On Tue, Aug 25, 2020 at 06:59:35PM +0200, Greg KH wrote: > On Tue, Aug 25, 2020 at 12:48:04PM -0400, Peilin Ye wrote: > > Hi all, > > > > Link: https://syzkaller.appspot.com/bug?id=f332576321998d36cd07d09c9c1268cfed1895c9 > > > > As reported by syzbot, vcs_read_buf() is overflowing `con_buf16`, since > > this patch removed the following check: > > > > - if (count > CON_BUF_SIZE) { > > - count = CON_BUF_SIZE; > > - filled = count - pos; > > - } > > > > Decreasing `count` by `min(HEADER_SIZE - pos, count)` bypasses this check. > > Additionally, this patch also removed updates to `skip` and `filled`. > > > > What should we do in order to fix it? > > This patch is already reverted, and it has been discussed a bit as to > how to do this properly if you look at the email where this was reported > to us. Ah, syzbot has reported this issue as two different bugs...I started looking into it without noticing your discussion under another thread. Sorry, Peilin Ye
