From 56dd308d7457bac5c0a0707caaaac3ad64e39925 Mon Sep 17 00:00:00 2001
From: GustavoLCR <gugulcr@gmail.com>
Date: Fri, 11 Jan 2019 03:20:14 -0300
Subject: [PATCH] Fix segfault and add warning

---
 libr/bin/bin.c  | 4 ++++
 libr/util/buf.c | 5 ++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/libr/bin/bin.c b/libr/bin/bin.c
index 4ae5744c77..01936f575d 100644
--- a/libr/bin/bin.c
+++ b/libr/bin/bin.c
@@ -1232,6 +1232,10 @@ R_API RBuffer *r_bin_package(RBin *bin, const char *type, const char *file, RLis
 		ut32 num;
 		ut8 *num8 = (ut8*)&num;
 		RBuffer *buf = r_buf_new_file (file, true);
+		if (!buf) {
+			eprintf ("Cannot open file %s - Permission Denied.\n", file);
+			return NULL;
+		}
 		r_buf_write_at (buf, 0, (const ut8*)"\xca\xfe\xba\xbe", 4);
 		int count = r_list_length (files);
 
diff --git a/libr/util/buf.c b/libr/util/buf.c
index 6df6212ea7..10ea6afcda 100644
--- a/libr/util/buf.c
+++ b/libr/util/buf.c
@@ -786,10 +786,9 @@ R_API int r_buf_fread_at (RBuffer *b, ut64 addr, ut8 *buf, const char *fmt, int
 
 //ret 0 or -1 if failed; ret copied length if success
 R_API int r_buf_write_at(RBuffer *b, ut64 addr, const ut8 *buf, int len) {
+	r_return_val_if_fail (b && buf && len > 0, 0);
+
 	RIOBind *iob = b->iob;
-	if (!b || !buf || len < 1) {
-		return 0;
-	}
 	ut64 start = addr - b->base + b->offset;
 	ut64 effective_size = r_buf_size (b);
 	int real_len = len;