Add check for vc_cons[logo_shown].d, as it can be released by vt_ioctl(VT_DISALLOCATE).
Reported-by: syzbot+732528bae351682f1f27@syzkaller.appspotmail.com Signed-off-by: Qiujun Huang hqjagain@gmail.com --- drivers/video/fbdev/core/fbcon.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index bb6ae995c2e5..7ee0f7b55829 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2254,7 +2254,7 @@ static int fbcon_switch(struct vc_data *vc) fbcon_update_softback(vc); }
- if (logo_shown >= 0) { + if (logo_shown >= 0 && vc_cons_allocated(logo_shown)) { struct vc_data *conp2 = vc_cons[logo_shown].d;
if (conp2->vc_top == logo_lines @@ -2852,7 +2852,7 @@ static void fbcon_scrolldelta(struct vc_data *vc, int lines) return; if (vc->vc_mode != KD_TEXT || !lines) return; - if (logo_shown >= 0) { + if (logo_shown >= 0 && vc_cons_allocated(logo_shown)) { struct vc_data *conp2 = vc_cons[logo_shown].d;
if (conp2->vc_top == logo_lines