s390/tty: Fix a potential memory leak bug

[ Upstream commit ad9bb8f049717d64c5e62b2a44954be9f681c65b ]

The check for get_zeroed_page() leads to a direct return
and overlooked the memory leak caused by loop allocation.
Add a free helper to free spaces allocated by get_zeroed_page().

Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20250218034104.2436469-1-haoxiang_li2024@163.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Haoxiang Li
2025-02-18 11:41:04 +08:00
committed by Greg Kroah-Hartman
parent 28e5a867aa
commit 7f30987294

View File

@@ -490,6 +490,17 @@ static const struct tty_operations sclp_ops = {
.flush_buffer = sclp_tty_flush_buffer,
};
/* Release allocated pages. */
static void __init __sclp_tty_free_pages(void)
{
struct list_head *page, *p;
list_for_each_safe(page, p, &sclp_tty_pages) {
list_del(page);
free_page((unsigned long)page);
}
}
static int __init
sclp_tty_init(void)
{
@@ -516,6 +527,7 @@ sclp_tty_init(void)
for (i = 0; i < MAX_KMEM_PAGES; i++) {
page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
if (page == NULL) {
__sclp_tty_free_pages();
tty_driver_kref_put(driver);
return -ENOMEM;
}