47:12 +0200 Subject: landlock: Fix documentation for landlock_restrict_self(2) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix, deduplicate, and improve rendering of landlock_restrict_self(2)'s flags documentation. The flags are now rendered like the syscall's parameters and description. Cc: Günther Noack Cc: Paul Moore Link: https://lore.kernel.org/r/20250416154716.1799902-2-mic@digikod.net Signed-off-by: Mickaël Salaün --- security/landlock/syscalls.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'security') diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c index 9515dc92b99f..b9561e3417ae 100644 --- a/security/landlock/syscalls.c +++ b/security/landlock/syscalls.c @@ -451,18 +451,15 @@ SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, * @ruleset_fd: File descriptor tied to the ruleset to merge with the target. * @flags: Supported values: * - * - %LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF - * - %LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON - * - %LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF + * - %LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF + * - %LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON + * - %LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF * * This system call enables to enforce a Landlock ruleset on the current * thread. Enforcing a ruleset requires that the task has %CAP_SYS_ADMIN in its * namespace or is running with no_new_privs. This avoids scenarios where * unprivileged tasks can affect the behavior of privileged children. * - * It is allowed to only pass the %LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF - * flag with a @ruleset_fd value of -1. - * * Possible returned errors are: * * - %EOPNOTSUPP: Landlock is supported by the kernel but disabled at boot time; @@ -474,6 +471,9 @@ SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, * %CAP_SYS_ADMIN in its namespace. * - %E2BIG: The maximum number of stacked rulesets is reached for the current * thread. + * + * .. kernel-doc:: include/uapi/linux/landlock.h + * :identifiers: landlock_restrict_self_flags */ SYSCALL_DEFINE2(landlock_restrict_self, const int, ruleset_fd, const __u32, flags) -- cgit v1.2.3 From 30d68cb0c37ebe2dc63aa1d46a28b9163e61caa2 Mon Sep 17 00:00:00 2001 From: Frederick Lawler Date: Thu, 27 Mar 2025 11:09:11 -0500 Subject: ima: process_measurement() needlessly takes inode_lock() on MAY_READ On IMA policy update, if a measure rule exists in the policy, IMA_MEASURE is set for ima_policy_flags which makes the violation_check variable always true. Coupled with a no-action on MAY_READ for a FILE_CHECK call, we're always taking the inode_lock(). This becomes a performance problem for extremely heavy read-only workloads. Therefore, prevent this only in the case there's no action to be taken. Signed-off-by: Frederick Lawler Acked-by: Roberto Sassu Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'security') diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index f3e7ac513db3..f99ab1a3b0f0 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -245,7 +245,9 @@ static int process_measurement(struct file *file, const struct cred *cred, &allowed_algos); violation_check = ((func == FILE_CHECK || func == MMAP_CHECK || func == MMAP_CHECK_REQPROT) && - (ima_policy_flag & IMA_MEASURE)); + (ima_policy_flag & IMA_MEASURE) && + ((action & IMA_MEASURE) || + (file->f_mode & FMODE_WRITE))); if (!action && !violation_check) return 0; -- cgit v1.2.3