regulator: core: replace sprintf with scnprintf

In order to avoid potential overflows in print_constraints we
better replace sprintf() with scnprintf().

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 6b9edb5..9da5c55 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -780,58 +780,63 @@ static void print_constraints(struct regulator_dev *rdev)
 {
        struct regulation_constraints *constraints = rdev->constraints;
        char buf[160] = "";
+       size_t len = sizeof(buf) - 1;
        int count = 0;
        int ret;
 
        if (constraints->min_uV && constraints->max_uV) {
                if (constraints->min_uV == constraints->max_uV)
-                       count += sprintf(buf + count, "%d mV ",
-                                        constraints->min_uV / 1000);
+                       count += scnprintf(buf + count, len - count, "%d mV ",
+                                          constraints->min_uV / 1000);
                else
-                       count += sprintf(buf + count, "%d <--> %d mV ",
-                                        constraints->min_uV / 1000,
-                                        constraints->max_uV / 1000);
+                       count += scnprintf(buf + count, len - count,
+                                          "%d <--> %d mV ",
+                                          constraints->min_uV / 1000,
+                                          constraints->max_uV / 1000);
        }
 
        if (!constraints->min_uV ||
            constraints->min_uV != constraints->max_uV) {
                ret = _regulator_get_voltage(rdev);
                if (ret > 0)
-                       count += sprintf(buf + count, "at %d mV ", ret / 1000);
+                       count += scnprintf(buf + count, len - count,
+                                          "at %d mV ", ret / 1000);
        }
 
        if (constraints->uV_offset)
-               count += sprintf(buf + count, "%dmV offset ",
-                                constraints->uV_offset / 1000);
+               count += scnprintf(buf + count, len - count, "%dmV offset ",
+                                  constraints->uV_offset / 1000);
 
        if (constraints->min_uA && constraints->max_uA) {
                if (constraints->min_uA == constraints->max_uA)
-                       count += sprintf(buf + count, "%d mA ",
-                                        constraints->min_uA / 1000);
+                       count += scnprintf(buf + count, len - count, "%d mA ",
+                                          constraints->min_uA / 1000);
                else
-                       count += sprintf(buf + count, "%d <--> %d mA ",
-                                        constraints->min_uA / 1000,
-                                        constraints->max_uA / 1000);
+                       count += scnprintf(buf + count, len - count,
+                                          "%d <--> %d mA ",
+                                          constraints->min_uA / 1000,
+                                          constraints->max_uA / 1000);
        }
 
        if (!constraints->min_uA ||
            constraints->min_uA != constraints->max_uA) {
                ret = _regulator_get_current_limit(rdev);
                if (ret > 0)
-                       count += sprintf(buf + count, "at %d mA ", ret / 1000);
+                       count += scnprintf(buf + count, len - count,
+                                          "at %d mA ", ret / 1000);
        }
 
        if (constraints->valid_modes_mask & REGULATOR_MODE_FAST)
-               count += sprintf(buf + count, "fast ");
+               count += scnprintf(buf + count, len - count, "fast ");
        if (constraints->valid_modes_mask & REGULATOR_MODE_NORMAL)
-               count += sprintf(buf + count, "normal ");
+               count += scnprintf(buf + count, len - count, "normal ");
        if (constraints->valid_modes_mask & REGULATOR_MODE_IDLE)
-               count += sprintf(buf + count, "idle ");
+               count += scnprintf(buf + count, len - count, "idle ");
        if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
-               count += sprintf(buf + count, "standby");
+               count += scnprintf(buf + count, len - count, "standby");
 
        if (!count)
-               sprintf(buf, "no parameters");
+               scnprintf(buf, len, "no parameters");
 
        rdev_dbg(rdev, "%s\n", buf);