From: Nick Desaulniers <ndesaulniers@google.com>
To: Sami Tolvanen <samitolvanen@google.com>
Cc: Kees Cook <keescook@chromium.org>,
Nathan Chancellor <nathan@kernel.org>,
Masahiro Yamada <masahiroy@kernel.org>,
Will Deacon <will@kernel.org>, Jessica Yu <jeyu@kernel.org>,
Arnd Bergmann <arnd@arndb.de>, Tejun Heo <tj@kernel.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
Christoph Hellwig <hch@infradead.org>, bpf <bpf@vger.kernel.org>,
linux-hardening@vger.kernel.org,
linux-arch <linux-arch@vger.kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
PCI <linux-pci@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 10/17] lkdtm: use __va_function
Date: Thu, 18 Mar 2021 11:43:29 -0700 [thread overview]
Message-ID: <CAKwvOdkn7MY+-9D0DQ-18OR=s1XmgPaP7VchCm6VV5kYuKSAkA@mail.gmail.com> (raw)
In-Reply-To: <20210318171111.706303-11-samitolvanen@google.com>
On Thu, Mar 18, 2021 at 10:11 AM Sami Tolvanen <samitolvanen@google.com> wrote:
>
> To ensure we take the actual address of a function in kernel text, use
> __va_function. Otherwise, with CONFIG_CFI_CLANG, the compiler replaces
> the address with a pointer to the CFI jump table, which is actually in
> the module when compiled with CONFIG_LKDTM=m.
Should patch 10 and 12 be reordered against one another? Otherwise it
looks like 12 defines __va_function while 10 uses it?
>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> Acked-by: Kees Cook <keescook@chromium.org>
> ---
> drivers/misc/lkdtm/usercopy.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/lkdtm/usercopy.c b/drivers/misc/lkdtm/usercopy.c
> index 109e8d4302c1..d173d6175c87 100644
> --- a/drivers/misc/lkdtm/usercopy.c
> +++ b/drivers/misc/lkdtm/usercopy.c
> @@ -314,7 +314,7 @@ void lkdtm_USERCOPY_KERNEL(void)
>
> pr_info("attempting bad copy_to_user from kernel text: %px\n",
> vm_mmap);
> - if (copy_to_user((void __user *)user_addr, vm_mmap,
> + if (copy_to_user((void __user *)user_addr, __va_function(vm_mmap),
> unconst + PAGE_SIZE)) {
> pr_warn("copy_to_user failed, but lacked Oops\n");
> goto free_user;
> --
> 2.31.0.291.g576ba9dcdaf-goog
>
--
Thanks,
~Nick Desaulniers
next prev parent reply other threads:[~2021-03-18 18:44 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 17:10 [PATCH v2 00/17] Add support for Clang CFI Sami Tolvanen
2021-03-18 17:10 ` [PATCH v2 01/17] add " Sami Tolvanen
2021-03-18 22:29 ` Peter Zijlstra
2021-03-18 23:48 ` Sami Tolvanen
2021-03-19 12:26 ` Peter Zijlstra
2021-03-19 13:52 ` Paul E. McKenney
2021-03-19 16:17 ` Sami Tolvanen
2021-03-19 17:03 ` Paul E. McKenney
2021-03-18 17:10 ` [PATCH v2 02/17] cfi: add __cficanonical Sami Tolvanen
2021-03-18 17:49 ` Nick Desaulniers
2021-03-18 17:10 ` [PATCH v2 03/17] mm: add generic __va_function and __pa_function macros Sami Tolvanen
2021-03-18 17:10 ` [PATCH v2 04/17] module: ensure __cfi_check alignment Sami Tolvanen
2021-03-18 19:27 ` Nick Desaulniers
2021-03-18 21:43 ` Sami Tolvanen
2021-03-18 17:10 ` [PATCH v2 05/17] workqueue: use WARN_ON_FUNCTION_MISMATCH Sami Tolvanen
2021-03-18 18:50 ` Nick Desaulniers
2021-03-18 21:38 ` Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 06/17] kthread: " Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 07/17] kallsyms: strip ThinLTO hashes from static functions Sami Tolvanen
2021-03-18 19:00 ` Nick Desaulniers
2021-03-18 21:41 ` Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 08/17] bpf: disable CFI in dispatcher functions Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 09/17] lib/list_sort: fix function type mismatches Sami Tolvanen
2021-03-18 18:31 ` Nick Desaulniers
2021-03-18 21:31 ` Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 10/17] lkdtm: use __va_function Sami Tolvanen
2021-03-18 18:43 ` Nick Desaulniers [this message]
2021-03-18 18:45 ` Nick Desaulniers
2021-03-18 17:11 ` [PATCH v2 11/17] psci: use __pa_function for cpu_resume Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 12/17] arm64: implement __va_function Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 13/17] arm64: use __pa_function Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 14/17] arm64: add __nocfi to functions that jump to a physical address Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 15/17] arm64: add __nocfi to __apply_alternatives Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 16/17] KVM: arm64: Disable CFI for nVHE Sami Tolvanen
2021-03-18 17:11 ` [PATCH v2 17/17] arm64: allow CONFIG_CFI_CLANG to be selected Sami Tolvanen
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