From: Andrew Donnellan <ajd@linux.ibm.com>
To: Russell Currey <ruscur@russell.cc>, linuxppc-dev@lists.ozlabs.org
Cc: kernel-hardening@lists.openwall.com, jniethe5@gmail.com,
npiggin@gmail.com, joel@jms.id.au, dja@axtens.net
Subject: Re: [PATCH v5 8/8] powerpc/mm: Disable set_memory() routines when strict RWX isn't enabled
Date: Wed, 26 Feb 2020 17:38:29 +1100 [thread overview]
Message-ID: <c560b6bb-1a42-bf50-5122-7912771e1481@linux.ibm.com> (raw)
In-Reply-To: <20200226063551.65363-9-ruscur@russell.cc>
On 26/2/20 5:35 pm, Russell Currey wrote:
> There are a couple of reasons that the set_memory() functions are
> problematic when STRICT_KERNEL_RWX isn't enabled:
>
> - The linear mapping is a different size and apply_to_page_range()
> may modify a giant section, breaking everything
> - patch_instruction() doesn't know to work around a page being marked
> RO, and will subsequently crash
>
> The latter can be replicated by building a kernel with the set_memory()
> patches but with STRICT_KERNEL_RWX off and running ftracetest.
>
> Reported-by: Jordan Niethe <jniethe5@gmail.com>
> Signed-off-by: Russell Currey <ruscur@russell.cc>
Can we squash this in earlier in the series for the sake of bisectability?
--
Andrew Donnellan OzLabs, ADL Canberra
ajd@linux.ibm.com IBM Australia Limited
next prev parent reply other threads:[~2020-02-26 6:58 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 6:35 [PATCH v5 0/8] set_memory() routines and STRICT_MODULE_RWX Russell Currey
2020-02-26 6:35 ` [PATCH v5 1/8] powerpc/mm: Implement set_memory() routines Russell Currey
2020-02-26 6:35 ` [PATCH v5 2/8] powerpc/kprobes: Mark newly allocated probes as RO Russell Currey
2020-02-26 6:35 ` [PATCH v5 3/8] powerpc/mm/ptdump: debugfs handler for W+X checks at runtime Russell Currey
2020-02-26 21:52 ` Kees Cook
2022-04-06 18:55 ` Kees Cook
2022-04-07 7:39 ` Christophe Leroy
2020-02-26 6:35 ` [PATCH v5 4/8] powerpc: Set ARCH_HAS_STRICT_MODULE_RWX Russell Currey
2020-02-26 6:35 ` [PATCH v5 5/8] powerpc/configs: Enable STRICT_MODULE_RWX in skiroot_defconfig Russell Currey
2020-02-26 6:35 ` [PATCH v5 6/8] powerpc/mm: implement set_memory_attr() Russell Currey
2020-02-26 6:35 ` [PATCH v5 7/8] powerpc/32: use set_memory_attr() Russell Currey
2020-02-26 6:35 ` [PATCH v5 8/8] powerpc/mm: Disable set_memory() routines when strict RWX isn't enabled Russell Currey
2020-02-26 6:38 ` Andrew Donnellan [this message]
2020-02-26 7:29 ` Christophe Leroy
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