3.16.58-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Kees Cook <keesc...@chromium.org>
commit 3b23dd12846215eff4afb073366b80c0c4d7543e upstream.
Separates the two mode setting paths to make things more readable with
fewer #ifdefs within function bodies.
Signed-off-by: Kees Cook <keesc...@chromium.org>
Reviewed-by: Oleg Nesterov <o...@redhat.com>
Reviewed-by: Andy Lutomirski <l...@amacapital.net>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
kernel/seccomp.c | 71 ++++++++++++++++++++++++++++++++----------------
1 file changed, 48 insertions(+), 23 deletions(-)
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -489,48 +489,66 @@ long prctl_get_seccomp(void)
}
/**
- * seccomp_set_mode: internal function for setting seccomp mode
- * @seccomp_mode: requested mode to use
- * @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER
- *
- * This function may be called repeatedly with a @seccomp_mode of
- * SECCOMP_MODE_FILTER to install additional filters. Every filter
- * successfully installed will be evaluated (in reverse order) for each system
- * call the task makes.
+ * seccomp_set_mode_strict: internal function for setting strict seccomp
*
* Once current->seccomp.mode is non-zero, it may not be changed.
*
* Returns 0 on success or -EINVAL on failure.
*/
-static long seccomp_set_mode(unsigned long seccomp_mode, char __user *filter)
+static long seccomp_set_mode_strict(void)
{
+ const unsigned long seccomp_mode = SECCOMP_MODE_STRICT;
long ret = -EINVAL;
if (!seccomp_may_assign_mode(seccomp_mode))
goto out;
- switch (seccomp_mode) {
- case SECCOMP_MODE_STRICT:
- ret = 0;
#ifdef TIF_NOTSC
- disable_TSC();
+ disable_TSC();
#endif
- break;
+ seccomp_assign_mode(seccomp_mode);
+ ret = 0;
+
+out:
+
+ return ret;
+}
+
#ifdef CONFIG_SECCOMP_FILTER
- case SECCOMP_MODE_FILTER:
- ret = seccomp_attach_user_filter(filter);
- if (ret)
- goto out;
- break;
-#endif
- default:
+/**
+ * seccomp_set_mode_filter: internal function for setting seccomp filter
+ * @filter: struct sock_fprog containing filter
+ *
+ * This function may be called repeatedly to install additional filters.
+ * Every filter successfully installed will be evaluated (in reverse order)
+ * for each system call the task makes.
+ *
+ * Once current->seccomp.mode is non-zero, it may not be changed.
+ *
+ * Returns 0 on success or -EINVAL on failure.
+ */
+static long seccomp_set_mode_filter(char __user *filter)
+{
+ const unsigned long seccomp_mode = SECCOMP_MODE_FILTER;
+ long ret = -EINVAL;
+
+ if (!seccomp_may_assign_mode(seccomp_mode))
+ goto out;
+
+ ret = seccomp_attach_user_filter(filter);
+ if (ret)
goto out;
- }
seccomp_assign_mode(seccomp_mode);
out:
return ret;
}
+#else
+static inline long seccomp_set_mode_filter(char __user *filter)
+{
+ return -EINVAL;
+}
+#endif
/**
* prctl_set_seccomp: configures current->seccomp.mode
@@ -541,5 +559,12 @@ out:
*/
long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter)
{
- return seccomp_set_mode(seccomp_mode, filter);
+ switch (seccomp_mode) {
+ case SECCOMP_MODE_STRICT:
+ return seccomp_set_mode_strict();
+ case SECCOMP_MODE_FILTER:
+ return seccomp_set_mode_filter(filter);
+ default:
+ return -EINVAL;
+ }
}
