linux-kernel - [PATCH 13/14] tile/ptrace: run seccomp after ptrace

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1465506124-21866-14-git-send-email-keescook@chromium.org>
Date:	Thu,  9 Jun 2016 14:02:03 -0700
From:	Kees Cook <keescook@...omium.org>
To:	linux-kernel@...r.kernel.org
Cc:	Kees Cook <keescook@...omium.org>,
	Chris Metcalf <cmetcalf@...lanox.com>,
	Andy Lutomirski <luto@...nel.org>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Catalin Marinas <catalin.marinas@....com>,
	Heiko Carstens <heiko.carstens@...ibm.com>,
	Helge Deller <deller@....de>,
	"James E.J. Bottomley" <jejb@...isc-linux.org>,
	James Hogan <james.hogan@...tec.com>,
	Jeff Dike <jdike@...toit.com>, linux-arch@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-mips@...ux-mips.org,
	linux-parisc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
	linux-s390@...r.kernel.org, "Maciej W. Rozycki" <macro@...tec.com>,
	Mark Rutland <mark.rutland@....com>,
	Martin Schwidefsky <schwidefsky@...ibm.com>,
	Michael Ellerman <mpe@...erman.id.au>,
	Paul Mackerras <paulus@...ba.org>,
	Ralf Baechle <ralf@...ux-mips.org>,
	Richard Weinberger <richard@....at>,
	Russell King <linux@...linux.org.uk>,
	user-mode-linux-devel@...ts.sourceforge.net,
	Will Deacon <will.deacon@....com>, x86@...nel.org
Subject: [PATCH 13/14] tile/ptrace: run seccomp after ptrace

Close the hole where ptrace can change a syscall out from under seccomp.

Signed-off-by: Kees Cook <keescook@...omium.org>
Cc: Chris Metcalf <cmetcalf@...lanox.com>
---
 arch/tile/kernel/ptrace.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c
index 8c6d2f2fefa3..d89b7011667c 100644
--- a/arch/tile/kernel/ptrace.c
+++ b/arch/tile/kernel/ptrace.c
@@ -255,14 +255,15 @@ int do_syscall_trace_enter(struct pt_regs *regs)
 {
 	u32 work = ACCESS_ONCE(current_thread_info()->flags);
 
-	if (secure_computing(NULL) == -1)
+	if ((work & _TIF_SYSCALL_TRACE) &&
+	    tracehook_report_syscall_entry(regs)) {
+		regs->regs[TREG_SYSCALL_NR] = -1;
 		return -1;
-
-	if (work & _TIF_SYSCALL_TRACE) {
-		if (tracehook_report_syscall_entry(regs))
-			regs->regs[TREG_SYSCALL_NR] = -1;
 	}
 
+	if (secure_computing(NULL) == -1)
+		return -1;
+
 	if (work & _TIF_SYSCALL_TRACEPOINT)
 		trace_sys_enter(regs, regs->regs[TREG_SYSCALL_NR]);
 
-- 
2.7.4