From: Xiaoming Ni <nixiaoming@huawei.com>
To: <penberg@cs.helsinki.fi>, <gregkh@linuxfoundation.org>,
<jslaby@suse.com>
Cc: <nico@fluxnic.net>, <textshell@uchuujin.de>, <sam@ravnborg.org>,
<daniel.vetter@ffwll.ch>, <mpatocka@redhat.com>,
<ghalat@redhat.com>, <linux-kernel@vger.kernel.org>,
<yangyingliang@huawei.com>, <yuehaibing@huawei.com>,
<zengweilin@huawei.com>
Subject: [PATCH] tty:vt: Add check the return value of kzalloc to avoid oops
Date: Thu, 19 Sep 2019 17:18:15 +0800 [thread overview]
Message-ID: <1568884695-56789-1-git-send-email-nixiaoming@huawei.com> (raw)
Using kzalloc() to allocate memory in function con_init(), but not
checking the return value, there is a risk of null pointer references
oops.
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
---
drivers/tty/vt/vt.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 34aa39d..db83e52 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -3357,15 +3357,33 @@ static int __init con_init(void)
for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
+ if (unlikely(!vc)) {
+ pr_warn("%s:failed to allocate memory for the %u vc\n",
+ __func__, currcons);
+ break;
+ }
INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
tty_port_init(&vc->port);
visual_init(vc, currcons, 1);
vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
+ if (unlikely(!vc->vc_screenbuf)) {
+ pr_warn("%s:failed to allocate memory for the %u vc_screenbuf\n",
+ __func__, currcons);
+ visual_deinit(vc);
+ tty_port_destroy(&vc->port);
+ kfree(vc);
+ vc_cons[currcons].d = NULL;
+ break;
+ }
vc_init(vc, vc->vc_rows, vc->vc_cols,
currcons || !vc->vc_sw->con_save_screen);
}
currcons = fg_console = 0;
master_display_fg = vc = vc_cons[currcons].d;
+ if (unlikely(!vc)) {
+ console_unlock();
+ return 0;
+ }
set_origin(vc);
save_screen(vc);
gotoxy(vc, vc->vc_x, vc->vc_y);
--
1.8.5.6
next reply other threads:[~2019-09-19 9:18 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-19 9:18 Xiaoming Ni [this message]
2019-09-19 9:29 ` [PATCH] tty:vt: Add check the return value of kzalloc to avoid oops Greg KH
2019-09-19 15:16 ` Mikulas Patocka
2019-09-20 2:29 ` Nixiaoming
2019-09-20 6:04 ` Greg KH
2019-09-20 2:56 ` Nicolas Pitre
2019-09-20 6:04 ` Greg KH
2019-09-21 7:26 ` Xiaoming Ni
2019-09-23 3:50 ` Nicolas Pitre
2019-09-25 8:37 ` Xiaoming Ni
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