From e503e9218c460ea05587c44c0bba2131562d1e36 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Sun, 24 Feb 2013 20:06:09 -0500 Subject: [PATCH] tty vt: fix character insertion overflow MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit a883b70d8e0a88278c0a1f80753b4dc99962b541 upstream. Commit 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition") broke insert_char() in multiple ways. Then commit b1a925f44a3a ("tty vt: Fix a regression in command line edition") partially fixed it. However, the buffer being moved is still too large and overflowing beyond the end of the current line, corrupting existing characters on the next line. Example test case: echo -e "abc\nde\x1b[A\x1b[4h \x1b[4l\x1b[B" Expected result: ab c de Current result: ab c e Needless to say that this is very annoying when inserting words in the middle of paragraphs with certain text editors. Signed-off-by: Nicolas Pitre Acked-by: Jean-François Moine Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/vt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 8fd8968..3614c9c 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -539,7 +539,7 @@ static void insert_char(struct vc_data *vc, unsigned int nr) { unsigned short *p = (unsigned short *) vc->vc_pos; - scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x) * 2); + scr_memmovew(p + nr, p, (vc->vc_cols - vc->vc_x - nr) * 2); scr_memsetw(p, vc->vc_video_erase_char, nr * 2); vc->vc_need_wrap = 0; if (DO_UPDATE(vc)) -- 2.7.4