Re: [PATCH v3 0/2] iov_iter: allow iov_iter_get_pages_alloc to allocate more pages per call

[Al Viro]

On Sun, Feb 05, 2017 at 09:15:24PM +0100, Miklos Szeredi wrote:

> That case is fine.   But nothing guarantees that fuse_abort_conn()
> won't be called (in the non-deadlock case) when data is being copied
> to the request args.  Ending the request at such a point could easily
> lead to use after free,

So why not leave ending it to your fuse_dev_do_write()/fuse_dev_do_read()?
See the reply I'd just sent (your mail arrived while I'd been writing that
one - saw it only after I'd sent mine).

Basically, what if we keep FR_LOCKED through *all* fuse_dev_do_{read,write}(),
rather than dropping and regaining it many times and have fuse_abort_conn()
skip request_end() on FR_LOCKED ones?