[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>

8 files changed, 139 insertions, 58 deletions

diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c
index b2f17640ce..5606ec7a5c 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);
+
 }
diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c
index 55789fcd72..8dde0b16d4 100644
--- a/arch/ia64/kernel/ptrace.c
+++ b/arch/ia64/kernel/ptrace.c
@@ -1595,20 +1595,25 @@ syscall_trace_enter (long arg0, long arg1, long arg2, long arg3,
                      long arg4, long arg5, long arg6, long arg7,
                      struct pt_regs regs)
 {
-        long syscall;
+        if (test_thread_flag(TIF_SYSCALL_TRACE) 
+            && (current->ptrace & PT_PTRACED))
+                syscall_trace();
 
         if (unlikely(current->audit_context)) {
-                if (IS_IA32_PROCESS(&regs))
+                long syscall;
+                int arch;
+
+                if (IS_IA32_PROCESS(&regs)) {
                         syscall = regs.r1;
-                else
+                        arch = AUDIT_ARCH_I386;
+                } else {
                         syscall = regs.r15;
+                        arch = AUDIT_ARCH_IA64;
+                }
 
-                audit_syscall_entry(current, syscall, arg0, arg1, arg2, arg3);
+                audit_syscall_entry(current, arch, syscall, arg0, arg1, arg2, arg3);
         }
 
-        if (test_thread_flag(TIF_SYSCALL_TRACE)
-            && (current->ptrace & PT_PTRACED))
-                syscall_trace();
 }
 
 /* "asmlinkage" so the input arguments are preserved... */
@@ -1619,7 +1624,7 @@ syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
                      struct pt_regs regs)
 {
         if (unlikely(current->audit_context))
-                audit_syscall_exit(current, regs.r8);
+                audit_syscall_exit(current, AUDITSC_RESULT(regs.r10), regs.r8);
 
         if (test_thread_flag(TIF_SYSCALL_TRACE)
             && (current->ptrace & PT_PTRACED))
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 92f2c39afe..eaf7be9d0b 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -300,25 +300,38 @@ out:
         return ret;
 }
 
+static inline int audit_arch()
+{
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+#ifdef CONFIG_MIPS64
+        if (!(current->thread.mflags & MF_32BIT_REGS))
+                return AUDIT_ARCH_MIPSEL64;
+#endif /* MIPS64 */
+        return AUDIT_ARCH_MIPSEL;
+
+#else /* big endian... */
+#ifdef CONFIG_MIPS64
+        if (!(current->thread.mflags & MF_32BIT_REGS))
+                return AUDIT_ARCH_MIPS64;
+#endif /* MIPS64 */
+        return AUDIT_ARCH_MIPS;
+
+#endif /* endian */
+}
+
 /*
  * Notification of system call entry/exit
  * - triggered by current->work.syscall_trace
  */
 asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
 {
-        if (unlikely(current->audit_context)) {
-                if (!entryexit)
-                        audit_syscall_entry(current, regs->regs[2],
-                                            regs->regs[4], regs->regs[5],
-                                            regs->regs[6], regs->regs[7]);
-                else
-                        audit_syscall_exit(current, regs->regs[2]);
-        }
+        if (unlikely(current->audit_context) && entryexit)
+                audit_syscall_exit(current, AUDITSC_RESULT(regs->regs[2]), regs->regs[2]);
 
         if (!test_thread_flag(TIF_SYSCALL_TRACE))
-                return;
+                goto out;
         if (!(current->ptrace & PT_PTRACED))
-                return;
+                goto out;
 
         /* The 0x80 provides a way for the tracing parent to distinguish
            between a syscall stop and SIGTRAP delivery */
@@ -334,4 +347,9 @@ asmlinkage 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(), regs->regs[2],
+                                    regs->regs[4], regs->regs[5],
+                                    regs->regs[6], regs->regs[7]);
 }
diff --git a/arch/ppc64/kernel/ptrace.c b/arch/ppc64/kernel/ptrace.c
index 354a287c67..3c76333ec3 100644
--- a/arch/ppc64/kernel/ptrace.c
+++ b/arch/ppc64/kernel/ptrace.c
@@ -304,14 +304,17 @@ static void do_syscall_trace(void)
 
 void do_syscall_trace_enter(struct pt_regs *regs)
 {
+        if (test_thread_flag(TIF_SYSCALL_TRACE)
+            && (current->ptrace & PT_PTRACED))
+                do_syscall_trace();
+
         if (unlikely(current->audit_context))
-                audit_syscall_entry(current, regs->gpr[0],
+                audit_syscall_entry(current,
+                                    test_thread_flag(TIF_32BIT)?AUDIT_ARCH_PPC:AUDIT_ARCH_PPC64,
+                                    regs->gpr[0],
                                     regs->gpr[3], regs->gpr[4],
                                     regs->gpr[5], regs->gpr[6]);
 
-        if (test_thread_flag(TIF_SYSCALL_TRACE)
-            && (current->ptrace & PT_PTRACED))
-                do_syscall_trace();
 }
 
 void do_syscall_trace_leave(struct pt_regs *regs)
@@ -319,7 +322,9 @@ void do_syscall_trace_leave(struct pt_regs *regs)
         secure_computing(regs->gpr[0]);