[PATCH 3/5] test_kmod: fix bug which allows negative values on two config options

From: Luis R. Rodriguez
Date: Wed Aug 02 2017 - 17:15:29 EST


Parsing with kstrtol() enables values to be negative, and we failed
to check for negative values when parsing with either
test_dev_config_update_uint_sync() or
test_dev_config_update_uint_range().

test_dev_config_update_uint_range() has a minimum check though so an
issue is not present there. test_dev_config_update_uint_sync() is only
used for the number of threads to use (config_num_threads_store()),
and indeed this would fail with an attempt for a large allocation.

Although the issue is only present in practice with the first fix
both by using kstrtoul() instead of kstrtol().

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Fixes: 39258f448d71 ("kmod: add test driver to stress test the module loader")
Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
---
lib/test_kmod.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/test_kmod.c b/lib/test_kmod.c
index 90c91541fc16..8fc0a7a19c83 100644
--- a/lib/test_kmod.c
+++ b/lib/test_kmod.c
@@ -880,10 +880,10 @@ static int test_dev_config_update_uint_sync(struct kmod_test_device *test_dev,
int (*test_sync)(struct kmod_test_device *test_dev))
{
int ret;
- long new;
+ unsigned long new;
unsigned int old_val;

- ret = kstrtol(buf, 10, &new);
+ ret = kstrtoul(buf, 10, &new);
if (ret)
return ret;

@@ -918,9 +918,9 @@ static int test_dev_config_update_uint_range(struct kmod_test_device *test_dev,
unsigned int max)
{
int ret;
- long new;
+ unsigned long new;

- ret = kstrtol(buf, 10, &new);
+ ret = kstrtoul(buf, 10, &new);
if (ret)
return ret;

--
2.11.0