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Diffstat (limited to 'drivers/misc/lkdtm/bugs.c')
-rw-r--r--drivers/misc/lkdtm/bugs.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index de87693cf557..cc92bc3ed820 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -378,3 +378,39 @@ void lkdtm_DOUBLE_FAULT(void)
pr_err("XFAIL: this test is ia32-only\n");
#endif
}
+
+#ifdef CONFIG_ARM64_PTR_AUTH
+static noinline void change_pac_parameters(void)
+{
+ /* Reset the keys of current task */
+ ptrauth_thread_init_kernel(current);
+ ptrauth_thread_switch_kernel(current);
+}
+
+#define CORRUPT_PAC_ITERATE 10
+noinline void lkdtm_CORRUPT_PAC(void)
+{
+ int i;
+
+ if (!system_supports_address_auth()) {
+ pr_err("FAIL: arm64 pointer authentication feature not present\n");
+ return;
+ }
+
+ pr_info("Change the PAC parameters to force function return failure\n");
+ /*
+ * Pac is a hash value computed from input keys, return address and
+ * stack pointer. As pac has fewer bits so there is a chance of
+ * collision, so iterate few times to reduce the collision probability.
+ */
+ for (i = 0; i < CORRUPT_PAC_ITERATE; i++)
+ change_pac_parameters();
+
+ pr_err("FAIL: %s test failed. Kernel may be unstable from here\n", __func__);
+}
+#else /* !CONFIG_ARM64_PTR_AUTH */
+noinline void lkdtm_CORRUPT_PAC(void)
+{
+ pr_err("FAIL: arm64 pointer authentication config disabled\n");
+}
+#endif