From: Kees Cook <keescook@chromium.org>
Date: Fri, 3 Jun 2016 02:56:43 +0000 (-0700)
Subject: tile/ptrace: run seccomp after ptrace
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=635efc702984857b45a2a2491ed7a529e14cbdf9;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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@chromium.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
---

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]);