Commit b12045fb authored Oct 07, 2023 by Gui-Dong Han

ktask: add null-pointer checks for ktask_works in ktask_init()

BUAA inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I85XYM



-----------------------------------------------------

In ktask_init(), the pointer ktask_works
is allocated using kmalloc_array, which can fail and return NULL.
The pointer ktask_works is used in the following code:
list_add_tail(&ktask_works[i].kw_list, &ktask_free_works);
Thus, a null-pointer dereference can occur, crashing the kernel.
To fix this bug, the pointer ktask_works should be checked for NULL
after the call to kmalloc_array to avoid null-pointer dereference.

Signed-off-by: Gui-Dong Han <hanguidong@buaa.edu.cn>

parent 9afce123

kernel/ktask.c

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -572,6 +572,10 @@ void __init ktask_init(void)

	ktask_works = kmalloc_array(ktask_rlim_max, sizeof(struct ktask_work),		ktask_works = kmalloc_array(ktask_rlim_max, sizeof(struct ktask_work),
	GFP_KERNEL);		GFP_KERNEL);
			if (!ktask_works) {
			pr_warn("disabled (failed to alloc ktask_works)");
			goto out;
			}
	for (i = 0; i < ktask_rlim_max; ++i)		for (i = 0; i < ktask_rlim_max; ++i)
	list_add_tail(&ktask_works[i].kw_list, &ktask_free_works);		list_add_tail(&ktask_works[i].kw_list, &ktask_free_works);