[PATCH] lib/bitmap.c: return -EINVAL for grouping errors in __bitmap_parselist

[Pan Xinhui <xinhuix.pan@intel.com>]

Sometimes the input from user may cause an unexpected result.

just like __bitmap_parse, we return -EINVAL if there is no avaiable digit in each
parsing procedures.

Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com>
---
  lib/bitmap.c | 7 +++++--
  1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 64c0926..995fca2 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -504,7 +504,7 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
  		int nmaskbits)
  {
  	unsigned a, b;
-	int c, old_c, totaldigits;
+	int c, old_c, totaldigits, ndigits;
  	const char __user __force *ubuf = (const char __user __force *)buf;
  	int exp_digit, in_range;
  
@@ -514,6 +514,7 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
  		exp_digit = 1;
  		in_range = 0;
  		a = b = 0;
+		ndigits = 0;
  
  		/* Get the next cpu# or a range of cpu#'s */
  		while (buflen) {
@@ -555,8 +556,10 @@ static int __bitmap_parselist(const char *buf, unsigned int buflen,
  			if (!in_range)
  				a = b;
  			exp_digit = 0;
-			totaldigits++;
+			ndigits++; totaldigits++;
  		}
+		if (ndigits == 0)
+			return -EINVAL;
  		if (!(a <= b))
  			return -EINVAL;
  		if (b >= nmaskbits)
-- 
1.9.1