Re: [PATCH 2/2] Perform check in iov_iter_fault_in_readable() by check_readable_bytes()

[Andi Kleen]

> ptr = mmap(0, page_size, ....);
> ...
> write(fd, ptr + page_size - 256, 512);
> 
> Write() will fail here, but it can write first 256 bytes. Previously,
> all 512 bytes were proceeded, but last 256 bytes were zeroed, and
> sys_write() returned 256. Not very nice too. 

Is that really something that users rely on? It looks like a seriously
broken user program. Which one is that? (just that I can avoid it :)

-Andi

-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/