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Date:   Tue, 23 Jul 2019 19:58:50 +0200
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Subject: [PATCH v19 13/15] tee/shm: untag user pointers in tee_shm_register
From:   Andrey Konovalov <andreyknvl@google.com>
To:     linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org,
        linux-media@vger.kernel.org, kvm@vger.kernel.org,
        linux-kselftest@vger.kernel.org
Cc:     Catalin Marinas <catalin.marinas@arm.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Kees Cook <keescook@chromium.org>,
        Yishai Hadas <yishaih@mellanox.com>,
        Felix Kuehling <Felix.Kuehling@amd.com>,
        Alexander Deucher <Alexander.Deucher@amd.com>,
        Christian Koenig <Christian.Koenig@amd.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Jens Wiklander <jens.wiklander@linaro.org>,
        Alex Williamson <alex.williamson@redhat.com>,
        Leon Romanovsky <leon@kernel.org>,
        Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
        Dave Martin <Dave.Martin@arm.com>,
        Khalid Aziz <khalid.aziz@oracle.com>, enh <enh@google.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Christoph Hellwig <hch@infradead.org>,
        Dmitry Vyukov <dvyukov@google.com>,
        Kostya Serebryany <kcc@google.com>,
        Evgeniy Stepanov <eugenis@google.com>,
        Lee Smith <Lee.Smith@arm.com>,
        Ramana Radhakrishnan <Ramana.Radhakrishnan@arm.com>,
        Jacob Bramley <Jacob.Bramley@arm.com>,
        Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Kevin Brodsky <kevin.brodsky@arm.com>,
        Szabolcs Nagy <Szabolcs.Nagy@arm.com>,
        Andrey Konovalov <andreyknvl@google.com>
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Precedence: bulk

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

tee_shm_register()->optee_shm_unregister()->check_mem_type() uses provided
user pointers for vma lookups (via __check_mem_type()), which can only by
done with untagged pointers.

Untag user pointers in this function.

Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 drivers/tee/tee_shm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 2da026fd12c9..09ddcd06c715 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -254,6 +254,7 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
 	shm->teedev = teedev;
 	shm->ctx = ctx;
 	shm->id = -1;
+	addr = untagged_addr(addr);
 	start = rounddown(addr, PAGE_SIZE);
 	shm->offset = addr - start;
 	shm->size = length;
-- 
2.22.0.709.g102302147b-goog