[PATCH] fbcon: fix null-ptr-deref in fbcon_switch

2020-03-30 Thread Qiujun Huang
Add check for vc_cons[logo_shown].d, as it can be released by vt_ioctl(VT_DISALLOCATE). Reported-by: syzbot+732528bae351682f1...@syzkaller.appspotmail.com Signed-off-by: Qiujun Huang --- drivers/video/fbdev/core/fbcon.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git

Re: [PATCH] fbcon: fix null-ptr-deref in fbcon_switch

2020-03-30 Thread Qiujun Huang
On Sun, Mar 29, 2020 at 12:31 AM Daniel Vetter wrote: > > On Sat, Mar 28, 2020 at 4:15 PM Qiujun Huang 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

Re: [PATCH] fbcon: fix null-ptr-deref in fbcon_switch

2020-03-30 Thread Qiujun Huang
On Sun, Mar 29, 2020 at 2:13 AM Sam Ravnborg wrote: > > Hi Qiujun > > Thanks for looking into the sysbot bugs. > > On Sat, Mar 28, 2020 at 11:15:10PM +0800, Qiujun Huang wrote: > > Add check for vc_cons[logo_shown].d, as it can be released by > > vt_ioctl(VT_DISALLOCATE). > > > > Reported-by:

Re: [PATCH] fbcon: fix null-ptr-deref in fbcon_switch

2020-03-28 Thread Sam Ravnborg
Hi Qiujun Thanks for looking into the sysbot bugs. On Sat, Mar 28, 2020 at 11:15:10PM +0800, Qiujun Huang wrote: > Add check for vc_cons[logo_shown].d, as it can be released by > vt_ioctl(VT_DISALLOCATE). > > Reported-by: syzbot+732528bae351682f1...@syzkaller.appspotmail.com > Signed-off-by:

Re: [PATCH] fbcon: fix null-ptr-deref in fbcon_switch

2020-03-28 Thread Daniel Vetter
On Sat, Mar 28, 2020 at 4:15 PM Qiujun Huang 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