Close the hole where ptrace can change a syscall out from under seccomp.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
asmlinkage int syscall_trace_enter(struct pt_regs *regs)
{
- /* Do the secure computing check first; failures should be fast. */
- if (secure_computing(NULL) == -1)
- return -1;
-
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
+ /* Do the secure computing after ptrace; failures should be fast. */
+ if (secure_computing(NULL) == -1)
+ return -1;
+
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, regs->syscallno);