1 files changed, 43 insertions, 38 deletions

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 8a4e7879a7a6..f4ac5ec5dc02 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -762,10 +762,19 @@ static const struct tty_port_operations vc_port_ops = {
 	.destruct = vc_port_destruct,
 };
 
+/*
+ * Change # of rows and columns (0 means unchanged/the size of fg_console)
+ * [this is to be used together with some user program
+ * like resize that changes the hardware videomode]
+ */
+#define VC_MAXCOL (32767)
+#define VC_MAXROW (32767)
+
 int vc_allocate(unsigned int currcons)	/* return 0 on success */
 {
 	struct vt_notifier_param param;
 	struct vc_data *vc;
+	int err;
 
 	WARN_CONSOLE_UNLOCKED();
 
@@ -795,6 +804,11 @@ int vc_allocate(unsigned int currcons)	/* return 0 on success */
 	if (!*vc->vc_uni_pagedir_loc)
 		con_set_default_unimap(vc);
 
+	err = -EINVAL;
+	if (vc->vc_cols > VC_MAXCOL || vc->vc_rows > VC_MAXROW ||
+	    vc->vc_screenbuf_size > KMALLOC_MAX_SIZE || !vc->vc_screenbuf_size)
+		goto err_free;
+	err = -ENOMEM;
 	vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL);
 	if (!vc->vc_screenbuf)
 		goto err_free;
@@ -812,7 +826,7 @@ int vc_allocate(unsigned int currcons)	/* return 0 on success */
 err_free:
 	kfree(vc);
 	vc_cons[currcons].d = NULL;
-	return -ENOMEM;
+	return err;
 }
 
 static inline int resize_screen(struct vc_data *vc, int width, int height,
@@ -821,20 +835,12 @@ static inline int resize_screen(struct vc_data *vc, int width, int height,
 	/* Resizes the resolution of the display adapater */
 	int err = 0;
 
-	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
+	if (vc->vc_sw->con_resize)
 		err = vc->vc_sw->con_resize(vc, width, height, user);
 
 	return err;
 }
 
-/*
- * Change # of rows and columns (0 means unchanged/the size of fg_console)
- * [this is to be used together with some user program
- * like resize that changes the hardware videomode]
- */
-#define VC_RESIZE_MAXCOL (32767)
-#define VC_RESIZE_MAXROW (32767)
-
 /**
  *	vc_do_resize	-	resizing method for the tty
  *	@tty: tty being resized
@@ -859,7 +865,7 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
 	unsigned int old_rows, old_row_size;
 	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
 	unsigned int user;
-	unsigned short *newscreen;
+	unsigned short *oldscreen, *newscreen;
 
 	WARN_CONSOLE_UNLOCKED();
 
@@ -869,7 +875,7 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
 	user = vc->vc_resize_user;
 	vc->vc_resize_user = 0;
 
-	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
+	if (cols > VC_MAXCOL || lines > VC_MAXROW)
 		return -EINVAL;
 
 	new_cols = (cols ? cols : vc->vc_cols);
@@ -877,10 +883,27 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
 	new_row_size = new_cols << 1;
 	new_screen_size = new_row_size * new_rows;
 
-	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
-		return 0;
+	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) {
+		/*
+		 * This function is being called here to cover the case
+		 * where the userspace calls the FBIOPUT_VSCREENINFO twice,
+		 * passing the same fb_var_screeninfo containing the fields
+		 * yres/xres equal to a number non-multiple of vc_font.height
+		 * and yres_virtual/xres_virtual equal to number lesser than the
+		 * vc_font.height and yres/xres.
+		 * In the second call, the struct fb_var_screeninfo isn't
+		 * being modified by the underlying driver because of the
+		 * if above, and this causes the fbcon_display->vrows to become
+		 * negative and it eventually leads to out-of-bound
+		 * access by the imageblit function.
+		 * To give the correct values to the struct and to not have
+		 * to deal with possible errors from the code below, we call
+		 * the resize_screen here as well.
+		 */
+		return resize_screen(vc, new_cols, new_rows, user);
+	}
 
-	if (new_screen_size > KMALLOC_MAX_SIZE)
+	if (new_screen_size > KMALLOC_MAX_SIZE || !new_screen_size)
 		return -EINVAL;
 	newscreen = kzalloc(new_screen_size, GFP_USER);
 	if (!newscreen)
@@ -941,10 +964,11 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
 	if (new_scr_end > new_origin)
 		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
 			    new_scr_end - new_origin);
-	kfree(vc->vc_screenbuf);
+	oldscreen = vc->vc_screenbuf;
 	vc->vc_screenbuf = newscreen;
 	vc->vc_screenbuf_size = new_screen_size;
 	set_origin(vc);
+	kfree(oldscreen);
 
 	/* do part of a reset_terminal() */
 	vc->vc_top = 0;
@@ -3031,6 +3055,7 @@ static int __init con_init(void)
 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
 		tty_port_init(&vc->port);
 		visual_init(vc, currcons, 1);
+		/* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
 		vc_init(vc, vc->vc_rows, vc->vc_cols,
 			currcons || !vc->vc_sw->con_save_screen);
@@ -4219,27 +4244,6 @@ static int con_font_default(struct vc_data *vc, struct console_font_op *op)
 	return rc;
 }
 
-static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
-{
-	int con = op->height;
-	int rc;
-
-
-	console_lock();
-	if (vc->vc_mode != KD_TEXT)
-		rc = -EINVAL;
-	else if (!vc->vc_sw->con_font_copy)
-		rc = -ENOSYS;
-	else if (con < 0 || !vc_cons_allocated(con))
-		rc = -ENOTTY;
-	else if (con == vc->vc_num)	/* nothing to do */
-		rc = 0;
-	else
-		rc = vc->vc_sw->con_font_copy(vc, con);
-	console_unlock();
-	return rc;
-}
-
 int con_font_op(struct vc_data *vc, struct console_font_op *op)
 {
 	switch (op->op) {
@@ -4250,7 +4254,8 @@ int con_font_op(struct vc_data *vc, struct console_font_op *op)
 	case KD_FONT_OP_SET_DEFAULT:
 		return con_font_default(vc, op);
 	case KD_FONT_OP_COPY:
-		return con_font_copy(vc, op);
+		/* was buggy and never really used */
+		return -EINVAL;
 	}
 	return -ENOSYS;
 }