[PATCH 10/14] parisc/ptrace: run seccomp after ptrace

From: Kees Cook
Date: Thu Jun 09 2016 - 17:06:02 EST


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

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: linux-parisc@xxxxxxxxxxxxxxx
---
arch/parisc/kernel/ptrace.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
index 8edc47c0b98e..e02d7b4d2b69 100644
--- a/arch/parisc/kernel/ptrace.c
+++ b/arch/parisc/kernel/ptrace.c
@@ -311,10 +311,6 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,

long do_syscall_trace_enter(struct pt_regs *regs)
{
- /* Do the secure computing check first. */
- if (secure_computing(NULL) == -1)
- return -1;
-
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
tracehook_report_syscall_entry(regs)) {
/*
@@ -325,6 +321,11 @@ long do_syscall_trace_enter(struct pt_regs *regs)
regs->gr[20] = -1UL;
goto out;
}
+
+ /* Do the secure computing check after ptrace. */
+ if (secure_computing(NULL) == -1)
+ return -1;
+
#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_enter(regs, regs->gr[20]);
--
2.7.4