From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750927AbcBEX1M (ORCPT ); Fri, 5 Feb 2016 18:27:12 -0500 Received: from mail-pa0-f42.google.com ([209.85.220.42]:33950 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750754AbcBEX1L (ORCPT ); Fri, 5 Feb 2016 18:27:11 -0500 From: Yang Shi To: aryabinin@virtuozzo.com, Will.Deacon@arm.com, Catalin.Marinas@arm.com Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org, yang.shi@linaro.org Subject: [PATCH] arm64: disable kasan when accessing frame->fp in unwind_frame Date: Fri, 5 Feb 2016 15:04:47 -0800 Message-Id: <1454713487-5239-1-git-send-email-yang.shi@linaro.org> X-Mailer: git-send-email 2.0.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When boot arm64 kernel with KASAN enabled, the below error is reported by kasan: BUG: KASAN: out-of-bounds in unwind_frame+0xec/0x260 at addr ffffffc064d57ba0 Read of size 8 by task pidof/499 page:ffffffbdc39355c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x0() page dumped because: kasan: bad access detected CPU: 2 PID: 499 Comm: pidof Not tainted 4.5.0-rc1 #119 Hardware name: Freescale Layerscape 2085a RDB Board (DT) Call trace: [] dump_backtrace+0x0/0x290 [] show_stack+0x24/0x30 [] dump_stack+0x8c/0xd8 [] kasan_report_error+0x558/0x588 [] kasan_report+0x60/0x70 [] __asan_load8+0x60/0x78 [] unwind_frame+0xec/0x260 [] get_wchan+0x110/0x160 [] do_task_stat+0xb44/0xb68 [] proc_tgid_stat+0x40/0x50 [] proc_single_show+0x88/0xd8 [] seq_read+0x370/0x770 [] __vfs_read+0xc8/0x1d8 [] vfs_read+0x94/0x168 [] SyS_read+0xb8/0x128 [] el0_svc_naked+0x24/0x28 Memory state around the buggy address: ffffffc064d57a80: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f4 f4 ffffffc064d57b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffffc064d57b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffffffc064d57c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc064d57c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Since the shadow byte pointed by the report is 0, so it may mean it is just hit oob in non-current task. So, disable the instrumentation here. Signed-off-by: Yang Shi --- arch/arm64/kernel/stacktrace.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index 4fad978..88278c2 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -64,7 +65,9 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) return -EINVAL; frame->sp = fp + 0x10; + kasan_disable_current(); frame->fp = *(unsigned long *)(fp); + kasan_enable_current(); frame->pc = *(unsigned long *)(fp + 8); #ifdef CONFIG_FUNCTION_GRAPH_TRACER -- 2.0.2