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authorLinus Torvalds <torvalds@linux-foundation.org>2014-08-06 08:06:39 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-06 08:06:39 -0700
commitbb2cbf5e9367d8598fecd0c48dead69560750223 (patch)
treefb2c620451b90f41a31726bdd82077813f941e39 /kernel/fork.c
parente7fda6c4c3c1a7d6996dd75fd84670fa0b5d448f (diff)
parent478d085524c57cf4283699f529d5a4c22188ea69 (diff)
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Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris: "In this release: - PKCS#7 parser for the key management subsystem from David Howells - appoint Kees Cook as seccomp maintainer - bugfixes and general maintenance across the subsystem" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (94 commits) X.509: Need to export x509_request_asymmetric_key() netlabel: shorter names for the NetLabel catmap funcs/structs netlabel: fix the catmap walking functions netlabel: fix the horribly broken catmap functions netlabel: fix a problem when setting bits below the previously lowest bit PKCS#7: X.509 certificate issuer and subject are mandatory fields in the ASN.1 tpm: simplify code by using %*phN specifier tpm: Provide a generic means to override the chip returned timeouts tpm: missing tpm_chip_put in tpm_get_random() tpm: Properly clean sysfs entries in error path tpm: Add missing tpm_do_selftest to ST33 I2C driver PKCS#7: Use x509_request_asymmetric_key() Revert "selinux: fix the default socket labeling in sock_graft()" X.509: x509_request_asymmetric_keys() doesn't need string length arguments PKCS#7: fix sparse non static symbol warning KEYS: revert encrypted key change ima: add support for measuring and appraising firmware firmware_class: perform new LSM checks security: introduce kernel_fw_from_file hook PKCS#7: Missing inclusion of linux/err.h ...
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c49
1 files changed, 48 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 5f1bf3bebb4f..fbd3497b221f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -315,6 +315,15 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
goto free_ti;
tsk->stack = ti;
+#ifdef CONFIG_SECCOMP
+ /*
+ * We must handle setting up seccomp filters once we're under
+ * the sighand lock in case orig has changed between now and
+ * then. Until then, filter must be NULL to avoid messing up
+ * the usage counts on the error path calling free_task.
+ */
+ tsk->seccomp.filter = NULL;
+#endif
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
@@ -1081,6 +1090,39 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
return 0;
}
+static void copy_seccomp(struct task_struct *p)
+{
+#ifdef CONFIG_SECCOMP
+ /*
+ * Must be called with sighand->lock held, which is common to
+ * all threads in the group. Holding cred_guard_mutex is not
+ * needed because this new task is not yet running and cannot
+ * be racing exec.
+ */
+ BUG_ON(!spin_is_locked(&current->sighand->siglock));
+
+ /* Ref-count the new filter user, and assign it. */
+ get_seccomp_filter(current);
+ p->seccomp = current->seccomp;
+
+ /*
+ * Explicitly enable no_new_privs here in case it got set
+ * between the task_struct being duplicated and holding the
+ * sighand lock. The seccomp state and nnp must be in sync.
+ */
+ if (task_no_new_privs(current))
+ task_set_no_new_privs(p);
+
+ /*
+ * If the parent gained a seccomp mode after copying thread
+ * flags and between before we held the sighand lock, we have
+ * to manually enable the seccomp thread flag here.
+ */
+ if (p->seccomp.mode != SECCOMP_MODE_DISABLED)
+ set_tsk_thread_flag(p, TIF_SECCOMP);
+#endif
+}
+
SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
{
current->clear_child_tid = tidptr;
@@ -1195,7 +1237,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto fork_out;
ftrace_graph_init_task(p);
- get_seccomp_filter(p);
rt_mutex_init_task(p);
@@ -1435,6 +1476,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
spin_lock(&current->sighand->siglock);
/*
+ * Copy seccomp details explicitly here, in case they were changed
+ * before holding sighand lock.
+ */
+ copy_seccomp(p);
+
+ /*
* Process group and session signals need to be delivered to just the
* parent before the fork or both the parent and the child after the
* fork. Restart if a signal comes in before we add the new process to