1 files changed, 44 insertions, 25 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index bc86bb32e126..c0bb32414b17 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -117,6 +117,7 @@ static int neg_one = -1;
 static int zero;
 static int __maybe_unused one = 1;
 static int __maybe_unused two = 2;
+static int __maybe_unused three = 3;
 static unsigned long one_ul = 1;
 static int one_hundred = 100;
 #ifdef CONFIG_PRINTK
@@ -169,8 +170,14 @@ static int proc_taint(struct ctl_table *table, int write,
                                void __user *buffer, size_t *lenp, loff_t *ppos);
 #endif
 
+#ifdef CONFIG_PRINTK
+static int proc_dmesg_restrict(struct ctl_table *table, int write,
+                                void __user *buffer, size_t *lenp, loff_t *ppos);
+#endif
+
 #ifdef CONFIG_MAGIC_SYSRQ
-static int __sysrq_enabled; /* Note: sysrq code ises it's own private copy */
+/* Note: sysrq code uses it's own private copy */
+static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
 
 static int sysrq_sysctl_handler(ctl_table *table, int write,
                                 void __user *buffer, size_t *lenp,
@@ -193,9 +200,9 @@ static int sysrq_sysctl_handler(ctl_table *table, int write,
 static struct ctl_table root_table[];
 static struct ctl_table_root sysctl_table_root;
 static struct ctl_table_header root_table_header = {
-        .count = 1,
+        {{.count = 1,
         .ctl_table = root_table,
-        .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
+        .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
         .root = &sysctl_table_root,
         .set = &sysctl_table_root.default_set,
 };
@@ -360,20 +367,13 @@ static struct ctl_table kern_table[] = {
                 .mode           = 0644,
                 .proc_handler   = sched_rt_handler,
         },
-        {
-                .procname       = "sched_compat_yield",
-                .data           = &sysctl_sched_compat_yield,
-                .maxlen         = sizeof(unsigned int),
-                .mode           = 0644,
-                .proc_handler   = proc_dointvec,
-        },
 #ifdef CONFIG_SCHED_AUTOGROUP
         {
                 .procname       = "sched_autogroup_enabled",
                 .data           = &sysctl_sched_autogroup_enabled,
                 .maxlen         = sizeof(unsigned int),
                 .mode           = 0644,
-                .proc_handler   = proc_dointvec,
+                .proc_handler   = proc_dointvec_minmax,
                 .extra1         = &zero,
                 .extra2         = &one,
         },
@@ -712,7 +712,7 @@ static struct ctl_table kern_table[] = {
                 .data           = &kptr_restrict,
                 .maxlen         = sizeof(int),
                 .mode           = 0644,
-                .proc_handler   = proc_dointvec_minmax,
+                .proc_handler   = proc_dmesg_restrict,
                 .extra1         = &zero,
                 .extra2         = &two,
         },
@@ -947,7 +947,7 @@ static struct ctl_table kern_table[] = {
                 .data           = &sysctl_perf_event_sample_rate,
                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
                 .mode           = 0644,
-                .proc_handler   = proc_dointvec,
+                .proc_handler   = perf_proc_update_handler,
         },
 #endif
 #ifdef CONFIG_KMEMCHECK
@@ -977,14 +977,18 @@ static struct ctl_table vm_table[] = {
                 .data           = &sysctl_overcommit_memory,
                 .maxlen         = sizeof(sysctl_overcommit_memory),
                 .mode           = 0644,
-                .proc_handler   = proc_dointvec,
+                .proc_handler   = proc_dointvec_minmax,
+                .extra1         = &zero,
+                .extra2         = &two,
         },
         {
                 .procname       = "panic_on_oom",
                 .data           = &sysctl_panic_on_oom,
                 .maxlen         = sizeof(sysctl_panic_on_oom),
                 .mode           = 0644,
-                .proc_handler   = proc_dointvec,
+                .proc_handler   = proc_dointvec_minmax,
+                .extra1         = &zero,
+                .extra2         = &two,
         },
         {
                 .procname       = "oom_kill_allocating_task",
@@ -1012,7 +1016,8 @@ static struct ctl_table vm_table[] = {
                 .data           = &page_cluster,
                 .maxlen         = sizeof(int),
                 .mode           = 0644,
-                .proc_handler   = proc_dointvec,
+                .proc_handler   = proc_dointvec_minmax,
+                .extra1         = &zero,
         },
         {
                 .procname       = "dirty_background_ratio",
@@ -1060,7 +1065,8 @@ static struct ctl_table vm_table[] = {
                 .data           = &dirty_expire_interval,
                 .maxlen         = sizeof(dirty_expire_interval),
                 .mode           = 0644,
-                .proc_handler   = proc_dointvec,
+                .proc_handler   = proc_dointvec_minmax,
+                .extra1         = &zero,
         },
         {
                 .procname       = "nr_pdflush_threads",
@@ -1136,6 +1142,8 @@ static struct ctl_table vm_table[] = {
                 .maxlen         = sizeof(int),
                 .mode           = 0644,
                 .proc_handler   = drop_caches_sysctl_handler,
+                .extra1         = &one,
+                .extra2         = &three,
         },
 #ifdef CONFIG_COMPACTION
         {
@@ -1566,11 +1574,16 @@ void sysctl_head_get(struct ctl_table_header *head)
         spin_unlock(&sysctl_lock);
 }
 
+static void free_head(struct rcu_head *rcu)
+{
+        kfree(container_of(rcu, struct ctl_table_header, rcu));
+}
+
 void sysctl_head_put(struct ctl_table_header *head)
 {
         spin_lock(&sysctl_lock);
         if (!--head->count)
-                kfree(head);
+                call_rcu(&head->rcu, free_head);
         spin_unlock(&sysctl_lock);
 }
 
@@ -1684,13 +1697,8 @@ static int test_perm(int mode, int op)
 
 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
 {
-        int error;
         int mode;
 
-        error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
-        if (error)
-                return error;
-
         if (root->permissions)
                 mode = root->permissions(root, current->nsproxy, table);
         else
@@ -1947,10 +1955,10 @@ void unregister_sysctl_table(struct ctl_table_header * header)
         start_unregistering(header);
         if (!--header->parent->count) {
                 WARN_ON(1);
-                kfree(header->parent);
+                call_rcu(&header->parent->rcu, free_head);
         }
         if (!--header->count)
-                kfree(header);
+                call_rcu(&header->rcu, free_head);
         spin_unlock(&sysctl_lock);
 }
 
@@ -2391,6 +2399,17 @@ static int proc_taint(struct ctl_table *table, int write,
         return err;
 }
 
+#ifdef CONFIG_PRINTK
+static int proc_dmesg_restrict(struct ctl_table *table, int write,
+                                void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+        if (write && !capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+}
+#endif
+
 struct do_proc_dointvec_minmax_conv_param {
         int *min;
         int *max;