Commit 0f3912fd authored by Kees Cook's avatar Kees Cook
Browse files

arm/ptrace: run seccomp after ptrace 



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

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
parent 93e35efb

arch/arm/kernel/ptrace.c

+6 −5
Original line number Diff line number Diff line
@@ -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))