1 files changed, 25 insertions, 2 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 16ef870fa75a..7733ef58aaca 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -151,6 +151,8 @@ static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
 #ifdef CONFIG_PROC_SYSCTL
 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
                   void __user *buffer, size_t *lenp, loff_t *ppos);
+static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
+                               void __user *buffer, size_t *lenp, loff_t *ppos);
 #endif
 
 static ctl_table root_table[];
@@ -174,6 +176,7 @@ extern ctl_table inotify_table[];
 int sysctl_legacy_va_layout;
 #endif
 
+
 static void *get_uts(ctl_table *table, int write)
 {
         char *which = table->data;
@@ -344,14 +347,16 @@ static ctl_table kern_table[] = {
                 .proc_handler   = &proc_dostring,
                 .strategy       = &sysctl_string,
         },
+#ifdef CONFIG_PROC_SYSCTL
         {
                 .ctl_name       = KERN_TAINTED,
                 .procname       = "tainted",
                 .data           = &tainted,
                 .maxlen         = sizeof(int),
-                .mode           = 0444,
-                .proc_handler   = &proc_dointvec,
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec_taint,
         },
+#endif
         {
                 .ctl_name       = KERN_CAP_BSET,
                 .procname       = "cap-bound",
@@ -1927,6 +1932,7 @@ int proc_dointvec(ctl_table *table, int write, struct file *filp,
 
 #define OP_SET  0
 #define OP_AND  1
+#define OP_OR   2
 
 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
                                       int *valp,
@@ -1938,6 +1944,7 @@ static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
                 switch(op) {
                 case OP_SET:    *valp = val; break;
                 case OP_AND:    *valp &= val; break;
+                case OP_OR:     *valp |= val; break;
                 }
         } else {
                 int val = *valp;
@@ -1970,6 +1977,22 @@ int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
                                 do_proc_dointvec_bset_conv,&op);
 }
 
+/*
+ *      Taint values can only be increased
+ */
+static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
+                               void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+        int op;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        op = OP_OR;
+        return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
+                                do_proc_dointvec_bset_conv,&op);
+}
+
 struct do_proc_dointvec_minmax_conv_param {
         int *min;
         int *max;