[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, 9 insertions, 10 deletions

diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c
index b2f17640ceff..5606ec7a5c2b 100644
--- a/arch/i386/kernel/ptrace.c
+++ b/arch/i386/kernel/ptrace.c
@@ -682,24 +682,18 @@ void do_syscall_trace(struct pt_regs *regs, int entryexit)
         /* do the secure computing check first */
         secure_computing(regs->orig_eax);
 
-        if (unlikely(current->audit_context)) {
-                if (!entryexit)
-                        audit_syscall_entry(current, regs->orig_eax,
-                                            regs->ebx, regs->ecx,
-                                            regs->edx, regs->esi);
-                else
-                        audit_syscall_exit(current, regs->eax);
-        }
+        if (unlikely(current->audit_context) && entryexit)
+                audit_syscall_exit(current, AUDITSC_RESULT(regs->eax), regs->eax);
 
         if (!(current->ptrace & PT_PTRACED))
-                return;
+                goto out;
 
         /* Fake a debug trap */
         if (test_thread_flag(TIF_SINGLESTEP))
                 send_sigtrap(current, regs, 0);
 
         if (!test_thread_flag(TIF_SYSCALL_TRACE))
-                return;
+                goto out;
 
         /* the 0x80 provides a way for the tracing parent to distinguish
            between a syscall stop and SIGTRAP delivery */
@@ -714,4 +708,9 @@ void do_syscall_trace(struct pt_regs *regs, int entryexit)
                 send_sig(current->exit_code, current, 1);
                 current->exit_code = 0;
         }
+ out:
+        if (unlikely(current->audit_context) && !entryexit)
+                audit_syscall_entry(current, AUDIT_ARCH_I386, regs->orig_eax,
+                                    regs->ebx, regs->ecx, regs->edx, regs->esi);
+
 }