On Sun, Mar 29, 2020 at 12:31 AM Daniel Vetter daniel.vetter@ffwll.ch wrote:
On Sat, Mar 28, 2020 at 4:15 PM Qiujun Huang hqjagain@gmail.com wrote:
Add check for vc_cons[logo_shown].d, as it can be released by vt_ioctl(VT_DISALLOCATE).
Can you pls link to the syzbot report and distill the essence of the crash/issue here in the commit message? As-is a bit unclear what's going on. Patch itself looks correct.
https://lkml.org/lkml/2020/3/27/403 Thanks.
Thanks, Daniel
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-- 2.17.1
-- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch