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authorLinus Torvalds <torvalds@linux-foundation.org>2019-03-07 11:44:01 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-07 11:44:01 -0800
commitae5906ceee038ea29ff5162d1bcd18fb50af8b94 (patch)
tree841a11c6d3c3afcf7e4d57be370ebcf57aab214a /kernel
parent1fc1cd8399ab5541a488a7e47b2f21537dd76c2d (diff)
parent468e91cecb3218afd684b8c422490dfebe0691bb (diff)
downloadlinux-ae5906ceee038ea29ff5162d1bcd18fb50af8b94.tar.bz2
Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris: - Extend LSM stacking to allow sharing of cred, file, ipc, inode, and task blobs. This paves the way for more full-featured LSMs to be merged, and is specifically aimed at LandLock and SARA LSMs. This work is from Casey and Kees. - There's a new LSM from Micah Morton: "SafeSetID gates the setid family of syscalls to restrict UID/GID transitions from a given UID/GID to only those approved by a system-wide whitelist." This feature is currently shipping in ChromeOS. * 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (62 commits) keys: fix missing __user in KEYCTL_PKEY_QUERY LSM: Update list of SECURITYFS users in Kconfig LSM: Ignore "security=" when "lsm=" is specified LSM: Update function documentation for cap_capable security: mark expected switch fall-throughs and add a missing break tomoyo: Bump version. LSM: fix return value check in safesetid_init_securityfs() LSM: SafeSetID: add selftest LSM: SafeSetID: remove unused include LSM: SafeSetID: 'depend' on CONFIG_SECURITY LSM: Add 'name' field for SafeSetID in DEFINE_LSM LSM: add SafeSetID module that gates setid calls LSM: add SafeSetID module that gates setid calls tomoyo: Allow multiple use_group lines. tomoyo: Coding style fix. tomoyo: Swicth from cred->security to task_struct->security. security: keys: annotate implicit fall throughs security: keys: annotate implicit fall throughs security: keys: annotate implicit fall through capabilities:: annotate implicit fall through ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/capability.c45
-rw-r--r--kernel/cred.c13
-rw-r--r--kernel/seccomp.c4
-rw-r--r--kernel/sys.c10
4 files changed, 40 insertions, 32 deletions
diff --git a/kernel/capability.c b/kernel/capability.c
index 1e1c0236f55b..1444f3954d75 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -93,9 +93,7 @@ static int cap_validate_magic(cap_user_header_t header, unsigned *tocopy)
break;
case _LINUX_CAPABILITY_VERSION_2:
warn_deprecated_v2();
- /*
- * fall through - v3 is otherwise equivalent to v2.
- */
+ /* fall through - v3 is otherwise equivalent to v2. */
case _LINUX_CAPABILITY_VERSION_3:
*tocopy = _LINUX_CAPABILITY_U32S_3;
break;
@@ -299,7 +297,7 @@ bool has_ns_capability(struct task_struct *t,
int ret;
rcu_read_lock();
- ret = security_capable(__task_cred(t), ns, cap);
+ ret = security_capable(__task_cred(t), ns, cap, CAP_OPT_NONE);
rcu_read_unlock();
return (ret == 0);
@@ -340,7 +338,7 @@ bool has_ns_capability_noaudit(struct task_struct *t,
int ret;
rcu_read_lock();
- ret = security_capable_noaudit(__task_cred(t), ns, cap);
+ ret = security_capable(__task_cred(t), ns, cap, CAP_OPT_NOAUDIT);
rcu_read_unlock();
return (ret == 0);
@@ -363,7 +361,9 @@ bool has_capability_noaudit(struct task_struct *t, int cap)
return has_ns_capability_noaudit(t, &init_user_ns, cap);
}
-static bool ns_capable_common(struct user_namespace *ns, int cap, bool audit)
+static bool ns_capable_common(struct user_namespace *ns,
+ int cap,
+ unsigned int opts)
{
int capable;
@@ -372,8 +372,7 @@ static bool ns_capable_common(struct user_namespace *ns, int cap, bool audit)
BUG();
}
- capable = audit ? security_capable(current_cred(), ns, cap) :
- security_capable_noaudit(current_cred(), ns, cap);
+ capable = security_capable(current_cred(), ns, cap, opts);
if (capable == 0) {
current->flags |= PF_SUPERPRIV;
return true;
@@ -394,7 +393,7 @@ static bool ns_capable_common(struct user_namespace *ns, int cap, bool audit)
*/
bool ns_capable(struct user_namespace *ns, int cap)
{
- return ns_capable_common(ns, cap, true);
+ return ns_capable_common(ns, cap, CAP_OPT_NONE);
}
EXPORT_SYMBOL(ns_capable);
@@ -412,11 +411,30 @@ EXPORT_SYMBOL(ns_capable);
*/
bool ns_capable_noaudit(struct user_namespace *ns, int cap)
{
- return ns_capable_common(ns, cap, false);
+ return ns_capable_common(ns, cap, CAP_OPT_NOAUDIT);
}
EXPORT_SYMBOL(ns_capable_noaudit);
/**
+ * ns_capable_setid - Determine if the current task has a superior capability
+ * in effect, while signalling that this check is being done from within a
+ * setid syscall.
