Re: KASAN: use-after-free Read in path_lookupat

From: Alexei Starovoitov
Date: Mon Mar 25 2019 - 19:44:45 EST


On Mon, Mar 25, 2019 at 11:37:32PM +0000, Al Viro wrote:
>
> For debugfs it's clearly "use default ->evict_inode(), have explicit
> ->destroy_inode() using free_inode_nonrcu()" - there we have nothing
> else done in ->evict_inode() and kfree is obviously safe in softirq.
> I'll post that (or push to vfs.git#fixes), along with minimal fixes
> for other 3. If bpf_any_put() is softirq-safe, we'll have the full
> set for -stable and the rest could be done on top of that.

Yes. bpf_any_put() is safe to be called from softirq.