From: Jiasheng Jiang jiasheng@iscas.ac.cn
[ Upstream commit 4a9800c81d2f34afb66b4b42e0330ae8298019a2 ]
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: ae2e1aad3e48 ("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 --- drivers/misc/lkdtm/bugs.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index f21854ac5cc2..4f2808b2ca3c 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -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. */