[AUDIT] Don't allow ptrace to fool auditing, log arch of audited syscalls.

We were calling ptrace_notify() after auditing the syscall and arguments,
but the debugger could have _changed_ them before the syscall was actually
invoked. Reorder the calls to fix that.

While we're touching ever call to audit_syscall_entry(), we also make it
take an extra argument: the architecture of the syscall which was made,
because some architectures allow more than one type of syscall.

Also add an explicit success/failure flag to audit_syscall_exit(), for
the benefit of architectures which return that in a condition register
rather than only returning a single register.

Change type of syscall return value to 'long' not 'int'.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 8 insertions, 5 deletions

diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c
index c7011675007..ecbccbbf5c2 100644
--- a/arch/x86_64/kernel/ptrace.c
+++ b/arch/x86_64/kernel/ptrace.c
@@ -629,25 +629,28 @@ static void syscall_trace(struct pt_regs *regs)
         }
 }
 
+#define audit_arch() (test_thread_flag(TIF_IA32) ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64)
+
 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
 {
         /* do the secure computing check first */
         secure_computing(regs->orig_rax);
 
+        if (test_thread_flag(TIF_SYSCALL_TRACE)
+            && (current->ptrace & PT_PTRACED))
+                syscall_trace(regs);
+
         if (unlikely(current->audit_context))
-                audit_syscall_entry(current, regs->orig_rax,
+                audit_syscall_entry(current, audit_arch(), regs->orig_rax,
                                     regs->rdi, regs->rsi,
                                     regs->rdx, regs->r10);
 
-        if (test_thread_flag(TIF_SYSCALL_TRACE)
-            && (current->ptrace & PT_PTRACED))
-                syscall_trace(regs);
 }
 
 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
 {
         if (unlikely(current->audit_context))
-                audit_syscall_exit(current, regs->rax);
+                audit_syscall_exit(current, AUDITSC_RESULT(regs->rax), regs->rax);
 
         if ((test_thread_flag(TIF_SYSCALL_TRACE)
              || test_thread_flag(TIF_SINGLESTEP))