test_kmod: fix bug which allows negative values on two config options

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

Link: http://lkml.kernel.org/r/[email protected]
Fixes: 39258f448d71 ("kmod: add test driver to stress test the module loader")
Signed-off-by: Luis R. Rodriguez <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Cc: Colin Ian King <[email protected]>
Cc: David Binderman <[email protected]>
Cc: Dmitry Torokhov <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Jessica Yu <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Michal Marek <[email protected]>
Cc: Miroslav Benes <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rusty Russell <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files 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;