[PATCH] x86-64: Check return value of putreg in PTRACE_SETREGS

This means if an illegal value is set for the segment registers there
ptrace will error out now with an errno instead of silently ignoring
it.

Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c
index addc14af0c56..4326a690a509 100644
--- a/arch/x86_64/kernel/ptrace.c
+++ b/arch/x86_64/kernel/ptrace.c
@@ -536,8 +536,12 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                 }
                 ret = 0;
                 for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
-                        ret |= __get_user(tmp, (unsigned long __user *) data);
-                        putreg(child, ui, tmp);
+                        ret = __get_user(tmp, (unsigned long __user *) data);
+                        if (ret)
+                                break;
+                        ret = putreg(child, ui, tmp);
+                        if (ret)
+                                break;
                         data += sizeof(long);
                 }
                 break;