lkdtm/bugs: Check for the NULL pointer after calling kmalloc

[ Upstream commit 4a9800c81d ]

As the possible failure of the kmalloc(), the not_checked and checked
could be NULL pointer.
Therefore, it should be better to check it in order to avoid the
dereference of the NULL pointer.
Also, we need to kfree the 'not_checked' and 'checked' to avoid
the memory leak if fails.
And since it is just a test, it may directly return without error
number.

Fixes: ae2e1aad3e ("drivers/misc/lkdtm/bugs.c: add arithmetic overflow and array bounds checks")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220120092936.1874264-1-jiasheng@iscas.ac.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jiasheng Jiang 2022-01-20 17:29:36 +08:00 committed by Greg Kroah-Hartman
parent adc0270023
commit ce12f7f6b1

View file

@ -327,6 +327,11 @@ void lkdtm_ARRAY_BOUNDS(void)
not_checked = kmalloc(sizeof(*not_checked) * 2, GFP_KERNEL);
checked = kmalloc(sizeof(*checked) * 2, GFP_KERNEL);
if (!not_checked || !checked) {
kfree(not_checked);
kfree(checked);
return;
}
pr_info("Array access within bounds ...\n");
/* For both, touch all bytes in the actual member size. */