From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: akpm@linux-foundation.org, hch@lst.de,
Michael Ellerman <mpe@ellerman.id.au>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
viro@zeniv.linux.org.uk,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2] powerpc/mm: Fix KUAP warning by providing copy_from_kernel_nofault_allowed()
Date: Thu, 10 Dec 2020 11:23:57 +1100 (AEDT) [thread overview]
Message-ID: <160755982586.1285738.12667869391229651303.b4-ty@ellerman.id.au> (raw)
In-Reply-To: <18bcb456d32a3e74f5ae241fd6f1580c092d07f5.1607360230.git.christophe.leroy@csgroup.eu>
On Mon, 7 Dec 2020 16:58:01 +0000 (UTC), Christophe Leroy wrote:
> Since commit c33165253492 ("powerpc: use non-set_fs based maccess
> routines"), userspace access is not granted anymore when using
> copy_from_kernel_nofault()
>
> However, kthread_probe_data() uses copy_from_kernel_nofault()
> to check validity of pointers. When the pointer is NULL,
> it points to userspace, leading to a KUAP fault and triggering
> the following big hammer warning many times when you request
> a sysrq "show task":
>
> [...]
Applied to powerpc/fixes.
[1/1] powerpc/mm: Fix KUAP warning by providing copy_from_kernel_nofault_allowed()
https://git.kernel.org/powerpc/c/5eedf9fe8db23313df104576845cec5f481b9b60
cheers
prev parent reply other threads:[~2020-12-10 0:24 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-07 16:58 [PATCH v2] powerpc/mm: Fix KUAP warning by providing copy_from_kernel_nofault_allowed() Christophe Leroy
2020-12-10 0:23 ` Michael Ellerman [this message]
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