Messages in this thread | | | From | Miklos Szeredi <> | Date | Mon, 20 Feb 2017 16:16:04 +0100 | Subject | Re: [PATCH 0/9] overlay: fix inconsistency of ro file after copy-up |
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On Sun, Feb 19, 2017 at 10:14 AM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> This is one hell of a DoS vector - it's really easy to eat tons of struct > file that way. Preparatory parts of that series make sense on their own, > but your "let's allocate a struct file, call ->open() and schedule that > struct file for closing upon the exit to userland on each kernel_read()" > is not.
Found a couple of instances of this pattern (haven't looked very hard, possibly there's more):
nfsd_read() cachefiles_write_page()
How come this hasn't been a problem for them?
Would flush_delayed_fput() work here? I couldn't really find what the locking issues with synchronous fputs were.
Thanks, Miklos
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