X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=mm%2Fmemory.c;h=4bfc3a9c3b182ef11728992f580a7591575cdfa6;hb=371a096edf43a8c71844cf71c20765c8b21d07d9;hp=f1a68049edfff60805e2c1019c4d950bfb3e5ed6;hpb=5e1b834b27fb2c27cde33a0752425f11d10c0b2d;p=cascardo%2Flinux.git

diff --git a/mm/memory.c b/mm/memory.c
index f1a68049edff..4bfc3a9c3b18 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3658,6 +3658,19 @@ int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
                         mem_cgroup_oom_synchronize(false);
 	}
 
+	/*
+	 * This mm has been already reaped by the oom reaper and so the
+	 * refault cannot be trusted in general. Anonymous refaults would
+	 * lose data and give a zero page instead e.g. This is especially
+	 * problem for use_mm() because regular tasks will just die and
+	 * the corrupted data will not be visible anywhere while kthread
+	 * will outlive the oom victim and potentially propagate the date
+	 * further.
+	 */
+	if (unlikely((current->flags & PF_KTHREAD) && !(ret & VM_FAULT_ERROR)
+				&& test_bit(MMF_UNSTABLE, &vma->vm_mm->flags)))
+		ret = VM_FAULT_SIGBUS;
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(handle_mm_fault);