[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>

6 files changed, 79 insertions, 48 deletions

diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c
index b2f17640cef..5606ec7a5c2 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 55789fcd721..8dde0b16d4c 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 92f2c39afe2..eaf7be9d0b0 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 354a287c67e..3c76333ec3a 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]);
 
 	if (unlikely(current->audit_context))
-		audit_syscall_exit(current, regs->result);
+		audit_syscall_exit(current, 
+				   (regs->ccr&0x1000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
+				   regs->result);
 
 	if ((test_thread_flag(TIF_SYSCALL_TRACE)
 	     || test_thread_flag(TIF_SINGLESTEP))
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 647233c02fc..2d546c67f7c 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -711,18 +711,13 @@ out:
 asmlinkage void
 syscall_trace(struct pt_regs *regs, int entryexit)
 {
-	if (unlikely(current->audit_context)) {
-		if (!entryexit)
-			audit_syscall_entry(current, regs->gprs[2],
-					    regs->orig_gpr2, regs->gprs[3],
-					    regs->gprs[4], regs->gprs[5]);
-		else
-			audit_syscall_exit(current, regs->gprs[2]);
-	}
+	if (unlikely(current->audit_context) && entryexit)
+		audit_syscall_exit(current, AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]);
+
 	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		return;
+		goto out;
 	if (!(current->ptrace & PT_PTRACED))
-		return;
+		goto out;
 	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 				 ? 0x80 : 0));
 
@@ -735,4 +730,10 @@ 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, 
+				    test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X,
+				    regs->gprs[2], regs->orig_gpr2, regs->gprs[3],
+				    regs->gprs[4], regs->gprs[5]);
 }
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))