From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx48N9ChxObXVJgiqA+BwUAE+viRHoVO1gEfYhMjWgm1reLqzHJRnznCPAxutTE5A4ANaiB5n ARC-Seal: i=1; a=rsa-sha256; t=1523275470; cv=none; d=google.com; s=arc-20160816; b=jY/U+uuzyKduW3ZPenZRIHMqoTVS24Z/JM9aHS7g6xLUAh3q7IlaOzauPCuIl9QN1H wcZYffM02Ckurjedi5dPmnPAaNEJD+o0FPvHeAnkcwq7Daj0i+mTjaN+IFIFaP0TcVFW T/98/FaDLwGlT4iiG34JorY1PKd9+6aAvZqBj/DFQMRdJx0ZhULJuQaJ8eQNK26xPiI4 ttWbOHeuys92AbciFmNiLIVTuR86KaK0zbmx7opJj0C9qAZiOYeMyaihQ43hkMB8qrjz aaT/ckHNrx1H08kDz+cos03MzwphdezHoeOcRLEY3qDTmUrFCi4N5JtAc6IJcFRnyYKd JCDA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:delivered-to:list-id:list-subscribe:list-unsubscribe :list-help:list-post:precedence:mailing-list :arc-authentication-results; bh=zqw89oX0VDYEFbNnHUf8KMoRxXhoyIJsc7kMYSn54rA=; b=qc9Zq9QDpgR8H0j7UEbleC7AZLQnq7DqQ9ky2VdUptcEtt53kn5Qe+YbvBYHCAdRmn pzsVVQik8LzH5VfEpDVz1Gnn+MirdpqeOOpJtnRbAfMIZR4yIcuwuMttr88aPf/2W8kp ymVnd1AhtVvbVLrr0/lM4jlbZJ+7G9Nmw6l+zN3kFm1yqS1vxitDk+joImmcXXByb5C1 zzzj13Hel/TcjuUs35qpfTpVldmLSDTt91j/l+oNpMghYp6Ju+a1LN9jCW4jMsFo61k2 mFnIkEahZDo4I4Xu1wNuGTSJVtJhx8Zp4uKUhfxyx8OGriKbUyB20PRu3xy5JnbP4kFW 6WpQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=YxooVLzS; spf=pass (google.com: domain of kernel-hardening-return-12913-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12913-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=YxooVLzS; spf=pass (google.com: domain of kernel-hardening-return-12913-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12913-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: From: kpark3469@gmail.com To: kernel-hardening@lists.openwall.com Cc: catalin.marinas@arm.com, keescook@chromium.org, will.deacon@arm.com, mark.rutland@arm.com, james.morse@arm.com, panand@redhat.com, keun-o.park@darkmatter.ae, psodagud@codeaurora.org, jpoimboe@redhat.com, mingo@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/3] arm64: usercopy: implement arch_within_stack_frames Date: Mon, 9 Apr 2018 15:59:15 +0400 Message-Id: <1523275156-29087-3-git-send-email-kpark3469@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1523275156-29087-2-git-send-email-kpark3469@gmail.com> References: <1523275156-29087-1-git-send-email-kpark3469@gmail.com> <1523275156-29087-2-git-send-email-kpark3469@gmail.com> X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597247891648306653?= X-GMAIL-MSGID: =?utf-8?q?1597270100084034595?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: James Morse This implements arch_within_stack_frames() for arm64 that should validate if a given object is contained by a kernel stack frame. Signed-off-by: James Morse Reviewed-by: Sahara Reviewed-by: Kees Cook --- arch/arm64/Kconfig | 1 + arch/arm64/kernel/stacktrace.c | 76 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 177be0d..72d0747 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -128,6 +128,7 @@ config ARM64 select HAVE_SYSCALL_TRACEPOINTS select HAVE_KPROBES select HAVE_KRETPROBES + select HAVE_ARCH_WITHIN_STACK_FRAMES select IOMMU_DMA if IOMMU_SUPPORT select IRQ_DOMAIN select IRQ_FORCED_THREADING diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index d5718a0..5eb3784 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -27,6 +27,11 @@ #include #include +#define FAKE_FRAME(frame, my_func) do { \ + frame.fp = (unsigned long)__builtin_frame_address(0); \ + frame.pc = (unsigned long)my_func; \ +} while (0) + /* * AArch64 PCS assigns the frame pointer to x29. * @@ -100,6 +105,77 @@ void notrace walk_stackframe(struct task_struct *tsk, struct stackframe *frame, } } +struct check_frame_arg { + unsigned long obj_start; + unsigned long obj_end; + unsigned long frame_start; + int discard_frames; + int err; +}; + +static int check_frame(struct stackframe *frame, void *d) +{ + struct check_frame_arg *arg = d; + unsigned long frame_end = frame->fp; + + /* object overlaps multiple frames */ + if (arg->obj_start < frame->fp && frame->fp < arg->obj_end) { + arg->err = BAD_STACK; + return 1; + } + + /* + * Discard frames and check object is in a frame written early + * enough. + */ + if (arg->discard_frames) + arg->discard_frames--; + else if ((arg->frame_start <= arg->obj_start && + arg->obj_start < frame_end) && + (arg->frame_start < arg->obj_end && arg->obj_end <= frame_end)) + return 1; + + /* object exists in a previous frame */ + if (arg->obj_end < arg->frame_start) { + arg->err = BAD_STACK; + return 1; + } + + arg->frame_start = frame_end + 0x10; + + return 0; +} + +/* Check obj doesn't overlap a stack frame record */ +int arch_within_stack_frames(const void *stack, + const void *stack_end, + const void *obj, unsigned long obj_len) +{ + struct stackframe frame; + struct check_frame_arg arg; + + if (!IS_ENABLED(CONFIG_FRAME_POINTER)) + return NOT_STACK; + + arg.err = GOOD_FRAME; + arg.obj_start = (unsigned long)obj; + arg.obj_end = arg.obj_start + obj_len; + + FAKE_FRAME(frame, arch_within_stack_frames); + arg.frame_start = frame.fp; + + /* + * Skip 4 non-inlined frames: , + * arch_within_stack_frames(), check_stack_object() and + * __check_object_size(). + */ + arg.discard_frames = 4; + + walk_stackframe(current, &frame, check_frame, &arg); + + return arg.err; +} + #ifdef CONFIG_STACKTRACE struct stack_trace_data { struct stack_trace *trace; -- 2.7.4