+ * @ns: The usernamespace we want the capability in
+ * @cap: The capability to be tested for
+ *
+ * Return true if the current task has the given superior capability currently
+ * available for use, false if not.
+ *
+ * This sets PF_SUPERPRIV on the task if the capability is available on the
+ * assumption that it's about to be used.
+ */
+bool ns_capable_setid(struct user_namespace *ns, int cap)
+{
+ return ns_capable_common(ns, cap, CAP_OPT_INSETID);
+}
+EXPORT_SYMBOL(ns_capable_setid);
+
+/**
* capable - Determine if the current task has a superior capability in effect
* @cap: The capability to be tested for
*
@@ -448,10 +466,11 @@ EXPORT_SYMBOL(capable);
bool file_ns_capable(const struct file *file, struct user_namespace *ns,
int cap)
{
+
if (WARN_ON_ONCE(!cap_valid(cap)))
return false;
- if (security_capable(file->f_cred, ns, cap) == 0)
+ if (security_capable(file->f_cred, ns, cap, CAP_OPT_NONE) == 0)
return true;
return false;
@@ -500,10 +519,12 @@ bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns)
{
int ret = 0; /* An absent tracer adds no restrictions */
const struct cred *cred;
+
rcu_read_lock();
cred = rcu_dereference(tsk->ptracer_cred);
if (cred)
- ret = security_capable_noaudit(cred, ns, CAP_SYS_PTRACE);
+ ret = security_capable(cred, ns, CAP_SYS_PTRACE,
+ CAP_OPT_NOAUDIT);
rcu_read_unlock();
return (ret == 0);
}
diff --git a/kernel/cred.c b/kernel/cred.c
index 21f4a97085b4..45d77284aed0 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -760,19 +760,6 @@ bool creds_are_invalid(const struct cred *cred)
{
if (cred->magic != CRED_MAGIC)
return true;
-#ifdef CONFIG_SECURITY_SELINUX
- /*
- * cred->security == NULL if security_cred_alloc_blank() or
- * security_prepare_creds() returned an error.
- */
- if (selinux_is_enabled() && cred->security) {
- if ((unsigned long) cred->security < PAGE_SIZE)
- return true;
- if ((*(u32 *)cred->security & 0xffffff00) ==
- (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8))
- return true;
- }
-#endif
return false;
}
EXPORT_SYMBOL(creds_are_invalid);
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index a43c601ac252..54a0347ca812 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -445,8 +445,8 @@ static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog)
* behavior of privileged children.
*/
if (!task_no_new_privs(current) &&
- security_capable_noaudit(current_cred(), current_user_ns(),
- CAP_SYS_ADMIN) != 0)
+ security_capable(current_cred(), current_user_ns(),
+ CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) != 0)
return ERR_PTR(-EACCES);
/* Allocate a new seccomp_filter */
diff --git a/kernel/sys.c b/kernel/sys.c
index f7eb62eceb24..c5f875048aef 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -516,7 +516,7 @@ long __sys_setreuid(uid_t ruid, uid_t euid)
new->uid = kruid;
if (!uid_eq(old->uid, kruid) &&
!uid_eq(old->euid, kruid) &&
- !ns_capable(old->user_ns, CAP_SETUID))
+ !ns_capable_setid(old->user_ns, CAP_SETUID))
goto error;
}
@@ -525,7 +525,7 @@ long __sys_setreuid(uid_t ruid, uid_t euid)
if (!uid_eq(old->uid, keuid) &&
!uid_eq(old->euid, keuid) &&
!uid_eq(old->suid, keuid) &&
- !ns_capable(old->user_ns, CAP_SETUID))
+ !ns_capable_setid(old->user_ns, CAP_SETUID))
goto error;
}
@@ -584,7 +584,7 @@ long __sys_setuid(uid_t uid)
old = current_cred();
retval = -EPERM;
- if (ns_capable(old->user_ns, CAP_SETUID)) {
+ if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
new->suid = new->uid = kuid;
if (!uid_eq(kuid, old->uid)) {
retval = set_user(new);
@@ -646,7 +646,7 @@ long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
old = current_cred();
retval = -EPERM;
- if (!ns_capable(old->user_ns, CAP_SETUID)) {
+ if (!ns_capable_setid(old->user_ns, CAP_SETUID)) {
if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
!uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
goto error;
@@ -814,7 +814,7 @@ long __sys_setfsuid(uid_t uid)
if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
- ns_capable(old->user_ns, CAP_SETUID)) {
+ ns_capable_setid(old->user_ns, CAP_SETUID)) {
if (!uid_eq(kuid, old->fsuid)) {
new->fsuid = kuid;
if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)