From nobody Wed Apr 15 04:33:12 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1E1D2C19F21 for ; Wed, 27 Jul 2022 03:23:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240192AbiG0DXt (ORCPT ); Tue, 26 Jul 2022 23:23:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231315AbiG0DXq (ORCPT ); Tue, 26 Jul 2022 23:23:46 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9D222FA; Tue, 26 Jul 2022 20:23:44 -0700 (PDT) Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Lszc901VYz9ssr; Wed, 27 Jul 2022 11:22:33 +0800 (CST) Received: from dggpemm500013.china.huawei.com (7.185.36.172) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 27 Jul 2022 11:23:42 +0800 Received: from ubuntu1804.huawei.com (10.67.175.36) by dggpemm500013.china.huawei.com (7.185.36.172) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 27 Jul 2022 11:23:42 +0800 From: Chen Zhongjin To: , , CC: , , , , Subject: [PATCH] kprobes: Forbid probing on kprobe_insn_slot Date: Wed, 27 Jul 2022 11:20:58 +0800 Message-ID: <20220727032058.60444-1-chenzhongjin@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.67.175.36] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500013.china.huawei.com (7.185.36.172) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Syzkaller reported a BUG on arm64: Unrecoverable kprobe detected. Dumping kprobe: Name: (null) Offset: 0 Address: 0xffffa00010019000 ------------[ cut here ]------------ kernel BUG at arch/arm64/kernel/probes/kprobes.c:235! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: CPU: 1 PID: 31060 Comm: syz-executor.6 Not tainted 5.10.0 #11 ... Call trace: =C2=A0reenter_kprobe arch/arm64/kernel/probes/kprobes.c:234 [inline] =C2=A0kprobe_handler+0x23c/0x26c arch/arm64/kernel/probes/kprobes.c:339 =C2=A0kprobe_breakpoint_handler+0x24/0x34 arch/arm64/kernel/probes/kprobes.= c:406 =C2=A0call_break_hook+0xf4/0x13c arch/arm64/kernel/debug-monitors.c:322 =C2=A0brk_handler+0x2c/0xa0 arch/arm64/kernel/debug-monitors.c:329 =C2=A0do_debug_exception+0x140/0x230 arch/arm64/mm/fault.c:867 =C2=A0el1_dbg+0x38/0x50 arch/arm64/kernel/entry-common.c:182 =C2=A0el1_sync_handler+0xf4/0x150 arch/arm64/kernel/entry-common.c:219 =C2=A0el1_sync+0x74/0x100 arch/arm64/kernel/entry.S:665 =C2=A00xffffa00010019000 =C2=A0do_futex+0x2f4/0x370 kernel/futex.c:3735 =C2=A0__do_sys_futex kernel/futex.c:3798 [inline] =C2=A0__se_sys_futex kernel/futex.c:3764 [inline] =C2=A0__arm64_sys_futex+0x168/0x3a0 kernel/futex.c:3764 =C2=A0__invoke_syscall arch/arm64/kernel/syscall.c:36 [inline] =C2=A0invoke_syscall arch/arm64/kernel/syscall.c:48 [inline] =C2=A0el0_svc_common.constprop.0+0xf4/0x414 arch/arm64/kernel/syscall.c:155 =C2=A0do_el0_svc+0x50/0x11c arch/arm64/kernel/syscall.c:217 =C2=A0el0_svc+0x20/0x30 arch/arm64/kernel/entry-common.c:353 =C2=A0el0_sync_handler+0xe4/0x1e0 arch/arm64/kernel/entry-common.c:369 =C2=A0el0_sync+0x148/0x180 arch/arm64/kernel/entry.S:683 Code: 91018360 97ff1838 aa1703e0 97ff1fdf (d4210000) ---[ end trace 767503e946e01b15 ]--- Syzbot tried to porbe on a kprobe_insn_slot. kprobe will replace instruciton with a break and store the origin one on kprobe_insn_slot. However these slots are not in .kprobes.text and exported by perf_event_ksymbol so can be probed by perf interface. Probing these slots will triggers kprobe handler inside single step process and for some architectures such as arm64 this will causes a bug(). These slots are kprobe process so they should not be probed anyway. Add kprobe_insn_slot check when register_kprobe to forbid probing on these slots. Signed-off-by: Chen Zhongjin --- kernel/kprobes.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index f214f8c088ed..3e798b62db70 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1562,6 +1562,8 @@ static int check_kprobe_address_safe(struct kprobe *p, /* Ensure it is not in reserved area nor out of text */ if (!kernel_text_address((unsigned long) p->addr) || within_kprobe_blacklist((unsigned long) p->addr) || + is_kprobe_insn_slot((unsigned long) p->addr) || + is_kprobe_optinsn_slot((unsigned long) p->addr) || jump_label_text_reserved(p->addr, p->addr) || static_call_text_reserved(p->addr, p->addr) || find_bug((unsigned long)p->addr)) { --=20 2.17.1