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From: Jeff Xu <jeffxu@chromium.org>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	 akpm@linux-foundation.org, linux-hardening@vger.kernel.org,
	 Jorge Lucangeli Obes <jorgelo@chromium.org>
Subject: mprotect outbound check.
Date: Mon, 15 May 2023 11:00:27 -0700	[thread overview]
Message-ID: <CABi2SkXjN+5iFoBhxk71t3cmunTk-s=rB4T7qo0UQRh17s49PQ@mail.gmail.com> (raw)

Noticed there is a slight change for mprotect between 6.1 and 6.4 RC1

For example:
Consider the case below:
1 mmap(0x5000000, PAGE_SIZE,  ...)
2 mprotect(0x5000000, PAGE_SIZE*4, ...)

in 6.1 and before, 2 will fail, and in 6.4 RC1, it will pass.

I know that munmap will accept out-of-bound cases like this (because
memory is freed anyway).

Is this change intentional ?

Thanks!
Best regards,
-Jeff


             reply	other threads:[~2023-05-15 18:00 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-15 18:00 Jeff Xu [this message]
2023-05-16  1:41 ` Jeff Xu
2023-05-16 16:34   ` Peter Xu
2023-05-16 16:57     ` Liam R. Howlett

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