s390/sclp: Add check for get_zeroed_page()

[ Upstream commit 3db42c75a921854a99db0a2775814fef97415bac ]

Add check for the return value of get_zeroed_page() in
sclp_console_init() to prevent null pointer dereference.
Furthermore, to solve the memory leak caused by the loop
allocation, add a free helper to do the free job.

Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20250218025216.2421548-1-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 10:52:16 +08:00
committed by Greg Kroah-Hartman
parent 96eab3c96a
commit 28e5a867aa

View File

@@ -263,6 +263,19 @@ static struct console sclp_console =
.index = 0 /* ttyS0 */ .index = 0 /* ttyS0 */
}; };
/*
* Release allocated pages.
*/
static void __init __sclp_console_free_pages(void)
{
struct list_head *page, *p;
list_for_each_safe(page, p, &sclp_con_pages) {
list_del(page);
free_page((unsigned long)page);
}
}
/* /*
* called by console_init() in drivers/char/tty_io.c at boot-time. * called by console_init() in drivers/char/tty_io.c at boot-time.
*/ */
@@ -282,6 +295,10 @@ sclp_console_init(void)
/* Allocate pages for output buffering */ /* Allocate pages for output buffering */
for (i = 0; i < sclp_console_pages; i++) { for (i = 0; i < sclp_console_pages; i++) {
page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
if (!page) {
__sclp_console_free_pages();
return -ENOMEM;
}
list_add_tail(page, &sclp_con_pages); list_add_tail(page, &sclp_con_pages);
} }
sclp_conbuf = NULL; sclp_conbuf = NULL;