X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=lib%2Fvsprintf.c;fp=lib%2Fvsprintf.c;h=bdc4985b1ea71cc356bb165e8f70408aac10246e;hb=4d72ba014b4b0913f448ccaaaa2e8b39c54e3738;hp=8056dff6de642d2db005d185b60b64e29dd0d73a;hpb=1c7a8e622e84c9164dd665f5ad4879eac71bdc1e;p=cascardo%2Flinux.git

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 8056dff6de64..bdc4985b1ea7 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -389,6 +389,8 @@ struct printf_spec {
 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
 	signed int	precision:16;	/* # of digits/chars */
 } __packed;
+#define FIELD_WIDTH_MAX ((1 << 23) - 1)
+#define PRECISION_MAX ((1 << 15) - 1)
 
 static noinline_for_stack
 char *number(char *buf, char *end, unsigned long long num,
@@ -1845,6 +1847,24 @@ qualifier:
 	return ++fmt - start;
 }
 
+static void
+set_field_width(struct printf_spec *spec, int width)
+{
+	spec->field_width = width;
+	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
+		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
+	}
+}
+
+static void
+set_precision(struct printf_spec *spec, int prec)
+{
+	spec->precision = prec;
+	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
+		spec->precision = clamp(prec, 0, PRECISION_MAX);
+	}
+}
+
 /**
  * vsnprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
@@ -1912,11 +1932,11 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 		}
 
 		case FORMAT_TYPE_WIDTH:
-			spec.field_width = va_arg(args, int);
+			set_field_width(&spec, va_arg(args, int));
 			break;
 
 		case FORMAT_TYPE_PRECISION:
-			spec.precision = va_arg(args, int);
+			set_precision(&spec, va_arg(args, int));
 			break;
 
 		case FORMAT_TYPE_CHAR: {
@@ -2356,11 +2376,11 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 		}
 
 		case FORMAT_TYPE_WIDTH:
-			spec.field_width = get_arg(int);
+			set_field_width(&spec, get_arg(int));
 			break;
 
 		case FORMAT_TYPE_PRECISION:
-			spec.precision = get_arg(int);
+			set_precision(&spec, get_arg(int));
 			break;
 
 		case FORMAT_TYPE_CHAR: {