Commit dc794e87 authored Oct 11, 2024 by Jeongjun Park Committed by Greg Kroah-Hartman Nov 08, 2024

vt: prevent kernel-infoleak in con_font_get()

commit f956052e00de211b5c9ebaa1958366c23f82ee9e upstream.

font.data may not initialize all memory spaces depending on the implementation
of vc->vc_sw->con_font_get. This may cause info-leak, so to prevent this, it
is safest to modify it to initialize the allocated memory space to 0, and it
generally does not affect the overall performance of the system.

Cc: stable@vger.kernel.org
Reported-by: <syzbot+955da2d57931604ee691@syzkaller.appspotmail.com>
Fixes: 05e2600cb0a4 ("VT: Bump font size limitation to 64x128 pixels")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Link: https://lore.kernel.org/r/20241010174619.59662-1-aha310510@gmail.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 7e948e45

drivers/tty/vt/vt.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -4519,7 +4519,7 @@ static int con_font_get(struct vc_data vc, struct console_font_op op)
	int c;		int c;

	if (op->data) {		if (op->data) {
	font.data = kmalloc(max_font_size, GFP_KERNEL);		font.data = kzalloc(max_font_size, GFP_KERNEL);
	if (!font.data)		if (!font.data)
	return -ENOMEM;		return -ENOMEM;
	} else		} else