On Thu, Feb 10, 2022 at 10:15:52AM +0000, Lee Jones wrote: > On Wed, 09 Feb 2022, Darrick J. Wong wrote: > > > On Wed, Feb 09, 2022 at 08:52:43AM +0000, Lee Jones wrote: > > > This reverts commit 60263d5889e6dc5987dc51b801be4955ff2e4aa7. > > > > > > Reverting since this commit opens a potential avenue for abuse. > > > > What kind of abuse? Did you conclude there's an avenue solely because > > some combination of userspace rigging produced a BUG warning? Or is > > this a real problem that someone found? > > Genuine question: Is the ability for userspace to crash the kernel > not enough to cause concern? I would have thought that we'd want to > prevent this. The kernel doesn't crash. It's a BUG(). That means it kills the task which caused the BUG(). If you've specified that the kernel should crash on seeing a BUG(), well, you made that decision, and you get to live with the consequences. > The link provided doesn't contain any further analysis. Only the > reproducer and kernel configuration used, which are both too large to > enter into a Git commit. But not too large to put in an email. Which you should have sent to begin with, not a stupid reversion commit. > > OH WAIT, you're running this on the Android 5.10 kernel, aren't you? > > The BUG report came from page_buffers failing to find any buffer heads > > attached to the page. > > https://android.googlesource.com/kernel/common/+/refs/heads/android12-5.10-2022-02/fs/ext4/inode.c#2647 > > Yes, the H/W I have to prototype these on is a phone and the report > that came in was specifically built against the aforementioned > kernel. > > > Yeah, don't care. > > "There is nothing to worry about, as it's intended behaviour"? No. You've come in like a fucking meteorite full of arrogance and ignorance. Nobody's reacting well to you right now. Start again, write a good bug report in a new thread.
