1 files changed, 10 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 913c5725cdb2..bb6ac471a784 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1306,6 +1306,16 @@ void show_user_instructions(struct pt_regs *regs)
 
         pc = regs->nip - (instructions_to_print * 3 / 4 * sizeof(int));
 
+        /*
+         * Make sure the NIP points at userspace, not kernel text/data or
+         * elsewhere.
+         */
+        if (!__access_ok(pc, instructions_to_print * sizeof(int), USER_DS)) {
+                pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",
+                        current->comm, current->pid);
+                return;
+        }
+
         pr_info("%s[%d]: code: ", current->comm, current->pid);
 
         for (i = 0; i < instructions_to_print; i++) {