lib/vsprintf.c: fix potential NULL deref in hex_string

[cascardo/linux.git] / lib / vsprintf.c

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 3ab8c9c..4da1e7a 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -777,11 +777,19 @@ char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
        if (spec.field_width > 0)
                len = min_t(int, spec.field_width, 64);
 
-       for (i = 0; i < len && buf < end - 1; i++) {
-               buf = hex_byte_pack(buf, addr[i]);
+       for (i = 0; i < len; ++i) {
+               if (buf < end)
+                       *buf = hex_asc_hi(addr[i]);
+               ++buf;
+               if (buf < end)
+                       *buf = hex_asc_lo(addr[i]);
+               ++buf;
 
-               if (buf < end && separator && i != len - 1)
-                       *buf++ = separator;
+               if (separator && i != len - 1) {
+                       if (buf < end)
+                               *buf = separator;
+                       ++buf;
+               }
        }
 
        return buf;