Re: [PATCH 6/7] lkdtm: crash on overwriting protected pmalloc var
From: J Freyensee <hidden>
Date: 2018-03-06 17:05:00
Also in:
linux-security-module, lkml
From: J Freyensee <hidden>
Date: 2018-03-06 17:05:00
Also in:
linux-security-module, lkml
+#ifdef CONFIG_PROTECTABLE_MEMORY
+void lkdtm_WRITE_RO_PMALLOC(void)
+{
+ struct gen_pool *pool;
+ int *i;
+
+ pool = pmalloc_create_pool("pool", 0);
+ if (unlikely(!pool)) {
+ pr_info("Failed preparing pool for pmalloc test.");
+ return;
+ }
+
+ i = (int *)pmalloc(pool, sizeof(int), GFP_KERNEL);
+ if (unlikely(!i)) {
+ pr_info("Failed allocating memory for pmalloc test.");
+ pmalloc_destroy_pool(pool);
+ return;
+ }
+
+ *i = INT_MAX;
+ pmalloc_protect_pool(pool);
+
+ pr_info("attempting bad pmalloc write at %p\n", i);
+ *i = 0;Seems harmless, but I don't get why *i local variable needs to be set to 0 at the end of this function. Otherwise, Reviewed-by: Jay Freyensee <redacted> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>