From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x22f.google.com (mail-pf0-x22f.google.com [IPv6:2607:f8b0:400e:c00::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rQd6Z3N0KzDq62 for ; Fri, 10 Jun 2016 07:02:30 +1000 (AEST) Received: by mail-pf0-x22f.google.com with SMTP id c2so16363084pfa.2 for ; Thu, 09 Jun 2016 14:02:30 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Russell King , linux-arm-kernel@lists.infradead.org, Andy Lutomirski , Benjamin Herrenschmidt , Catalin Marinas , Chris Metcalf , Heiko Carstens , Helge Deller , "James E.J. Bottomley" , James Hogan , Jeff Dike , linux-arch@vger.kernel.org, linux-mips@linux-mips.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, "Maciej W. Rozycki" , Mark Rutland , Martin Schwidefsky , Michael Ellerman , Paul Mackerras , Ralf Baechle , Richard Weinberger , user-mode-linux-devel@lists.sourceforge.net, Will Deacon , x86@kernel.org Subject: [PATCH 07/14] arm/ptrace: run seccomp after ptrace Date: Thu, 9 Jun 2016 14:01:57 -0700 Message-Id: <1465506124-21866-8-git-send-email-keescook@chromium.org> In-Reply-To: <1465506124-21866-1-git-send-email-keescook@chromium.org> References: <1465506124-21866-1-git-send-email-keescook@chromium.org> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Close the hole where ptrace can change a syscall out from under seccomp. Signed-off-by: Kees Cook Cc: Russell King Cc: linux-arm-kernel@lists.infradead.org --- arch/arm/kernel/ptrace.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index ad5e90ab165c..dc7b372872ff 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -932,18 +932,19 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno) { current_thread_info()->syscall = scno; - /* Do the secure computing check first; failures should be fast. */ + if (test_thread_flag(TIF_SYSCALL_TRACE)) + tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER); + + /* Do seccomp after ptrace; syscall may have changed. */ #ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER if (secure_computing(NULL) == -1) return -1; #else /* XXX: remove this once OABI gets fixed */ - secure_computing_strict(scno); + secure_computing_strict(current_thread_info()->syscall); #endif - if (test_thread_flag(TIF_SYSCALL_TRACE)) - tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER); - + /* Tracer or seccomp may have changed syscall. */ scno = current_thread_info()->syscall; if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) -- 2.7.4