From: Yangxi Xiang <xyangxi5@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
Johan Hovold <johan@kernel.org>,
Igor Matheus Andrade Torrente <igormtorrente@gmail.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
nick black <dankamongmen@gmail.com>,
Yangxi Xiang <xyangxi5@gmail.com>
Subject: [PATCH] vt: fix memory overlapping when deleting chars in the buffer
Date: Mon, 27 Jun 2022 18:29:40 +0800 [thread overview]
Message-ID: <20220627102940.23232-1-xyangxi5@gmail.com> (raw)
A memory overlapping copy occurs when deleting a long line. Fix it by
using scr_memmovew.
Signed-off-by: Yangxi Xiang <xyangxi5@gmail.com>
---
drivers/tty/vt/vt.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index f8c87c4d7399..d87bff9d8ed5 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -853,9 +853,13 @@ static void insert_char(struct vc_data *vc, unsigned int nr)
static void delete_char(struct vc_data *vc, unsigned int nr)
{
unsigned short *p = (unsigned short *) vc->vc_pos;
+ unsigned short cp = (vc->vc_cols - vc->state.x - nr) * 2;
vc_uniscr_delete(vc, nr);
- scr_memcpyw(p, p + nr, (vc->vc_cols - vc->state.x - nr) * 2);
+ if (cp > nr)
+ scr_memmovew(p, p + nr, cp);
+ else
+ scr_memcpyw(p, p + nr, cp);
scr_memsetw(p + vc->vc_cols - vc->state.x - nr, vc->vc_video_erase_char,
nr * 2);
vc->vc_need_wrap = 0;
--
2.17.1
next reply other threads:[~2022-06-27 10:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-27 10:29 Yangxi Xiang [this message]
2022-06-27 10:47 ` [PATCH] vt: fix memory overlapping when deleting chars in the buffer Greg Kroah-Hartman
2022-06-27 11:04 ` Yangxi Xiang
2022-06-27 11:07 ` Greg Kroah-Hartman
2022-06-27 11:40 ` Yangxi Xiang
2022-06-27 12:29 ` Greg Kroah-Hartman
-- strict thread matches above, loose matches on Subject: below --
2022-06-28 8:08 [PATCH v2] " Jiri Slaby
2022-06-28 8:27 ` [PATCH] " Yangxi Xiang
2022-06-28 8:38 ` Jiri Slaby
2022-06-28 8:59 ` Yangxi Xiang
2022-06-28 9:11 ` Greg Kroah-Hartman
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