Re: [PATCH 0/2] configs/hardening: Some fixes for UBSAN

[Kees Cook <keescook@chromium.org>]

On Thu, Apr 11, 2024 at 11:11:05AM -0700, Nathan Chancellor wrote:
>   [    0.189542] Internal error: UBSAN: unrecognized failure code: 00000000f2005515 [#1] PREEMPT SMP

Oops! Yes, I didn't update the (arm64) trap handler to notice integer
overflows. I think I need something like:

diff --git a/lib/ubsan.c b/lib/ubsan.c
index 5fc107f61934..a2fb19f75825 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -77,6 +77,14 @@ const char *report_ubsan_failure(struct pt_regs *regs, u32 check_type)
 		return "UBSAN: alignment assumption";
 	case ubsan_type_mismatch:
 		return "UBSAN: type mismatch";
+#endif
+#ifdef CONFIG_UBSAN_SIGNED_INTEGER_WRAP
+	case ubsan_add_overflow:
+		return "UBSAN: integer addition overflow";
+	case ubsan_sub_overflow:
+		return "UBSAN: integer subtraction overflow";
+	case ubsan_mul_overflow:
+		return "UBSAN: integer multiplication overflow";
 #endif
 	default:
 		return "UBSAN: unrecognized failure code";

>   [    0.198326] Call trace:
>   [    0.198544]  cancel_delayed_work+0x54/0x94
>   [    0.198810]  deferred_probe_extend_timeout+0x20/0x6c
>   [    0.198988]  driver_register+0xa8/0x10c
>   [    0.199122]  __platform_driver_register+0x28/0x38
>   [    0.199258]  tegra194_cbb_init+0x24/0x34

Justin, does this trace match anything you found running syzkaller
against SIO? (I assume not -- this seems to be a tegra code path...)

-- 
Kees Cook