From b7b7ac19fd9e2afbf5aea4db5e3f318576e6809f Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Tue, 26 Dec 2017 09:39:22 +0100
Subject: executor: check format strings

I see a crash which says:

	#0: too much cover 0 (errno 0)

while the code is:

	uint64_t n = ...;
	if (n >= kCoverSize)
		fail("#%d: too much cover %u", th->id, n);

It seems that the high part of n is set, but we don't see it.

Add printf format attribute to fail and friends and fix all similar cases.
Caught a bunch of similar cases and a missing argument in:

exitf("opendir(%s) failed due to NOFILE, exiting");
---
 pkg/csource/linux_common.go | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

(limited to 'pkg/csource/linux_common.go')

diff --git a/pkg/csource/linux_common.go b/pkg/csource/linux_common.go
index 1ec165b89..329c7e5e2 100644
--- a/pkg/csource/linux_common.go
+++ b/pkg/csource/linux_common.go
@@ -146,17 +146,19 @@ __attribute__((noreturn)) static void doexit(int status)
 #if defined(SYZ_EXECUTOR)
 #define exit vsnprintf
 #define _exit vsnprintf
-#endif
 
-#if defined(SYZ_EXECUTOR)
+#define uint64_t unsigned long long
+
 #if defined(__GNUC__)
 #define SYSCALLAPI
 #define NORETURN __attribute__((noreturn))
 #define ALIGNED(N) __attribute__((aligned(N)))
+#define PRINTF __attribute__((format(printf, 1, 2)))
 #else
 #define SYSCALLAPI WINAPI
 #define NORETURN __declspec(noreturn)
 #define ALIGNED(N) __declspec(align(N))
+#define PRINTF
 #endif
 
 typedef long(SYSCALLAPI* syscall_t)(long, long, long, long, long, long, long, long, long);
@@ -186,7 +188,7 @@ const int kErrorStatus = 68;
 #if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT)) ||            \
     defined(SYZ_USE_TMP_DIR) || defined(SYZ_TUN_ENABLE) || defined(SYZ_SANDBOX_NAMESPACE) || \
     defined(SYZ_SANDBOX_NONE) || defined(SYZ_SANDBOX_SETUID) || defined(__NR_syz_kvm_setup_cpu)
-NORETURN static void fail(const char* msg, ...)
+NORETURN PRINTF static void fail(const char* msg, ...)
 {
 	int e = errno;
 	va_list args;
@@ -199,7 +201,7 @@ NORETURN static void fail(const char* msg, ...)
 #endif
 
 #if defined(SYZ_EXECUTOR)
-NORETURN static void error(const char* msg, ...)
+NORETURN PRINTF static void error(const char* msg, ...)
 {
 	va_list args;
 	va_start(args, msg);
@@ -211,7 +213,7 @@ NORETURN static void error(const char* msg, ...)
 #endif
 
 #if defined(SYZ_EXECUTOR) || (defined(SYZ_REPEAT) && defined(SYZ_WAIT_REPEAT) && defined(SYZ_USE_TMP_DIR)) || defined(SYZ_FAULT_INJECTION)
-NORETURN static void exitf(const char* msg, ...)
+NORETURN PRINTF static void exitf(const char* msg, ...)
 {
 	int e = errno;
 	va_list args;
@@ -226,7 +228,7 @@ NORETURN static void exitf(const char* msg, ...)
 #if defined(SYZ_EXECUTOR) || defined(SYZ_DEBUG)
 static int flag_debug;
 
-static void debug(const char* msg, ...)
+PRINTF static void debug(const char* msg, ...)
 {
 	if (!flag_debug)
 		return;
@@ -296,10 +298,10 @@ static void segv_handler(int sig, siginfo_t* info, void* uctx)
 	const uintptr_t prog_start = 1 << 20;
 	const uintptr_t prog_end = 100 << 20;
 	if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) && (addr < prog_start || addr > prog_end)) {
-		debug("SIGSEGV on %p, skipping\n", addr);
+		debug("SIGSEGV on %p, skipping\n", (void*)addr);
 		_longjmp(segv_env, 1);
 	}
-	debug("SIGSEGV on %p, exiting\n", addr);
+	debug("SIGSEGV on %p, exiting\n", (void*)addr);
 	doexit(sig);
 }
 
@@ -1931,7 +1933,7 @@ retry:
 	dp = opendir(dir);
 	if (dp == NULL) {
 		if (errno == EMFILE) {
-			exitf("opendir(%s) failed due to NOFILE, exiting");
+			exitf("opendir(%s) failed due to NOFILE, exiting", dir);
 		}
 		exitf("opendir(%s) failed", dir);
 	}
-- 
cgit mrf-deployment