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authorKees Cook <keescook@chromium.org>2016-06-02 12:16:31 -0700
committerGreg Hackmann <ghackmann@google.com>2018-11-27 21:12:05 +0000
commitd5ea505d8bc7339ec14bc3837dcfbdfaf3d68478 (patch)
tree8b5e44d6400b41350ba918255a30fd2040890b7c /arch
parent7f891268d5b80d4b9ee38be1a37cce5959bec00f (diff)
UPSTREAM: arm/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: Russell King <linux@armlinux.org.uk> Cc: linux-arm-kernel@lists.infradead.org (cherry picked from commit 0f3912fd934cdfd03d93f2dc6f064099795bf638) Bug: 119769499 Change-Id: Id82e4137207db42a8af31b2745581c53eaaf1f89 Signed-off-by: Greg Hackmann <ghackmann@google.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/kernel/ptrace.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index e6a538be2d88..ae738a6319f6 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))