vt: fix unicode buffer corruption when deleting characters

commit 1581dafaf0d34bc9c428a794a22110d7046d186d upstream.

This is the same issue that was fixed for the VGA text buffer in commit
39cdb68c64d8 ("vt: fix memory overlapping when deleting chars in the
buffer"). The cure is also the same i.e. replace memcpy() with memmove()
due to the overlaping buffers.

Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Fixes: 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition")
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/sn184on2-3p0q-0qrq-0218-895349s4753o@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 6617d3a8e84c953dac07409a0d6986addb0282f6..52e6ca1ba21dfcdf0f421e415e0a10b109f9cb1b 100644 (file)
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -381,7 +381,7 @@ static void vc_uniscr_delete(struct vc_data *vc, unsigned int nr)
                u32 *ln = vc->vc_uni_lines[vc->state.y];
                unsigned int x = vc->state.x, cols = vc->vc_cols;
 
-               memcpy(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
+               memmove(&ln[x], &ln[x + nr], (cols - x - nr) * sizeof(*ln));
                memset32(&ln[cols - nr], ' ', nr);
        }
 }